Existing Annotations Review

GO Term	Evidence	Action	Reason
GO:0005615 extracellular space	IBA GO_REF:0000033	ACCEPT	Summary: Decorin is a secreted extracellular matrix proteoglycan. IBA annotation based on phylogenetic inference correctly captures decorin's localization to extracellular space where it performs its core functions in collagen fibril organization and TGF-beta sequestration. Reason: This is a core cellular component annotation supported by extensive experimental evidence (UniProt CC line "Secreted, extracellular space, extracellular matrix"), IBA phylogenetic inference, and multiple proteomic studies. Decorin functions exclusively in the extracellular space. Supporting Evidence: GO_REF:0000033 IBA annotation inferences using phylogenetic trees Reactome:R-HSA-2327909 DCN consists of a core protein of approximately 40 kDa attached to a single chondroitin or dermatan sulfate glycosaminoglycan (GAG) chain. file:human/DCN/DCN-deep-research-falcon.md model: Edison Scientific Literature
GO:0005576 extracellular region	IEA GO_REF:0000044	ACCEPT	Summary: Broad parent term of extracellular space. While correct, this is less specific than the IBA annotation to extracellular space (GO:0005615) and extracellular matrix (GO:0031012). Reason: Correct but general IEA annotation based on UniProt subcellular location vocabulary. The more specific child terms (extracellular space, extracellular matrix) better capture decorin's precise localization, but this parent term is not incorrect. Supporting Evidence: GO_REF:0000044 Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location vocabulary mapping
GO:0005539 glycosaminoglycan binding	IEA GO_REF:0000107	MARK AS OVER ANNOTATED	Summary: Decorin itself is a proteoglycan containing a GAG chain, and may have self-association properties. However, the primary molecular function is collagen binding and TGF-beta binding rather than GAG binding per se. Reason: While decorin has a GAG chain (dermatan/chondroitin sulfate) attached, GAG binding is not a prominently reported molecular function. The annotation likely derives from domain-based inference (IEA from Ensembl) but decorin's core functions are collagen binding and growth factor binding, not GAG binding. May reflect some self-association or interaction with other proteoglycans, but this is not well-documented as a primary function. Supporting Evidence: GO_REF:0000107 Automatic transfer of experimentally verified manual GO annotation data to orthologs using Ensembl Compara
GO:0050840 extracellular matrix binding	IEA GO_REF:0000107	MODIFY	Summary: Too vague. Decorin specifically binds collagen fibrils (types I, II, III, VI), fibronectin, and thrombospondin-1. The more specific molecular function terms should be used. Reason: This broad term does not capture decorin's specific binding activities. Decorin has well-characterized binding to specific ECM components via its leucine-rich repeats. Should be replaced with more specific molecular function terms for collagen binding and fibronectin binding. Proposed replacements: collagen binding fibronectin binding Supporting Evidence: Reactome:R-HSA-2327909 It interacts with collagen types I, II (Vogel et al. 1984), III (Witos et al. 2011), V (Whinna et al. 1993), VI (Bidanset et al. 1992) and XIV (Ehnis et al. 1997). PMID:1747115 Decorin, an interstitial small proteoglycan, was shown to interact with fibronectin via its core protein. In a solid-phase assay, both high-affinity (KD values between 10 and 20 nM) and low-affinity (KD values between 110 and 130 nM) binding sites were found.
GO:0005515 protein binding	IPI PMID:1747115 Interaction of the small proteoglycan decorin with fibronect...	MODIFY	Summary: Vague term. PMID:1747115 specifically demonstrates fibronectin binding with measured KD values (10-20 nM high affinity, 110-130 nM low affinity). The specific molecular function term should be used instead. Reason: The term "protein binding" is uninformative per curation guidelines. The cited paper demonstrates specific fibronectin binding via decorin's core protein LRR domain. This should be annotated with the specific molecular function GO:0001968 (fibronectin binding). Proposed replacements: fibronectin binding Supporting Evidence: PMID:1747115 Decorin, an interstitial small proteoglycan, was shown to interact with fibronectin via its core protein.
GO:0005515 protein binding	IPI PMID:20026052 Decorin is processed by three isoforms of bone morphogenetic...	REMOVE	Summary: Vague term. Paper describes decorin processing by bone morphogenetic protein-1 (BMP1) isoforms. This is substrate-enzyme interaction, not a molecular function annotation for decorin itself. Reason: The term "protein binding" is uninformative per curation guidelines. PMID:20026052 demonstrates that decorin is processed/cleaved by BMP1, which is relevant for decorin maturation but does not represent a molecular function of decorin. Being a substrate for proteolytic processing is not appropriately annotated as "protein binding." Supporting Evidence: PMID:20026052 Decorin is processed by three isoforms of bone morphogenetic protein-1 (BMP1).
GO:0005515 protein binding	IPI PMID:25331875 Xylose phosphorylation functions as a molecular switch to re...	REMOVE	Summary: Vague term. Paper concerns xylose phosphorylation regulation of proteoglycan biosynthesis. This is about decorin biosynthesis machinery, not decorin's molecular function. Reason: The term "protein binding" is uninformative per curation guidelines. PMID:25331875 discusses xylose phosphorylation as a regulatory switch in proteoglycan biosynthesis. This interaction is part of decorin's biosynthesis pathway, not a functional molecular activity of the mature decorin protein. Should not be annotated as "protein binding." Supporting Evidence: PMID:25331875 Xylose phosphorylation functions as a molecular switch to regulate proteoglycan biosynthesis.
GO:0005515 protein binding	IPI PMID:25789606 A secretory kinase complex regulates extracellular protein p...	REMOVE	Summary: Vague term. Paper describes a secretory kinase complex (FAM20C) that phosphorylates extracellular proteins including decorin. This is enzyme-substrate interaction during biosynthesis. Reason: The term "protein binding" is uninformative per curation guidelines. PMID:25789606 demonstrates that decorin is phosphorylated by the secretory kinase FAM20C. This enzyme-substrate interaction during decorin biosynthesis/modification does not represent a molecular function of decorin itself and should not be annotated as "protein binding." Supporting Evidence: PMID:25789606 A secretory kinase complex regulates extracellular protein phosphorylation.
GO:0005576 extracellular region	TAS Reactome:R-HSA-2022056	ACCEPT	Summary: Reactome pathway annotation for DSPG/CSPG translocation to lysosome for degradation. Decorin (as a dermatan sulfate proteoglycan) is secreted to extracellular region and eventually degraded. Correct but redundant with other extracellular annotations. Reason: Correct annotation from Reactome pathway curation. Decorin as a dermatan/chondroitin sulfate proteoglycan is secreted to extracellular region before eventual lysosomal degradation. While redundant with IBA and IEA annotations to the same term, TAS evidence from curated pathways is valid. Supporting Evidence: Reactome:R-HSA-2022056 DSPG and CSPG translocate to the lysosome for degradation
GO:0005576 extracellular region	TAS Reactome:R-HSA-2022065	ACCEPT	Summary: Reactome pathway annotation for DSPG secretion. Decorin as a dermatan sulfate proteoglycan is secreted to extracellular region. Correct but redundant with other extracellular annotations. Reason: Correct annotation from Reactome pathway curation showing decorin secretion to extracellular space. While redundant with other annotations, TAS evidence from curated pathways adds value by connecting to specific biological process (DSPG secretion). Supporting Evidence: Reactome:R-HSA-2022065 Various forms of dermatan sulfate are excreted from the cell once formed
GO:0005576 extracellular region	TAS Reactome:R-HSA-2022911	ACCEPT	Summary: Reactome pathway annotation for CSPG secretion. Decorin can carry chondroitin sulfate GAG chain and is secreted to extracellular region. Correct but redundant with other extracellular annotations. Reason: Correct annotation from Reactome pathway curation. Decorin can exist as chondroitin sulfate proteoglycan (CSPG) or dermatan sulfate proteoglycan (DSPG) depending on tissue. TAS evidence from curated secretion pathway is valid though redundant. Supporting Evidence: Reactome:R-HSA-2022911 they are secreted out into the extracellular matrix (ECM)
GO:0005796 Golgi lumen	TAS Reactome:R-HSA-2022065	KEEP AS NON CORE	Summary: Reactome pathway annotation for DSPG biosynthesis/modification in Golgi during secretion. Decorin transiently passes through Golgi lumen where GAG chain is modified (SO4 transfer to GalNAc by CHST14). Reason: Correct annotation reflecting decorin's transit through the Golgi lumen during biosynthesis and GAG chain modification. However, this is a transient biosynthetic localization, not decorin's mature functional localization. The mature, functional protein resides in extracellular matrix. Marking as non-core to distinguish from the primary functional location. Supporting Evidence: Reactome:R-HSA-2022065 unknown but most likely involves the trans-golgi network
GO:0005796 Golgi lumen	TAS Reactome:R-HSA-2022911	KEEP AS NON CORE	Summary: Reactome pathway annotation for CSPG biosynthesis/secretion. Decorin transiently passes through Golgi lumen during biosynthesis where GAG chain modifications occur. Reason: Correct annotation reflecting transient Golgi localization during proteoglycan biosynthesis. Decorin's chondroitin/dermatan sulfate GAG chain is assembled and modified in Golgi. However, this is biosynthetic transit, not the mature functional localization. Marking as non-core. Supporting Evidence: Reactome:R-HSA-2022911 they are secreted out into the extracellular matrix
GO:0005796 Golgi lumen	TAS Reactome:R-HSA-9940993	KEEP AS NON CORE	Summary: Reactome pathway for xylose dephosphorylation by PXYLP1 during GAG chain biosynthesis. Decorin present in Golgi lumen during this modification step. Reason: Correct annotation from Reactome GAG biosynthesis pathway. PXYLP1 dephosphorylates the xylose moiety on the tetrasaccharide linker region of decorin's GAG chain attachment site in Golgi. Transient biosynthetic localization, not core functional location. Marking as non-core. Supporting Evidence: Reactome:R-HSA-9940993 PXYLP1 dephosphorylates Xyl moiety
GO:0005796 Golgi lumen	TAS Reactome:R-HSA-9941039	KEEP AS NON CORE	Summary: Reactome pathway for xylose phosphorylation by FAM20B during GAG chain biosynthesis. Decorin present in Golgi lumen during this modification step. Reason: Correct annotation from Reactome GAG biosynthesis pathway. FAM20B phosphorylates the xylose moiety on decorin's GAG attachment site linker in Golgi. This phosphorylation acts as a regulatory switch for proteoglycan biosynthesis. Transient biosynthetic localization. Marking as non-core. Supporting Evidence: Reactome:R-HSA-9941039 FAM20B phosphorylates Xyl moiety
GO:0005796 Golgi lumen	TAS Reactome:R-HSA-9941305	KEEP AS NON CORE	Summary: Reactome pathway for sulfate transfer by UST to GlcA-GalNAc-6-sulfate during dermatan sulfate biosynthesis. Decorin present in Golgi during GAG chain sulfation. Reason: Correct annotation from Reactome dermatan sulfate biosynthesis pathway. UST transfers sulfate to position 2 of GlcA in the decorin GAG chain in Golgi lumen. Transient biosynthetic localization during GAG chain modification. Marking as non-core. Supporting Evidence: Reactome:R-HSA-9941305 UST transfers sulfate to (2-)GlcA-GalNAc-6-sulfate
GO:0005796 Golgi lumen	TAS Reactome:R-HSA-9941312	KEEP AS NON CORE	Summary: Reactome pathway for sulfate transfer by CHST15 during GAG biosynthesis. Decorin present in Golgi during chondroitin/dermatan sulfate chain sulfation. Reason: Correct annotation from Reactome GAG biosynthesis pathway. CHST15 transfers sulfate to GalNAc-4-sulfate residues in decorin's GAG chain in Golgi. Transient biosynthetic localization. Marking as non-core. Supporting Evidence: Reactome:R-HSA-9941312 CHST15 transfers sulfate to (6-)GalNAc-4-sulfate
GO:0016239 positive regulation of macroautophagy	IDA PMID:23798385 Decorin causes autophagy in endothelial cells via Peg3.	KEEP AS NON CORE	Summary: Decorin induces autophagy in endothelial cells via VEGFR2 signaling and Peg3 induction, leading to transcriptional activation of Beclin 1 and LC3. This is experimentally demonstrated with direct assays showing autophagosome formation. Reason: Well-supported experimental finding (IDA) from PMID:23798385. Decorin binding to VEGFR2 on endothelial cells triggers Peg3-dependent autophagy and angiogenesis suppression. However, this is a downstream consequence of decorin's receptor binding activity in specific cell types (endothelial cells) rather than a core function. Decorin's core functions are collagen fibril organization and TGF-beta sequestration in the ECM. The autophagy induction represents a secondary signaling effect. Marking as non-core. Supporting Evidence: PMID:23798385 Decorin evoked Peg3-dependent autophagy in both microvascular and macrovascular endothelial cells leading to suppression of angiogenesis.
GO:0016239 positive regulation of macroautophagy	IGI PMID:23798385 Decorin causes autophagy in endothelial cells via Peg3.	KEEP AS NON CORE	Summary: Same biological process as IDA annotation above, but IGI evidence code indicates genetic interaction studies (likely Peg3 or VEGFR2 knockdown experiments) demonstrating decorin's role in autophagy. Reason: Duplicate of the IDA annotation with different evidence code (IGI - inferred from genetic interaction). Same rationale applies - decorin induces autophagy via VEGFR2/Peg3 pathway in endothelial cells. This is a secondary signaling activity rather than core ECM structural function. Marking as non-core. The IGI evidence likely comes from genetic perturbation experiments (siRNA of Peg3 or VEGFR2) showing decorin requires these factors for autophagy induction. Supporting Evidence: PMID:23798385 Peg3 coimmunoprecipitated with Beclin 1 and LC3 and was required for maintaining basal levels of Beclin 1.
GO:0005515 protein binding	IPI PMID:11598131 WISP-1 binds to decorin and biglycan.	MARK AS OVER ANNOTATED	Summary: Vague term. PMID:11598131 shows WISP-1 (CCN4, a matricellular protein) binds to decorin and biglycan. While this is a real interaction, "protein binding" is too uninformative per curation guidelines. Reason: The term "protein binding" is uninformative per curation guidelines. While PMID:11598131 demonstrates a genuine interaction between decorin and WISP-1, this is a peripheral binding partner compared to decorin's core functions (collagen binding, TGF-beta binding, growth factor receptor binding). Without a more specific GO term for WISP-1 binding, this should be marked as over-annotated rather than representing a core molecular function. Supporting Evidence: PMID:11598131 WISP-1 binds to decorin and biglycan.
GO:0030021 extracellular matrix structural constituent conferring compression resistance	RCA PMID:28327460 Comprehensive proteomic characterization of stem cell-derive...	MODIFY	Summary: Incorrect molecular function for decorin. This term (GO:0030021) is appropriate for large aggregating proteoglycans like aggrecan that provide compression resistance in cartilage. Decorin's core function is collagen fibril organization, not compression resistance. Reason: This RCA (inferred from reviewed computational analysis) annotation is a mis-annotation. GO:0030021 describes the ability to resist compression forces, which is the role of large cartilage proteoglycans like aggrecan with multiple GAG chains. Decorin is a small proteoglycan (SLRP) with a single GAG chain whose primary function is regulating collagen fibril assembly and diameter, not providing compression resistance. Should be replaced with GO:0005518 (collagen binding) which represents decorin's actual core molecular function. Proposed replacements: collagen binding Supporting Evidence: Reactome:R-HSA-2327909 DCN binding regulates fibrillogenesis (Vogel et al. 1984, Orgel et al. 2006).
GO:0031012 extracellular matrix	HDA PMID:28327460 Comprehensive proteomic characterization of stem cell-derive...	ACCEPT	Summary: Correct cellular component annotation from HDA (high-throughput direct assay) proteomics. Decorin is a core extracellular matrix proteoglycan. Reason: Accurate annotation based on proteomics characterization of stem cell-derived extracellular matrices. Decorin is a major structural component of the ECM where it regulates collagen fibrillogenesis and sequesters TGF-beta. This is a core localization for decorin's function. Supporting Evidence: PMID:28327460 Comprehensive proteomic characterization of stem cell-derived extracellular matrices.
GO:0030021 extracellular matrix structural constituent conferring compression resistance	RCA PMID:28675934 Characterization of the Extracellular Matrix of Normal and D...	MODIFY	Summary: Incorrect molecular function for decorin. Same issue as other GO:0030021 annotations - decorin regulates collagen fibrillogenesis, not compression resistance. Reason: Mis-annotation from RCA (reviewed computational analysis). Decorin is a small leucine-rich proteoglycan that regulates collagen fibril organization, not a large aggregating proteoglycan that provides compression resistance. This term is inappropriate for decorin's molecular function. Proposed replacements: collagen binding Supporting Evidence: Reactome:R-HSA-2327909 DCN binding regulates fibrillogenesis (Vogel et al. 1984, Orgel et al. 2006).
GO:0031012 extracellular matrix	HDA PMID:28675934 Characterization of the Extracellular Matrix of Normal and D...	ACCEPT	Summary: Correct cellular component annotation from HDA proteomics of normal and diseased tissues. Decorin is a core ECM component. Reason: Accurate annotation based on proteomics characterization of ECM from normal and diseased tissues. Decorin is a fundamental structural proteoglycan of the extracellular matrix. This is a core localization. Supporting Evidence: PMID:28675934 Characterization of the Extracellular Matrix of Normal and Diseased Tissues Using Proteomics.
GO:0030021 extracellular matrix structural constituent conferring compression resistance	ISS GO_REF:0000024	MODIFY	Summary: Incorrect molecular function inferred from sequence similarity. Decorin does not provide compression resistance - it regulates collagen fibril organization. Reason: This ISS (inferred from sequence/structural similarity) annotation is incorrect. While decorin shares sequence similarity with other SLRPs, its molecular function is distinct from large aggregating proteoglycans. Decorin regulates collagen fibril assembly and spacing through direct collagen binding, not compression resistance. Proposed replacements: collagen binding Supporting Evidence: GO_REF:0000024 Manual transfer of experimentally-verified manual GO annotation data to orthologs by curator judgment of sequence similarity.
GO:0030021 extracellular matrix structural constituent conferring compression resistance	RCA PMID:20551380 Proteomics characterization of extracellular space component...	MODIFY	Summary: Incorrect molecular function. Decorin regulates collagen organization, not compression resistance. Same issue as other GO:0030021 annotations. Reason: Mis-annotation from RCA analysis. Decorin's core molecular function is collagen binding and regulation of fibrillogenesis, not providing compression resistance to ECM. Proposed replacements: collagen binding Supporting Evidence: Reactome:R-HSA-2327909 DCN binding regulates fibrillogenesis (Vogel et al. 1984, Orgel et al. 2006).
GO:0030021 extracellular matrix structural constituent conferring compression resistance	RCA PMID:25037231 Extracellular matrix signatures of human primary metastatic ...	MODIFY	Summary: Incorrect molecular function. Decorin regulates collagen organization, not compression resistance. Same issue as other GO:0030021 annotations. Reason: Mis-annotation from RCA of ECM proteomics data. Decorin's molecular function is collagen binding and fibril organization, not compression resistance. Proposed replacements: collagen binding Supporting Evidence: Reactome:R-HSA-2327909 DCN binding regulates fibrillogenesis (Vogel et al. 1984, Orgel et al. 2006).
GO:0030021 extracellular matrix structural constituent conferring compression resistance	RCA PMID:27559042 Glycoproteomics Reveals Decorin Peptides With Anti-Myostatin...	MODIFY	Summary: Incorrect molecular function. Decorin regulates collagen organization, not compression resistance. Same issue as other GO:0030021 annotations. Reason: Mis-annotation from RCA analysis. Decorin is a small proteoglycan that regulates collagen fibril assembly, not a large aggregating proteoglycan that provides compression resistance. Proposed replacements: collagen binding Supporting Evidence: Reactome:R-HSA-2327909 DCN binding regulates fibrillogenesis (Vogel et al. 1984, Orgel et al. 2006).
GO:0031012 extracellular matrix	HDA PMID:25037231 Extracellular matrix signatures of human primary metastatic ...	ACCEPT	Summary: Correct cellular component annotation from HDA proteomics of metastatic colon cancers. Decorin is an ECM component. Reason: Accurate annotation from proteomic analysis of ECM in cancer tissues. Decorin is a core extracellular matrix proteoglycan. Supporting Evidence: PMID:25037231 Extracellular matrix signatures of human primary metastatic colon cancers and their metastases to liver.
GO:0005576 extracellular region	HDA PMID:27068509 Extracellular matrix remodelling in response to venous hyper...	ACCEPT	Summary: Correct cellular component annotation from HDA proteomics of human varicose veins. Decorin is in extracellular region/ECM. Reason: Accurate annotation from proteomic analysis of ECM remodeling in varicose veins. Decorin is secreted to extracellular region. Correct but less specific than extracellular matrix. Supporting Evidence: PMID:27068509 Extracellular matrix remodelling in response to venous hypertension: proteomics of human varicose veins.
GO:0031012 extracellular matrix	HDA PMID:27559042 Glycoproteomics Reveals Decorin Peptides With Anti-Myostatin...	ACCEPT	Summary: Correct cellular component annotation from HDA glycoproteomics. Decorin is an ECM proteoglycan. Reason: Accurate annotation from glycoproteomics analysis of human atrial fibrillation tissues. Decorin is a core extracellular matrix proteoglycan. Supporting Evidence: PMID:27559042 Glycoproteomics Reveals Decorin Peptides With Anti-Myostatin Activity in Human Atrial Fibrillation.
GO:0005615 extracellular space	HDA PMID:20551380 Proteomics characterization of extracellular space component...	ACCEPT	Summary: Correct cellular component annotation from HDA proteomics of human aorta extracellular space. Decorin is secreted to extracellular space. Reason: Accurate annotation from proteomic characterization of aorta extracellular space components. Decorin functions in extracellular space/ECM. Supporting Evidence: PMID:20551380 Proteomics characterization of extracellular space components in the human aorta.
GO:0031012 extracellular matrix	HDA PMID:20551380 Proteomics characterization of extracellular space component...	ACCEPT	Summary: Correct cellular component annotation from HDA proteomics of human aorta ECM. Decorin is a core ECM proteoglycan. Reason: Accurate annotation from proteomic characterization of human aorta extracellular matrix. Decorin is a fundamental structural component of the ECM. Supporting Evidence: PMID:20551380 Proteomics characterization of extracellular space components in the human aorta.
GO:0031012 extracellular matrix	ISS PMID:22261194 Proteomics analysis of cardiac extracellular matrix remodeli...	ACCEPT	Summary: Correct cellular component annotation from ISS (inferred from sequence similarity) analysis of cardiac ECM. Decorin is an ECM proteoglycan. Reason: Accurate annotation based on sequence similarity inference supported by proteomic analysis of cardiac ECM remodeling. Decorin is a core extracellular matrix component. Supporting Evidence: PMID:22261194 Proteomics analysis of cardiac extracellular matrix remodeling in a porcine model of ischemia/reperfusion injury.
GO:0010596 negative regulation of endothelial cell migration	IDA PMID:23798385 Decorin causes autophagy in endothelial cells via Peg3.	KEEP AS NON CORE	Summary: Decorin suppresses endothelial cell migration via VEGFR2/Peg3/autophagy pathway. This is experimentally demonstrated (IDA). Reason: Well-supported experimental finding from PMID:23798385 showing decorin's anti-angiogenic effects on endothelial cells. However, this is a downstream consequence of decorin's RTK binding activity rather than a core function. Decorin's core functions are collagen fibril organization and TGF-beta sequestration. The endothelial cell effects represent peripheral signaling activities. Marking as non-core. Supporting Evidence: PMID:23798385 Decorin evoked Peg3-dependent autophagy in both microvascular and macrovascular endothelial cells leading to suppression of angiogenesis.
GO:0016525 negative regulation of angiogenesis	IDA PMID:23978385 The paradox of paclitaxel neurotoxicity: Mechanisms and unan...	KEEP AS NON CORE	Summary: Decorin suppresses angiogenesis. Note - PMID:23978385 is about paclitaxel neurotoxicity, likely incorrect PMID. The correct reference should be PMID:23798385 which demonstrates decorin's anti-angiogenic effects. Reason: Anti-angiogenic activity is documented for decorin (should cite PMID:23798385 not PMID:23978385). Decorin binding to VEGFR2 suppresses angiogenesis via autophagy induction. However, this is a secondary signaling function rather than core ECM structural function. Decorin's core functions are collagen organization and TGF-beta sequestration. Marking as non-core. Supporting Evidence: PMID:23798385 Decorin evoked Peg3-dependent autophagy in both microvascular and macrovascular endothelial cells leading to suppression of angiogenesis.
GO:0045944 positive regulation of transcription by RNA polymerase II	IGI PMID:23798385 Decorin causes autophagy in endothelial cells via Peg3.	KEEP AS NON CORE	Summary: Decorin induces transcription of BECN1 and MAPLC3A genes via Peg3. This is demonstrated by genetic interaction studies (IGI). Reason: Experimental finding from PMID:23798385 showing decorin (via Peg3) induces transcription of autophagy genes. This is a downstream signaling consequence in endothelial cells, not a core function. Decorin's core functions are ECM structural roles (collagen organization, TGF-beta sequestration). This transcriptional regulatory activity is a peripheral cell signaling effect. Marking as non-core. Supporting Evidence: PMID:23798385 Decorin, via Peg3, induced transcription of Beclin 1 and microtubule-associated protein 1 light chain 3 alpha genes, thereby leading to a protracted autophagic program.
GO:0051897 positive regulation of phosphatidylinositol 3-kinase/protein kinase B signal transduction	IDA PMID:23798385 Decorin causes autophagy in endothelial cells via Peg3.	KEEP AS NON CORE	Summary: Decorin activates PI3K/AKT signaling in endothelial cells. Demonstrated experimentally (IDA) in context of autophagy induction. Reason: Experimental finding from PMID:23798385 in endothelial cell signaling context. This is a downstream signaling effect, not a core function. Decorin's core functions are ECM structural (collagen organization, TGF-beta sequestration). PI3K/AKT activation is a peripheral cell signaling activity. Marking as non-core. Supporting Evidence: PMID:23798385 decorin, by binding to VEGFR2, triggers a signaling cascade leading to induction of Class III PI3K
GO:0051901 positive regulation of mitochondrial depolarization	IGI PMID:23798385 Decorin causes autophagy in endothelial cells via Peg3.	KEEP AS NON CORE	Summary: Decorin induces loss of mitochondrial membrane potential in endothelial cells via VEGFR2/Peg3 pathway. Genetic interaction evidence (IGI). Reason: Experimental finding from PMID:23798385 showing decorin causes mitochondrial depolarization in endothelial cells as part of autophagy/anti-angiogenic effects. This is a downstream cellular effect, not a core function. Decorin's core functions are ECM structural. Marking as non-core. Supporting Evidence: PMID:23798385 decorin induced VEGFR2-dependent mitochondrial fragmentation and loss of mitochondrial membrane potential
GO:0090141 positive regulation of mitochondrial fission	IGI PMID:23798385 Decorin causes autophagy in endothelial cells via Peg3.	KEEP AS NON CORE	Summary: Decorin induces mitochondrial fragmentation/fission in endothelial cells. Genetic interaction evidence (IGI). Reason: Experimental finding from PMID:23798385 showing decorin causes mitochondrial fission in endothelial cells as part of its anti-angiogenic effects. This is a downstream cellular consequence, not a core function. Decorin's core functions are ECM structural. Marking as non-core. Supporting Evidence: PMID:23798385 decorin induced VEGFR2-dependent mitochondrial fragmentation and loss of mitochondrial membrane potential
GO:1900747 negative regulation of vascular endothelial growth factor signaling pathway	IDA PMID:23798385 Decorin causes autophagy in endothelial cells via Peg3.	KEEP AS NON CORE	Summary: Decorin antagonizes VEGF signaling by binding VEGFR2 and competing with VEGFA. Experimentally demonstrated (IDA). Reason: Well-supported experimental finding from PMID:23798385. Decorin binds VEGFR2 in region overlapping with VEGFA binding site, antagonizing VEGF signaling. However, this is a cell signaling activity rather than decorin's core ECM structural functions (collagen organization, TGF-beta sequestration). Marking as non-core. Supporting Evidence: PMID:23798385 decorin interacted with VEGF receptor 2 (VEGFR2) in a region overlapping with its natural ligand VEGFA
GO:0010508 positive regulation of autophagy	IDA PMID:23798385 Decorin causes autophagy in endothelial cells via Peg3.	KEEP AS NON CORE	Summary: Decorin induces autophagy in endothelial cells. Parent term of GO:0016239 (positive regulation of macroautophagy). Experimentally demonstrated (IDA). Reason: Experimental finding from PMID:23798385 - same biological process as the more specific term GO:0016239 (positive regulation of macroautophagy) already annotated. Decorin induces autophagy via VEGFR2/Peg3 pathway. This is a secondary signaling function, not core ECM structural function. Marking as non-core. Supporting Evidence: PMID:23798385 Decorin evoked Peg3-dependent autophagy in both microvascular and macrovascular endothelial cells leading to suppression of angiogenesis.
GO:0005796 Golgi lumen	TAS Reactome:R-HSA-2022052	KEEP AS NON CORE	Summary: Reactome pathway for conversion of GlcA to IdoA (DSE enzyme) during dermatan sulfate biosynthesis. Decorin transiently in Golgi during GAG modification. Reason: Correct annotation from Reactome dermatan sulfate biosynthesis pathway. DSE converts GlcA to IdoA in decorin's GAG chain in Golgi. Transient biosynthetic localization, not core functional location. Marking as non-core. Supporting Evidence: Reactome:R-HSA-2022052 DSE converts GlcA to IdoA
GO:0005796 Golgi lumen	TAS Reactome:R-HSA-2022063	KEEP AS NON CORE	Summary: Reactome pathway for sulfate transfer by CHST14 to GalNAc in dermatan sulfate. Decorin transiently in Golgi during GAG biosynthesis. Reason: Correct annotation from Reactome dermatan sulfate biosynthesis pathway. CHST14 transfers sulfate to GalNAc residues in decorin's GAG chain in Golgi. Transient biosynthetic localization. Marking as non-core. Supporting Evidence: Reactome:R-HSA-2022063 CHST14 transfers SO4(2-) to GalNAc in dermatan or DS
GO:0005796 Golgi lumen	TAS Reactome:R-HSA-3636919	KEEP AS NON CORE	Summary: Reactome pathway for defective CHST14 (EDS musculocontractural type mutation). Decorin present in Golgi during GAG biosynthesis. Reason: Correct annotation from Reactome disease pathway showing decorin's presence in Golgi during GAG chain modification. Transient biosynthetic localization. Marking as non-core. Supporting Evidence: Reactome:R-HSA-3636919 Defective CHST14 does not transfer SO4(2-) to GalNAc in dermatan or DS
GO:0003723 RNA binding	HDA PMID:22658674 Insights into RNA biology from an atlas of mammalian mRNA-bi...	REMOVE	Summary: Decorin detected in mRNA-binding protein atlas from HDA (high-throughput) study. However, RNA binding is not a characterized molecular function of decorin. Reason: This annotation from PMID:22658674 (mammalian mRNA-binding protein atlas) is likely a false positive from high-throughput screen. Decorin is a secreted extracellular proteoglycan with well-characterized molecular functions (collagen binding, TGF-beta binding, growth factor receptor binding). RNA binding has never been reported as a decorin function in focused studies and makes no biological sense for a secreted ECM protein. Should be removed as over-annotation from HDA screen artifact. Supporting Evidence: PMID:22658674 Insights into RNA biology from an atlas of mammalian mRNA-binding proteins.
GO:0005576 extracellular region	TAS Reactome:R-HSA-2534248	ACCEPT	Summary: Reactome pathway for decorin degradation by MMPs (MMP2, MMP3, MMP7) in extracellular region. Reason: Correct annotation from Reactome ECM degradation pathway. Decorin is degraded by matrix metalloproteinases in the extracellular region where it functions. This confirms decorin's localization to extracellular space. Supporting Evidence: Reactome:R-HSA-2534248 DCN (decorin) degradation by MMP2, MMP3, MMP7
GO:0005576 extracellular region	TAS Reactome:R-HSA-3828025	ACCEPT	Summary: Reactome pathway for decorin degradation by MMP14 in extracellular region. Reason: Correct annotation from Reactome ECM degradation pathway. Decorin is degraded by MMP14 (membrane-type MMP) in the extracellular region. This confirms decorin's extracellular localization. Supporting Evidence: Reactome:R-HSA-3828025 DCN (decorin) degradation by MMP14
GO:0005576 extracellular region	TAS Reactome:R-HSA-2327909	ACCEPT	Summary: Reactome pathway for decorin binding to collagen I, II, III, VI fibrils in extracellular region. Reason: Correct annotation from Reactome collagen binding pathway. This is a core function of decorin - binding to collagen fibrils in the extracellular matrix to regulate fibrillogenesis. Decorin functions in extracellular region/ECM. Supporting Evidence: Reactome:R-HSA-2327909 DCN binds collagen I, II, III, VI fibrils
GO:0005576 extracellular region	TAS Reactome:R-NUL-2466133	ACCEPT	Summary: Reactome pathway for SLRPs binding TGF-beta in extracellular region. Decorin sequesters TGF-beta in ECM. Reason: Correct annotation from Reactome TGF-beta signaling pathway. Decorin binding and sequestering TGF-beta in the extracellular region is one of its core functions. This annotation represents a fundamental aspect of decorin biology. Supporting Evidence: Reactome:R-NUL-2466133 DCN binding is thought to sequester TGF-Beta extracellularly, thereby diminishing its biological activity
GO:0005796 Golgi lumen	TAS Reactome:R-HSA-1878002	KEEP AS NON CORE	Summary: Reactome pathway for xylose transfer to decorin core protein by XYLTs (tetrasaccharide linker biosynthesis). Decorin in Golgi during GAG chain initiation. Reason: Correct annotation from Reactome GAG biosynthesis pathway. XYLTs transfer xylose to Ser-34 of decorin to initiate tetrasaccharide linker formation in Golgi. Transient biosynthetic localization. Marking as non-core. Supporting Evidence: Reactome:R-HSA-1878002 XYLTs transfer Xyl to core protein
GO:0005796 Golgi lumen	TAS Reactome:R-HSA-1889955	KEEP AS NON CORE	Summary: Reactome pathway for GlcA transfer to tetrasaccharide linker by B3GAT dimers. Decorin in Golgi during GAG linker biosynthesis. Reason: Correct annotation from Reactome tetrasaccharide linker biosynthesis pathway. B3GAT transfers GlcA to the linker region of decorin's GAG attachment site in Golgi. Transient biosynthetic localization. Marking as non-core. Supporting Evidence: Reactome:R-HSA-1889955 B3GAT dimers transfer GlcA to tetrasaccharide linker
GO:0005796 Golgi lumen	TAS Reactome:R-HSA-1889978	KEEP AS NON CORE	Summary: Reactome pathway for Gal transfer to tetrasaccharide linker by B3GALT6. Decorin in Golgi during GAG linker assembly. Reason: Correct annotation from Reactome tetrasaccharide linker biosynthesis pathway. B3GALT6 transfers galactose to the linker region in Golgi. Transient biosynthetic localization. Marking as non-core. Supporting Evidence: Reactome:R-HSA-1889978 B3GALT6 transfers Gal to the tetrasaccharide linker
GO:0005796 Golgi lumen	TAS Reactome:R-HSA-1889981	KEEP AS NON CORE	Summary: Reactome pathway for Gal transfer to xylosyl-unit by B4GALT7 (first step of tetrasaccharide linker). Decorin in Golgi during GAG biosynthesis. Reason: Correct annotation from Reactome tetrasaccharide linker biosynthesis pathway. B4GALT7 transfers galactose to xylose on decorin in Golgi. Transient biosynthetic localization. Marking as non-core. Supporting Evidence: Reactome:R-HSA-1889981 B4GALT7 transfers Gal group to xylosyl-unit of the tetrasaccharide linker
GO:0005796 Golgi lumen	TAS Reactome:R-HSA-1971482	KEEP AS NON CORE	Summary: Reactome pathway for GalNAc transfer to CS linker glycan by CSGALNACTs. Decorin in Golgi during chondroitin sulfate biosynthesis. Reason: Correct annotation from Reactome chondroitin sulfate biosynthesis pathway. CSGALNACTs transfer GalNAc to initiate CS chain on decorin in Golgi. Transient biosynthetic localization. Marking as non-core. Supporting Evidence: Reactome:R-HSA-1971482 CSGALNACTs transfer GalNAc to CS linker glycan
GO:0005796 Golgi lumen	TAS Reactome:R-HSA-3560802	KEEP AS NON CORE	Summary: Reactome disease pathway for defective B3GAT3 (JDSSDHD mutation). Decorin present in Golgi during attempted GAG biosynthesis even with defective enzyme. Reason: Correct annotation from Reactome disease pathway. In JDSSDHD (joint dislocations, short stature, craniofacial dysmorphism with or without congenital heart defects), defective B3GAT3 cannot transfer GlcA, but decorin substrates are still present in Golgi. Transient biosynthetic localization. Marking as non-core. Supporting Evidence: Reactome:R-HSA-3560802 Defective B3GAT3 does not transfer GlcA to tetrasaccharide linker
GO:0005796 Golgi lumen	TAS Reactome:R-HSA-3560804	KEEP AS NON CORE	Summary: Reactome disease pathway for defective B4GALT7 (EDS progeroid type mutation). Decorin present in Golgi even with defective GAG biosynthesis enzyme. Reason: Correct annotation from Reactome disease pathway. In EDS progeroid type, defective B4GALT7 cannot transfer Gal to xylose, but decorin is still present in Golgi. Transient biosynthetic localization. Marking as non-core. Supporting Evidence: Reactome:R-HSA-3560804 Defective B4GALT7 does not transfer Gal to xylosyl-unit of the tetrasaccharide linker
GO:0005796 Golgi lumen	TAS Reactome:R-HSA-4420365	KEEP AS NON CORE	Summary: Reactome disease pathway for defective B3GALT6 (EDSP2/SEMDJL1 mutations). Decorin present in Golgi even with defective GAG biosynthesis. Reason: Correct annotation from Reactome disease pathway. In EDSP2 and SEMDJL1, defective B3GALT6 cannot transfer Gal to linker, but decorin is present in Golgi. Transient biosynthetic localization. Marking as non-core. Supporting Evidence: Reactome:R-HSA-4420365 Defective B3GALT6 does not transfer Gal to the tetrasaccharide linker
GO:0043202 lysosomal lumen	TAS Reactome:R-HSA-1793176	KEEP AS NON CORE	Summary: Reactome pathway for dermatan sulfate cleavage from proteoglycan in lysosome during degradation. Decorin eventually degraded in lysosomes. Reason: Correct annotation from Reactome degradation pathway. Decorin (as dermatan sulfate proteoglycan) is eventually internalized and degraded in lysosomes, where DS GAG chains are cleaved. This represents the terminal degradation step, not functional localization. Marking as non-core. Supporting Evidence: Reactome:R-HSA-1793176 DS is cleaved from its proteoglycan
GO:0043202 lysosomal lumen	TAS Reactome:R-HSA-2065233	KEEP AS NON CORE	Summary: Reactome pathway for chondroitin sulfate cleavage from proteoglycan in lysosome during degradation. Decorin eventually degraded in lysosomes. Reason: Correct annotation from Reactome degradation pathway. Decorin (as chondroitin sulfate proteoglycan) is eventually degraded in lysosomes where CS chains are cleaved. Terminal degradation step, not functional localization. Marking as non-core. Supporting Evidence: Reactome:R-HSA-2065233 CS is cleaved from its proteoglycan
GO:0005796 Golgi lumen	TAS Reactome:R-HSA-1971483	KEEP AS NON CORE	Summary: Reactome pathway for sulfate transfer to GalNAc by CHST enzymes during CS/DS biosynthesis. Decorin in Golgi during GAG sulfation. Reason: Correct annotation from Reactome chondroitin/dermatan sulfate biosynthesis pathway. CHST11/12/13/9 transfer sulfate to 4-position of GalNAc in decorin's GAG chain in Golgi. Transient biosynthetic localization. Marking as non-core. Supporting Evidence: Reactome:R-HSA-1971483 CHST11,12,13,9 transfer sulfate to (4-)GalNAc
GO:0005796 Golgi lumen	TAS Reactome:R-HSA-1971487	KEEP AS NON CORE	Summary: Reactome pathway for GalNAc transfer to CS chain by chondroitin polymerase complex. Decorin in Golgi during CS chain elongation. Reason: Correct annotation from Reactome chondroitin sulfate biosynthesis pathway. Chondroitin polymerase complex elongates CS chain on decorin by adding GalNAc residues in Golgi. Transient biosynthetic localization. Marking as non-core. Supporting Evidence: Reactome:R-HSA-1971487 Chondroitin polymerase complex transfers GalNAc to CS chain
GO:0005796 Golgi lumen	TAS Reactome:R-HSA-1971491	KEEP AS NON CORE	Summary: Reactome pathway for GlcA transfer to CS chain by chondroitin polymerase complex. Decorin in Golgi during CS chain elongation. Reason: Correct annotation from Reactome chondroitin sulfate biosynthesis pathway. Chondroitin polymerase complex adds GlcA to decorin's CS chain in Golgi. Transient biosynthetic localization. Marking as non-core. Supporting Evidence: Reactome:R-HSA-1971491 Chondroitin polymerase complex transfers GlcA to CS chain
GO:0005796 Golgi lumen	TAS Reactome:R-HSA-2018659	KEEP AS NON CORE	Summary: Reactome pathway for sulfate transfer by CHST15 to GalNAc-4-sulfate (creating 4,6-disulfated GalNAc). Decorin in Golgi during DS biosynthesis. Reason: Correct annotation from Reactome dermatan sulfate biosynthesis pathway. CHST15 adds additional sulfate to create disulfated GalNAc in decorin's GAG chain in Golgi. Transient biosynthetic localization. Marking as non-core. Supporting Evidence: Reactome:R-HSA-2018659 CHST15 transfers sulfate to (6-)GalNAc-4-sulfate
GO:0005796 Golgi lumen	TAS Reactome:R-HSA-2018682	KEEP AS NON CORE	Summary: Reactome pathway for sulfate transfer to position 6 of GalNAc by CHST3/7. Decorin in Golgi during CS biosynthesis. Reason: Correct annotation from Reactome chondroitin sulfate biosynthesis pathway. CHST3/7 transfer sulfate to 6-position of GalNAc in decorin's GAG chain in Golgi. Transient biosynthetic localization. Marking as non-core. Supporting Evidence: Reactome:R-HSA-2018682 CHST3,7 transfer SO4(2-) to position 6 of GalNAc on chondroitin chains
GO:0005796 Golgi lumen	TAS Reactome:R-HSA-2022061	KEEP AS NON CORE	Summary: Reactome pathway for sulfation of iduronate (position 2) in dermatan sulfate. Decorin in Golgi during DS modification. Reason: Correct annotation from Reactome dermatan sulfate biosynthesis pathway. Additional sulfation of position 2 of iduronate in decorin's DS chain occurs in Golgi. Transient biosynthetic localization. Marking as non-core. Supporting Evidence: Reactome:R-HSA-2022061 Dermatan sulfate can be further sulfated on position 2 of iduronate
GO:0005796 Golgi lumen	TAS Reactome:R-HSA-3595175	KEEP AS NON CORE	Summary: Reactome disease pathway for defective CHST3 (SEDCJD mutation - spondyloepiphyseal dysplasia with congenital joint dislocations). Decorin present in Golgi. Reason: Correct annotation from Reactome disease pathway. In SEDCJD, defective CHST3 cannot transfer sulfate to chondroitin, but decorin substrates are present in Golgi. Transient biosynthetic localization. Marking as non-core. Supporting Evidence: Reactome:R-HSA-3595175 Defective CHST3 does not transfer SO4(2-) to chondroitin
GO:0005796 Golgi lumen	TAS Reactome:R-HSA-3595176	KEEP AS NON CORE	Summary: Reactome disease pathway for defective CHSY1 (TPBS mutation - Temtamy preaxial brachydactyly syndrome). Decorin present in Golgi. Reason: Correct annotation from Reactome disease pathway. In TPBS, defective CHSY1 cannot transfer GalNAc to chondroitin, but decorin is present in Golgi. Transient biosynthetic localization. Marking as non-core. Supporting Evidence: Reactome:R-HSA-3595176 Defective CHSY1 does not transfer GalNAc to chondroitin
GO:0005796 Golgi lumen	TAS Reactome:R-HSA-3595178	KEEP AS NON CORE	Summary: Reactome disease pathway for defective CHSY1 (TPBS mutation). Decorin present in Golgi during defective CS biosynthesis. Reason: Correct annotation from Reactome disease pathway. In TPBS, defective CHSY1 cannot transfer GlcA to chondroitin, but decorin is present in Golgi. Transient biosynthetic localization. Marking as non-core. Supporting Evidence: Reactome:R-HSA-3595178 Defective CHSY1 does not transfer GlcA to chondroitin
GO:0005796 Golgi lumen	TAS Reactome:R-HSA-9632033	KEEP AS NON CORE	Summary: Reactome pathway for GalNAc transfer to CS chain by CSGALNACTs. Decorin in Golgi during CS chain elongation. Reason: Correct annotation from Reactome chondroitin sulfate biosynthesis pathway. CSGALNACTs add GalNAc residues to elongate CS chain on decorin in Golgi. Transient biosynthetic localization. Marking as non-core. Supporting Evidence: Reactome:R-HSA-9632033 CSGALNACTs transfer GalNAc to CS chain
GO:0043202 lysosomal lumen	TAS Reactome:R-HSA-2022056	KEEP AS NON CORE	Summary: Reactome pathway for DSPG/CSPG translocation to lysosome for degradation. Decorin eventually degraded in lysosomal lumen. Reason: Correct annotation from Reactome degradation pathway. Decorin (as dermatan/chondroitin sulfate proteoglycan) is internalized and translocated to lysosomes for degradation. Terminal degradation step, not functional localization. Marking as non-core. Supporting Evidence: Reactome:R-HSA-2022056 DSPG and CSPG translocate to the lysosome for degradation
GO:0009887 animal organ morphogenesis	TAS PMID:7961765 The murine decorin. Complete cDNA cloning, genomic organizat...	KEEP AS NON CORE	Summary: Decorin expression during organogenesis and tissue differentiation in mouse. TAS (traceable author statement) from developmental study. Reason: Correct annotation from PMID:7961765 studying murine decorin expression during development. Decorin is expressed during organ morphogenesis and tissue differentiation. However, this is a developmental/tissue-specific process rather than decorin's core molecular/cellular function. Decorin's core functions are collagen fibril organization and TGF-beta sequestration. Marking as non-core. Supporting Evidence: PMID:7961765 The murine decorin. Complete cDNA cloning, genomic organization, chromosomal assignment, and expression during organogenesis and tissue differentiation.

References

GO_REF:0000024

Manual transfer of experimentally-verified manual GO annotation data to orthologs by curator judgment of sequence similarity.

GO_REF:0000033

Annotation inferences using phylogenetic trees

GO_REF:0000044

Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location vocabulary mapping, accompanied by conservative changes to GO terms applied by UniProt.

GO_REF:0000107

Automatic transfer of experimentally verified manual GO annotation data to orthologs using Ensembl Compara.

PMID:11598131

WISP-1 binds to decorin and biglycan.

PMID:1747115

Interaction of the small proteoglycan decorin with fibronectin. Involvement of the sequence NKISK of the core protein.

PMID:20026052

Decorin is processed by three isoforms of bone morphogenetic protein-1 (BMP1).

PMID:20551380

Proteomics characterization of extracellular space components in the human aorta.

PMID:22261194

Proteomics analysis of cardiac extracellular matrix remodeling in a porcine model of ischemia/reperfusion injury.

PMID:22658674

Insights into RNA biology from an atlas of mammalian mRNA-binding proteins.

PMID:23798385

Decorin causes autophagy in endothelial cells via Peg3.

PMID:23978385

The paradox of paclitaxel neurotoxicity: Mechanisms and unanswered questions.

PMID:25037231

Extracellular matrix signatures of human primary metastatic colon cancers and their metastases to liver.

PMID:25331875

Xylose phosphorylation functions as a molecular switch to regulate proteoglycan biosynthesis.

PMID:25789606

A secretory kinase complex regulates extracellular protein phosphorylation.

PMID:27068509

Extracellular matrix remodelling in response to venous hypertension: proteomics of human varicose veins.

PMID:27559042

Glycoproteomics Reveals Decorin Peptides With Anti-Myostatin Activity in Human Atrial Fibrillation.

PMID:28327460

Comprehensive proteomic characterization of stem cell-derived extracellular matrices.

PMID:28675934

Characterization of the Extracellular Matrix of Normal and Diseased Tissues Using Proteomics.

PMID:7961765

The murine decorin. Complete cDNA cloning, genomic organization, chromosomal assignment, and expression during organogenesis and tissue differentiation.

Reactome:R-HSA-1793176

DS is cleaved from its proteoglycan

Reactome:R-HSA-1878002

XYLTs transfer Xyl to core protein

Reactome:R-HSA-1889955

B3GAT dimers transfer GlcA to tetrasaccharide linker

Reactome:R-HSA-1889978

B3GALT6 transfers Gal to the tetrasaccharide linker

Reactome:R-HSA-1889981

B4GALT7 transfers Gal group to xylosyl-unit of the tetrasaccharide linker

Reactome:R-HSA-1971482

CSGALNACTs transfer GalNAc to CS linker glycan

Reactome:R-HSA-1971483

CHST11,12,13,9 transfer sulfate to (4-)GalNAc

Reactome:R-HSA-1971487

Chondroitin polymerase complex transfers GalNAc to CS chain

Reactome:R-HSA-1971491

Chondroitin polymerase complex transfers GlcA to CS chain

Reactome:R-HSA-2018659

CHST15 transfers sulfate to (6-)GalNAc-4-sulfate

Reactome:R-HSA-2018682

CHST3,7 transfer SO4(2-) to position 6 of GalNAc on chondroitin chains

Reactome:R-HSA-2022052

DSE converts GlcA to IdoA

Reactome:R-HSA-2022056

DSPG and CSPG translocate to the lysosome for degradation

Reactome:R-HSA-2022061

Dermatan sulfate can be further sulfated on position 2 of iduronate

Reactome:R-HSA-2022063

CHST14 transfers SO4(2-) to GalNAc in dermatan or DS

Reactome:R-HSA-2022065

DSPGs are secreted

Reactome:R-HSA-2022911

CSPG is secreted

Reactome:R-HSA-2065233

CS is cleaved from its proteoglycan

Reactome:R-HSA-2327909

DCN binds collagen I, II, III, VI fibrils

Reactome:R-HSA-2534248

DCN (decorin) degradation by MMP2, MMP3, MMP7

Reactome:R-HSA-3560802

Defective B3GAT3 does not transfer GlcA to tetrasaccharide linker

Reactome:R-HSA-3560804

Defective B4GALT7 does not transfer Gal to xylosyl-unit of the tetrasaccharide linker

Reactome:R-HSA-3595175

Defective CHST3 does not transfer SO4(2-) to chondroitin

Reactome:R-HSA-3595176

Defective CHSY1 does not transfer GalNAc to chondroitin

Reactome:R-HSA-3595178

Defective CHSY1 does not transfer GlcA to chondroitin

Reactome:R-HSA-3636919

Defective CHST14 does not transfer SO4(2-) to GalNAc in dermatan or DS

Reactome:R-HSA-3828025

DCN (decorin) degradation by MMP14

Reactome:R-HSA-4420365

Defective B3GALT6 does not transfer Gal to the tetrasaccharide linker

Reactome:R-HSA-9632033

CSGALNACTs transfer GalNAc to CS chain

Reactome:R-HSA-9940993

PXYLP1 dephosphorylates Xyl moiety

Reactome:R-HSA-9941039

FAM20B phosphorylates Xyl moiety

Reactome:R-HSA-9941305

UST transfers sulfate to (2-)GlcA-GalNAc-6-sulfate

Reactome:R-HSA-9941312

CHST15 transfers sulfate to (6-)GalNAc-4-sulfate

Reactome:R-NUL-2466133

SLRPs bind TGF beta

file:human/DCN/DCN-deep-research-falcon.md

Deep research report on DCN

📚 Additional Documentation

Deep Research Falcon

(DCN-deep-research-falcon.md)

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gene_id: DCN
gene_symbol: DCN
uniprot_accession: P07585
protein_description: 'RecName: Full=Decorin; AltName: Full=Bone proteoglycan II;
AltName: Full=PG-S2; AltName: Full=PG40; Flags: Precursor;'
gene_info: Name=DCN; Synonyms=SLRR1B;
organism_full: Homo sapiens (Human).
protein_family: Belongs to the small leucine-rich proteoglycan (SLRP)
protein_domains: Leu-rich_rpt. (IPR001611); Leu-rich_rpt_typical-subtyp. (IPR003591);
LRR_dom_sf. (IPR032675); LRRNT. (IPR000372); SLRP. (IPR050333)
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Question

Gene Research for Functional Annotation

⚠️ CRITICAL: Gene/Protein Identification Context

BEFORE YOU BEGIN RESEARCH: You MUST verify you are researching the CORRECT gene/protein. Gene symbols can be ambiguous, especially for less well-characterized genes from non-model organisms.

Target Gene/Protein Identity (from UniProt):

UniProt Accession: P07585
Protein Description: RecName: Full=Decorin; AltName: Full=Bone proteoglycan II; AltName: Full=PG-S2; AltName: Full=PG40; Flags: Precursor;
Gene Information: Name=DCN; Synonyms=SLRR1B;
Organism (full): Homo sapiens (Human).
Protein Family: Belongs to the small leucine-rich proteoglycan (SLRP)
Key Domains: Leu-rich_rpt. (IPR001611); Leu-rich_rpt_typical-subtyp. (IPR003591); LRR_dom_sf. (IPR032675); LRRNT. (IPR000372); SLRP. (IPR050333)

MANDATORY VERIFICATION STEPS:

Check if the gene symbol "DCN" matches the protein description above
Verify the organism is correct: Homo sapiens (Human).
Check if protein family/domains align with what you find in literature
If you find literature for a DIFFERENT gene with the same or similar symbol, STOP

If Gene Symbol is Ambiguous or You Cannot Find Relevant Literature:

DO NOT PROCEED WITH RESEARCH ON A DIFFERENT GENE. Instead:
- State clearly: "The gene symbol 'DCN' is ambiguous or literature is limited for this specific protein"
- Explain what you found (e.g., "Found extensive literature on a different gene with the same symbol in a different organism")
- Describe the protein based ONLY on the UniProt information provided above
- Suggest that the protein function can be inferred from domain/family information

Research Target:

Please provide a comprehensive research report on the gene DCN (gene ID: DCN, UniProt: P07585) in human.

The research report should be a detailed narrative explaining the function, biological processes, and localization of the gene product. Citations should be given for all claims.

You should prioritize authoritative reviews and primary scientific literature when conducting research. You can supplement
this with annotations you find in gene/protein databases, but these can be outdated or inaccurate.

We are specifically interested in the primary function of the gene - for enzymes, what reaction is catalyzed, and what is the substrate specificity? For transporters, what is the substrate? For structural proteins or adapters, what is the broader structural role? For signaling molecules, what is the role in the pathway.

We are interested in where in or outside the cell the gene product carries out its function.

We are also interested in the signaling or biochemical pathways in which the gene functions. We are less interested in broad pleiotropic effects, except where these elucidate the precise role.

Include evidence where possible. We are interested in both experimental evidence as well as inference from structure, evolution, or bioinformatic analysis. Precise studies should be prioritized over high-throughput, where available.

Output

Question: You are an expert researcher providing comprehensive, well-cited information.

Provide detailed information focusing on:
1. Key concepts and definitions with current understanding
2. Recent developments and latest research (prioritize 2023-2024 sources)
3. Current applications and real-world implementations
4. Expert opinions and analysis from authoritative sources
5. Relevant statistics and data from recent studies

Format as a comprehensive research report with proper citations. Include URLs and publication dates where available.
Always prioritize recent, authoritative sources and provide specific citations for all major claims.

Gene Research for Functional Annotation

⚠️ CRITICAL: Gene/Protein Identification Context

BEFORE YOU BEGIN RESEARCH: You MUST verify you are researching the CORRECT gene/protein. Gene symbols can be ambiguous, especially for less well-characterized genes from non-model organisms.

Target Gene/Protein Identity (from UniProt):

UniProt Accession: P07585
Protein Description: RecName: Full=Decorin; AltName: Full=Bone proteoglycan II; AltName: Full=PG-S2; AltName: Full=PG40; Flags: Precursor;
Gene Information: Name=DCN; Synonyms=SLRR1B;
Organism (full): Homo sapiens (Human).
Protein Family: Belongs to the small leucine-rich proteoglycan (SLRP)
Key Domains: Leu-rich_rpt. (IPR001611); Leu-rich_rpt_typical-subtyp. (IPR003591); LRR_dom_sf. (IPR032675); LRRNT. (IPR000372); SLRP. (IPR050333)

MANDATORY VERIFICATION STEPS:

Check if the gene symbol "DCN" matches the protein description above
Verify the organism is correct: Homo sapiens (Human).
Check if protein family/domains align with what you find in literature
If you find literature for a DIFFERENT gene with the same or similar symbol, STOP

If Gene Symbol is Ambiguous or You Cannot Find Relevant Literature:

Research Target:

Please provide a comprehensive research report on the gene DCN (gene ID: DCN, UniProt: P07585) in human.

The research report should be a detailed narrative explaining the function, biological processes, and localization of the gene product. Citations should be given for all claims.

We are interested in where in or outside the cell the gene product carries out its function.

We are also interested in the signaling or biochemical pathways in which the gene functions. We are less interested in broad pleiotropic effects, except where these elucidate the precise role.

Plan status and verification
We verified the target gene/protein identity. DCN encodes human decorin (UniProt P07585), a class I small leucine‑rich proteoglycan (SLRP) bearing an N‑terminal dermatan/chondroitin sulfate glycosaminoglycan (GAG) chain on a leucine‑rich repeat (LRR) core; it localizes to the extracellular matrix (ECM) and pericellular space. This aligns with recent reviews and primary literature focused on human tissues and disease contexts (mondal2024decorinsuppressestumor pages 1-2, patel2020decorinexpressionis pages 12-13).

Comprehensive research report

1) Key concepts and definitions
- Identity and structure: Decorin is a secreted ECM proteoglycan with a ~40 kDa core protein comprising an N‑terminal signal and pro‑peptide, a cysteine‑rich N terminus carrying a single GAG chain (usually dermatan sulfate, sometimes chondroitin sulfate), 10–12 central LRRs that mediate ligand binding, and a C‑terminal cysteine‑containing region; it can exist in ECM as a soluble or matrix‑bound species (frejborg2025decorinexpressingoncolyticherpes pages 30-34, rao2025researchprogresson pages 1-2). Functionally, decorin is an archetypal SLRP that regulates matrix assembly, growth factor bioavailability, and receptor tyrosine kinase (RTK) signaling (frejborg2025decorinexpressingoncolyticherpes pages 30-34, rao2025researchprogresson pages 1-2).
- Localization: Decorin is synthesized by stromal/mesenchymal cells and deposited in interstitial ECM, with prominent localization around collagen fibrils and in vascular/perivascular niches in tumors (patel2020decorinexpressionis pages 12-13, frejborg2025decorinexpressingoncolyticherpes pages 30-34). In glioblastoma, decorin mRNA and protein localize to regions of microvascular proliferation and the tunica adventitia, consistent with perivascular ECM roles (patel2020decorinexpressionis pages 12-13).
- Core functions: (i) Collagen binding and fibrillogenesis control; (ii) sequestration/neutralization of TGF‑β to tune fibrogenic signaling; (iii) direct modulation of RTKs including EGFR, MET, and VEGFR family members, conferring anti‑tumor, anti‑angiogenic, and anti‑lymphangiogenic actions (mondal2024decorinsuppressestumor pages 1-2, patel2020decorinexpressionis pages 12-13, frejborg2025decorinexpressingoncolyticherpes pages 30-34).

2) Recent developments and latest research (2023–2024 prioritized)
- Antilymphangiogenic mechanism via VEGFR3: A 2024 PNAS study demonstrated that recombinant decorin suppresses tumor lymphangiogenesis by down‑regulating VEGFR3 signaling and evoking autophagic degradation of the lymphatic marker LYVE1; decorin acts as an extracellular ligand/modulator for multiple RTKs (EGFR, MET, VEGFR2) and additionally targets VEGFR3 (new mechanistic addition) (Mondal 2024; Apr 2024; https://doi.org/10.1073/pnas.2317760121) (mondal2024decorinsuppressestumor pages 1-2).
- Corneal dystrophy classification update: The 2024 IC3D third edition confirms DCN among stromal dystrophy genes underlying congenital stromal corneal dystrophy (CSCD), integrating recent genetic and clinicopathologic evidence (Feb 2024; https://doi.org/10.1097/ico.0000000000003420) (IC3D) (Referenced in table).
- Human DCN variant in CSCD: A 2023 report identified a novel de novo frameshift in DCN (NM_001920.5:c.953del; p.Asn318Thrfs*10) in a pediatric CSCD case with bilateral stromal opacity, strengthening DCN causality in human corneal stromal organization (Mar 2023; https://doi.org/10.1038/s41439-023-00239-8) (Morikawa 2023) (Referenced in table).
- Fibrosis biomarker development: In MASLD, a serum panel incorporating decorin (with GDF15 and clinical variables) predicted hepatic fibrosis with AUROC 0.912 (development cohort, n=144) and 0.977 (biopsy‑validated external cohort, n=41), indicating clinical utility of circulating decorin as part of a composite fibrosis index (Nov 2024; https://doi.org/10.1038/s41598-024-77719-6) (Chang 2024) (Referenced in table).
- ECM assembly perspective: A 2024 Nature Reviews article on ECM mechanisms details SLRP roles (including decorin) in collagen fibrillogenesis and growth‑factor sequestration, integrating structural–functional knowledge central to DCN biology (Sep 2024; https://doi.org/10.1038/s41580-024-00767-3) (Referenced in table).
- TGF‑β signaling nexus: A 2024 translational review highlights TGF‑β’s centrality in fibrosis and cancer and recognizes decorin’s capacity to sequester TGF‑β and induce p21, contextualizing DCN within anti‑fibrotic and tumor‑suppressive signaling networks (Jun 2024; https://doi.org/10.1186/s12967-024-05411-4) (Referenced in table).
- Ocular neovascularization therapeutics: A 2024 review lists decorin among anti‑fibrotic options to mitigate corneal scarring and pathological angiogenesis by TGF‑β sequestration, aligning with its anti‑angiogenic RTK‑modulatory profile (May 2024; https://doi.org/10.3390/ijms25105479) (Referenced in table).

3) Primary molecular functions and pathways
- Collagen fibrillogenesis and matrix organization: Decorin binds fibrillar collagens (types I/III/V) at periodic sites, regulates fibril diameter/spacing, and contributes to tissue tensile properties; these structural roles underpin corneal transparency and tendon/skin mechanics (frejborg2025decorinexpressingoncolyticherpes pages 30-34). The ECM assembly review synthesizes SLRP participation in these processes (2024) (Referenced in table).
- TGF‑β sequestration and anti‑fibrotic signaling: Decorin binds TGF‑β isoforms in the ECM, limiting receptor engagement and downstream profibrotic SMAD signaling; this mechanism is repeatedly implicated in anti‑fibrotic activity in multiple tissues and in therapeutic proposals (frejborg2025decorinexpressingoncolyticherpes pages 30-34). Contemporary reviews (2024) emphasize decorin as an ECM checkpoint for TGF‑β bioavailability (Referenced in table).
- RTK modulation and downstream signaling: Decorin directly interacts with and modulates RTKs, including EGFR and MET, leading to receptor down‑regulation, p21 induction, apoptosis, and suppression of pro‑oncogenic pathways (patel2020decorinexpressionis pages 12-13, frejborg2025decorinexpressingoncolyticherpes pages 30-34). It also antagonizes VEGFR2 signaling to inhibit angiogenesis, and, critically, 2024 work extends this to VEGFR3, linking decorin to antilymphangiogenic programs via suppression of lymphatic gene clusters and Lyve1 degradation (mondal2024decorinsuppressestumor pages 1-2). Collectively, decorin acts as a pan‑RTK extracellular modulator shaping tumor, angiogenic, and stromal responses (mondal2024decorinsuppressestumor pages 1-2, patel2020decorinexpressionis pages 12-13).

4) Disease relevance and human genetics
- Corneal stromal dystrophy (CSCD): Pathogenic DCN variants cause autosomal dominant CSCD with diffuse stromal opacity, consistent with decorin’s essential role in corneal collagen lamellae organization; the 2023 pediatric case (c.953del) provides direct human genetic evidence, and the 2024 IC3D classification recognizes DCN in stromal dystrophies (Morikawa 2023; IC3D 2024) (Referenced in table).
- Cancer biology: Decorin often exhibits oncosuppressive roles. In glioblastoma, higher decorin expression is observed in perivascular niches and correlates with MRI diffusion phenotypes linked to improved benefit from anti‑VEGF therapy; DCN expression colocalizes with VEGFR1/2, aligning with its anti‑angiogenic positioning (Sep 2020; human cohorts, imaging–molecular correlations) (patel2020decorinexpressionis pages 12-13). In 2024, systemic decorin delivery curtailed breast tumor lymphangiogenesis via VEGFR3, providing a mechanistic basis for anti‑metastatic potential through lymphatic suppression (mondal2024decorinsuppressestumor pages 1-2).
- Fibrosis and organ remodeling: By neutralizing TGF‑β and modulating ECM assembly, decorin is positioned as an anti‑fibrotic agent. Clinically oriented evidence in MASLD shows circulating decorin contributes to a high‑performance panel predicting hepatic fibrosis severity (AUROC up to 0.977), supporting translational relevance as a systemic biomarker (Chang 2024) (Referenced in table).

5) Quantitative and localization data (selected recent metrics)
- MASLD fibrosis prediction: Serum panel including decorin (MSI‑F) achieved AUROC 0.912 in a population‑based development cohort (n=144) and 0.977 in a biopsy‑validated external cohort (n=41), with diagnostic accuracy 82.6–92.4% (Nov 2024; Scientific Reports) (Referenced in table).
- GBM imaging–molecular correlations: High ADCL tumors showed markedly higher DCN RNA (41.6 vs 1.5; P=0.0081), and DCN protein correlated with ADCL across and within tumors (Pearson R² ≈ 0.30–0.40), with spatial localization to microvascular proliferation and vessel adventitia (Sep 2020; Scientific Reports) (patel2020decorinexpressionis pages 12-13).
- Lymphangiogenesis suppression: Mondal 2024 reports reduction of lymphatic gene signatures (Lyve1, Podoplanin) and functional suppression of ex vivo lymphatic sprouting upon decorin treatment, mechanistically linked to VEGFR3 down‑regulation and Lyve1 autophagic degradation (Apr 2024; PNAS) (mondal2024decorinsuppressestumor pages 1-2).

6) Current applications and implementations
- Biomarkers: Emerging evidence positions circulating decorin as a component of multi‑analyte panels for fibrosis (MASLD), with externally validated performance (Chang 2024) (Referenced in table).
- Therapeutic concepts: Preclinical work supports recombinant decorin or vector‑delivered decorin to suppress angiogenesis/lymphangiogenesis and fibrotic remodeling via TGF‑β sequestration and RTK modulation; ocular surface and corneal neovascularization reviews identify decorin among anti‑fibrotic, anti‑angiogenic candidates (2024) (Referenced in table). While clinical trials specifically administering decorin remain limited, these converging data underscore translational potential.

Expert analysis and synthesis
Decorin’s core biology—ECM localization, LRR‑mediated binding to collagens and growth factors, and modulation of RTKs—provides a coherent mechanistic basis for its roles in tissue architecture, fibrotic signaling control, and tumor/vascular microenvironment regulation. The 2024 PNAS study extends the RTK paradigm to VEGFR3 and lymphatic biology, suggesting decorin shapes not only angiogenesis but also lymphangiogenesis, with implications for metastasis control. Concurrently, human genetic evidence for DCN in CSCD reinforces decorin’s necessity for collagen lamellar order in the cornea. Translationally, the high AUROC values achieved when decorin is combined with stress biomarkers (GDF15) in MASLD highlight its promise as part of non‑invasive fibrosis diagnostics. Together, these lines of evidence establish decorin as a matrix‑embedded signaling hub and structural organizer with growing clinical relevance (mondal2024decorinsuppressestumor pages 1-2, patel2020decorinexpressionis pages 12-13).

Embedded summary table of recent sources
| Year | Study / Source | Focus | Key finding(s) about decorin | Model / Population | Quant / Stats | Link (URL) |
|---|---|---|---|---|---|---|
| 2024 | Mondal et al., PNAS | Tumor lymphangiogenesis / RTK modulation | Decorin suppresses tumor lymphangiogenesis via interaction with VEGFR3 and induces autophagic degradation of Lyve1; acts as extracellular ligand/modulator of multiple RTKs (EGFR, MET, VEGFRs). (mondal2024decorinsuppressestumor pages 1-2) | Breast carcinoma allograft models, ex vivo lymphatic sprouting | Reduced lymphatic gene cluster (Lyve1, Podoplanin); functional suppression of lymphatic sprouting | https://doi.org/10.1073/pnas.2317760121 |
| 2024 | Weiss et al., IC3D (Cornea) | Corneal dystrophy classification / genetics | DCN (decorin) listed among stromal dystrophy genes implicated in congenital stromal corneal dystrophy (CSCD); clinical classification update | Clinical/genetic review of corneal dystrophies | N/A (classification/resource) | https://doi.org/10.1097/ico.0000000000003420 |
| 2023 | Morikawa et al., Human Genome Variation | Genetics — congenital stromal corneal dystrophy | Reported novel de novo DCN frameshift variant c.953del (p.Asn318Thrfs*10) causing pediatric CSCD | Single pediatric case (1-year-old girl) with bilateral stromal opacity | Genetic variant: NM_001920.5:c.953del; clinical corneal phenotype | https://doi.org/10.1038/s41439-023-00239-8 |
| 2024 | Chang et al., Scientific Reports | Biomarker — fibrosis (MASLD) | Serum decorin (with GDF15) predicts fibrotic progression in MASLD; included in MSI-F panel with high diagnostic performance | Human cohorts: development (n=144) and biopsy-validated external (n=41) | MSI-F AUROC = 0.912 (dev), 0.977 (validation); diagnostic accuracy 82.6–92.4% | https://doi.org/10.1038/s41598-024-77719-6 |
| 2024 | Naba, Nat Rev Mol Cell Biol | ECM assembly review | Authoritative review of ECM assembly/remodeling that highlights SLRPs (including decorin) roles in collagen fibrillogenesis and growth-factor sequestration | Broad mechanistic review (mammalian ECM) | N/A (review synthesis) | https://doi.org/10.1038/s41580-024-00767-3 |
| 2024 | Giarratana et al., J Transl Med | TGF-β signaling nexus (fibrosis & cancer) | Reviews TGF-β as central in fibrogenesis/cancer and notes decorin's ability to sequester TGF-β and induce p21-mediated effects that modulate fibrotic/cell-cycle responses | Mechanistic/therapeutic review | N/A (review) | https://doi.org/10.1186/s12967-024-05411-4 |
| 2024 | Drzyzga et al., IJMS | Corneal neovascularization therapies | Reviews therapeutic options for corneal neovascularization and includes decorin as an anti-fibrotic/TGF-β-sequestering candidate to mitigate fibrosis and angiogenesis | Clinical/therapeutic review | N/A (review) | https://doi.org/10.3390/ijms25105479 |
| 2024 | Onubogu et al., JCI Insight | GBM perivascular niche / spatial TME analysis | Spatial analysis localizes ECM texture and implicates decorin-related signaling in perivascular niche organization and interactions with endothelial/perivascular fibroblast compartments | Human primary & recurrent GBM archival tissues (spatial transcriptomics/imaging) | ECM texture predictive of genetic traits; decorin linked to vascular/VEGF-related niches | https://doi.org/10.1172/jci.insight.179853 |
| 2020 | Patel et al., Scientific Reports | Imaging–molecular correlation (anti-VEGF response) | Decorin expression correlates with diffusion MRI phenotypes that predict anti-VEGF efficacy in glioblastoma; DCN localized to microvascular proliferation regions. (patel2020decorinexpressionis pages 12-13) | Human GBM surgical specimens and TCGA/IVY GAP analyses; targeted biopsies (n=35 / 17 in cohorts) | Higher DCN RNA in high ADCL tumors (41.6 vs 1.5; P=0.0081); positive correlation ADCL vs DCN protein (Pearson R^2≈0.30–0.40) | https://doi.org/10.1038/s41598-020-71799-w |

Table: Concise table (2023–2024 prioritized, plus one 2020 baseline study) summarizing human-relevant findings on decorin (DCN): functions, models, and quantitative metrics where reported; useful as a quick reference to primary sources and translational evidence.

References (with URLs and dates)
- Mondal DK et al. Decorin suppresses tumor lymphangiogenesis. Proceedings of the National Academy of Sciences of the USA. Apr 2024. URL: https://doi.org/10.1073/pnas.2317760121 (mondal2024decorinsuppressestumor pages 1-2)
- Patel KS et al. Decorin expression correlates with diffusion MRI phenotypes and anti‑VEGF efficacy in glioblastoma. Scientific Reports. Sep 2020. URL: https://doi.org/10.1038/s41598-020-71799-w (patel2020decorinexpressionis pages 12-13)
- IC3D Committee (Weiss JS et al.). IC3D Classification of Corneal Dystrophies—Edition 3. Cornea. Feb 2024. URL: https://doi.org/10.1097/ico.0000000000003420 (Referenced in table)
- Morikawa H et al. Pediatric CSCD with novel DCN variant c.953del. Human Genome Variation. Mar 2023. URL: https://doi.org/10.1038/s41439-023-00239-8 (Referenced in table)
- Chang JS et al. GDF15 and decorin predict fibrotic progression in MASLD. Scientific Reports. Nov 2024. URL: https://doi.org/10.1038/s41598-024-77719-6 (Referenced in table)
- Naba A. Mechanisms of ECM assembly and remodeling. Nature Reviews Molecular Cell Biology. Sep 2024. URL: https://doi.org/10.1038/s41580-024-00767-3 (Referenced in table)
- Giarratana AO et al. TGF‑β signaling at the nexus of fibrogenesis and cancer. Journal of Translational Medicine. Jun 2024. URL: https://doi.org/10.1186/s12967-024-05411-4 (Referenced in table)
- Drzyzga Ł et al. Therapeutic options for corneal neovascularization. International Journal of Molecular Sciences. May 2024. URL: https://doi.org/10.3390/ijms25105479 (Referenced in table)

Notes and limitations
Where indicated, some foundational mechanistic details (e.g., precise LRR mapping for ligand contacts, broad collagen binding) derive from prior experimental work consolidated in reviews and are consistent with recent summaries; the 2024–2023 human‑focused studies provide updated genetics (CSCD), tumor lymphangiogenesis mechanisms, and clinical biomarker performance. Further quantitative binding constants and site‑specific interaction maps were beyond the present sources and may require additional targeted structural studies.

References

(mondal2024decorinsuppressestumor pages 1-2): Dipon K. Mondal, Christopher Xie, Gabriel J. Pascal, Simone Buraschi, and Renato V. Iozzo. Decorin suppresses tumor lymphangiogenesis: a mechanism to curtail cancer progression. Proceedings of the National Academy of Sciences of the United States of America, Apr 2024. URL: https://doi.org/10.1073/pnas.2317760121, doi:10.1073/pnas.2317760121. This article has 18 citations and is from a highest quality peer-reviewed journal.
(patel2020decorinexpressionis pages 12-13): Kunal S. Patel, Jingwen Yao, Catalina Raymond, William Yong, Richard Everson, Linda M. Liau, David Nathanson, Harley Kornblum, Chencai Wang, Talia Oughourlian, Albert Lai, Phioanh L. Nghiemphu, Whitney B. Pope, Timothy F. Cloughesy, and Benjamin M. Ellingson. Decorin expression is associated with predictive diffusion mr phenotypes of anti-vegf efficacy in glioblastoma. Scientific Reports, Sep 2020. URL: https://doi.org/10.1038/s41598-020-71799-w, doi:10.1038/s41598-020-71799-w. This article has 21 citations and is from a peer-reviewed journal.
(frejborg2025decorinexpressingoncolyticherpes pages 30-34): F Frejborg. Decorin-expressing oncolytic herpes simplex virus vector for novel cancer therapy. Unknown journal, 2025.
(rao2025researchprogresson pages 1-2): YONG RAO, KAIYU LI, MINHAI NIE, XUQIAN LIU, and XIAO CHEN. Research progress on the role of decorin in the development of oral mucosal carcinogenesis. Oncology Research, 33:577-590, Feb 2025. URL: https://doi.org/10.32604/or.2024.053119, doi:10.32604/or.2024.053119. This article has 0 citations and is from a peer-reviewed journal.

Citations

patel2020decorinexpressionis pages 12-13
mondal2024decorinsuppressestumor pages 1-2
frejborg2025decorinexpressingoncolyticherpes pages 30-34
rao2025researchprogresson pages 1-2
https://doi.org/10.1073/pnas.2317760121
https://doi.org/10.1097/ico.0000000000003420
https://doi.org/10.1038/s41439-023-00239-8
https://doi.org/10.1038/s41598-024-77719-6
https://doi.org/10.1038/s41580-024-00767-3
https://doi.org/10.1186/s12967-024-05411-4
https://doi.org/10.3390/ijms25105479
https://doi.org/10.1172/jci.insight.179853
https://doi.org/10.1038/s41598-020-71799-w
https://doi.org/10.1073/pnas.2317760121,
https://doi.org/10.1038/s41598-020-71799-w,
https://doi.org/10.32604/or.2024.053119,

📄 View Raw YAML

id: P07585
gene_symbol: DCN
product_type: PROTEIN
status: COMPLETE
taxon:
  id: NCBITaxon:9606
  label: Homo sapiens
description: 'Decorin is a small leucine-rich proteoglycan (SLRP, 359 amino acids)
  consisting of a core protein (~40 kDa) with 12 leucine-rich repeats and a single
  attached chondroitin sulfate or dermatan sulfate glycosaminoglycan chain at Ser-34.
  Decorin plays two critical core functions in the extracellular matrix: (1) regulation
  of collagen fibrillogenesis, where it binds to collagen types I, II, III, and VI
  fibrils via its LRR domain to control fibril diameter, spacing, and assembly kinetics,
  and (2) sequestration and negative regulation of TGF-beta signaling, where it binds
  all three TGF-beta isoforms in the ECM to diminish their biological activity and
  exert anti-fibrotic effects. Additionally, decorin binds and modulates receptor
  tyrosine kinases including EGFR, VEGFR2, and Met, triggering receptor internalization,
  autophagy induction in endothelial cells via Peg3, and suppression of angiogenesis.
  Decorin also binds fibronectin, thrombospondin-1, and other ECM components. The
  protein is secreted and localized to the extracellular matrix, with transient presence
  in Golgi lumen during biosynthesis and GAG chain modification. Decorin deficiency
  causes congenital stromal corneal dystrophy (CSCD), highlighting its essential role
  in collagen organization and tissue architecture.'
existing_annotations:
  - term:
      id: GO:0005615
      label: extracellular space
    evidence_type: IBA
    original_reference_id: GO_REF:0000033
    review:
      summary: Decorin is a secreted extracellular matrix proteoglycan. IBA 
        annotation based on phylogenetic inference correctly captures decorin's 
        localization to extracellular space where it performs its core functions
        in collagen fibril organization and TGF-beta sequestration.
      action: ACCEPT
      reason: This is a core cellular component annotation supported by 
        extensive experimental evidence (UniProt CC line "Secreted, 
        extracellular space, extracellular matrix"), IBA phylogenetic inference,
        and multiple proteomic studies. Decorin functions exclusively in the 
        extracellular space.
      supported_by:
        - reference_id: GO_REF:0000033
          supporting_text: "IBA annotation inferences using phylogenetic trees"
        - reference_id: Reactome:R-HSA-2327909
          supporting_text: "DCN consists of a core protein of approximately 40 kDa
            attached to a single chondroitin or dermatan sulfate glycosaminoglycan
            (GAG) chain."
        - reference_id: file:human/DCN/DCN-deep-research-falcon.md
          supporting_text: 'model: Edison Scientific Literature'
  - term:
      id: GO:0005576
      label: extracellular region
    evidence_type: IEA
    original_reference_id: GO_REF:0000044
    review:
      summary: Broad parent term of extracellular space. While correct, this is 
        less specific than the IBA annotation to extracellular space 
        (GO:0005615) and extracellular matrix (GO:0031012).
      action: ACCEPT
      reason: Correct but general IEA annotation based on UniProt subcellular 
        location vocabulary. The more specific child terms (extracellular space,
        extracellular matrix) better capture decorin's precise localization, but
        this parent term is not incorrect.
      supported_by:
        - reference_id: GO_REF:0000044
          supporting_text: "Gene Ontology annotation based on UniProtKB/Swiss-Prot
            Subcellular Location vocabulary mapping"
  - term:
      id: GO:0005539
      label: glycosaminoglycan binding
    evidence_type: IEA
    original_reference_id: GO_REF:0000107
    review:
      summary: Decorin itself is a proteoglycan containing a GAG chain, and may 
        have self-association properties. However, the primary molecular 
        function is collagen binding and TGF-beta binding rather than GAG 
        binding per se.
      action: MARK_AS_OVER_ANNOTATED
      reason: While decorin has a GAG chain (dermatan/chondroitin sulfate) 
        attached, GAG binding is not a prominently reported molecular function. 
        The annotation likely derives from domain-based inference (IEA from 
        Ensembl) but decorin's core functions are collagen binding and growth 
        factor binding, not GAG binding. May reflect some self-association or 
        interaction with other proteoglycans, but this is not well-documented as
        a primary function.
      supported_by:
        - reference_id: GO_REF:0000107
          supporting_text: "Automatic transfer of experimentally verified manual GO
            annotation data to orthologs using Ensembl Compara"
  - term:
      id: GO:0050840
      label: extracellular matrix binding
    evidence_type: IEA
    original_reference_id: GO_REF:0000107
    review:
      summary: Too vague. Decorin specifically binds collagen fibrils (types I, 
        II, III, VI), fibronectin, and thrombospondin-1. The more specific 
        molecular function terms should be used.
      action: MODIFY
      reason: This broad term does not capture decorin's specific binding 
        activities. Decorin has well-characterized binding to specific ECM 
        components via its leucine-rich repeats. Should be replaced with more 
        specific molecular function terms for collagen binding and fibronectin 
        binding.
      proposed_replacement_terms:
        - id: GO:0005518
          label: collagen binding
        - id: GO:0001968
          label: fibronectin binding
      supported_by:
        - reference_id: Reactome:R-HSA-2327909
          supporting_text: "It interacts with collagen types I, II (Vogel et al. 1984),
            III (Witos et al. 2011), V (Whinna et al. 1993), VI (Bidanset et al. 1992)
            and XIV (Ehnis et al. 1997)."
        - reference_id: PMID:1747115
          supporting_text: "Decorin, an interstitial small proteoglycan, was shown
            to interact with fibronectin via its core protein. In a solid-phase assay,
            both high-affinity (KD values between 10 and 20 nM) and low-affinity (KD
            values between 110 and 130 nM) binding sites were found."
  - term:
      id: GO:0005515
      label: protein binding
    evidence_type: IPI
    original_reference_id: PMID:1747115
    review:
      summary: Vague term. PMID:1747115 specifically demonstrates fibronectin 
        binding with measured KD values (10-20 nM high affinity, 110-130 nM low 
        affinity). The specific molecular function term should be used instead.
      action: MODIFY
      reason: The term "protein binding" is uninformative per curation 
        guidelines. The cited paper demonstrates specific fibronectin binding 
        via decorin's core protein LRR domain. This should be annotated with the
        specific molecular function GO:0001968 (fibronectin binding).
      proposed_replacement_terms:
        - id: GO:0001968
          label: fibronectin binding
      supported_by:
        - reference_id: PMID:1747115
          supporting_text: "Decorin, an interstitial small proteoglycan, was shown
            to interact with fibronectin via its core protein."
  - term:
      id: GO:0005515
      label: protein binding
    evidence_type: IPI
    original_reference_id: PMID:20026052
    review:
      summary: Vague term. Paper describes decorin processing by bone 
        morphogenetic protein-1 (BMP1) isoforms. This is substrate-enzyme 
        interaction, not a molecular function annotation for decorin itself.
      action: REMOVE
      reason: The term "protein binding" is uninformative per curation 
        guidelines. PMID:20026052 demonstrates that decorin is processed/cleaved
        by BMP1, which is relevant for decorin maturation but does not represent
        a molecular function of decorin. Being a substrate for proteolytic 
        processing is not appropriately annotated as "protein binding."
      supported_by:
        - reference_id: PMID:20026052
          supporting_text: "Decorin is processed by three isoforms of bone morphogenetic
            protein-1 (BMP1)."
  - term:
      id: GO:0005515
      label: protein binding
    evidence_type: IPI
    original_reference_id: PMID:25331875
    review:
      summary: Vague term. Paper concerns xylose phosphorylation regulation of 
        proteoglycan biosynthesis. This is about decorin biosynthesis machinery,
        not decorin's molecular function.
      action: REMOVE
      reason: The term "protein binding" is uninformative per curation 
        guidelines. PMID:25331875 discusses xylose phosphorylation as a 
        regulatory switch in proteoglycan biosynthesis. This interaction is part
        of decorin's biosynthesis pathway, not a functional molecular activity 
        of the mature decorin protein. Should not be annotated as "protein 
        binding."
      supported_by:
        - reference_id: PMID:25331875
          supporting_text: "Xylose phosphorylation functions as a molecular switch
            to regulate proteoglycan biosynthesis."
  - term:
      id: GO:0005515
      label: protein binding
    evidence_type: IPI
    original_reference_id: PMID:25789606
    review:
      summary: Vague term. Paper describes a secretory kinase complex (FAM20C) 
        that phosphorylates extracellular proteins including decorin. This is 
        enzyme-substrate interaction during biosynthesis.
      action: REMOVE
      reason: The term "protein binding" is uninformative per curation 
        guidelines. PMID:25789606 demonstrates that decorin is phosphorylated by
        the secretory kinase FAM20C. This enzyme-substrate interaction during 
        decorin biosynthesis/modification does not represent a molecular 
        function of decorin itself and should not be annotated as "protein 
        binding."
      supported_by:
        - reference_id: PMID:25789606
          supporting_text: "A secretory kinase complex regulates extracellular protein
            phosphorylation."
  - term:
      id: GO:0005576
      label: extracellular region
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-2022056
    review:
      summary: Reactome pathway annotation for DSPG/CSPG translocation to 
        lysosome for degradation. Decorin (as a dermatan sulfate proteoglycan) 
        is secreted to extracellular region and eventually degraded. Correct but
        redundant with other extracellular annotations.
      action: ACCEPT
      reason: Correct annotation from Reactome pathway curation. Decorin as a 
        dermatan/chondroitin sulfate proteoglycan is secreted to extracellular 
        region before eventual lysosomal degradation. While redundant with IBA 
        and IEA annotations to the same term, TAS evidence from curated pathways
        is valid.
      supported_by:
        - reference_id: Reactome:R-HSA-2022056
          supporting_text: "DSPG and CSPG translocate to the lysosome for degradation"
  - term:
      id: GO:0005576
      label: extracellular region
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-2022065
    review:
      summary: Reactome pathway annotation for DSPG secretion. Decorin as a 
        dermatan sulfate proteoglycan is secreted to extracellular region. 
        Correct but redundant with other extracellular annotations.
      action: ACCEPT
      reason: Correct annotation from Reactome pathway curation showing decorin 
        secretion to extracellular space. While redundant with other 
        annotations, TAS evidence from curated pathways adds value by connecting
        to specific biological process (DSPG secretion).
      supported_by:
        - reference_id: Reactome:R-HSA-2022065
          supporting_text: "Various forms of dermatan sulfate are excreted from the
            cell once formed"
  - term:
      id: GO:0005576
      label: extracellular region
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-2022911
    review:
      summary: Reactome pathway annotation for CSPG secretion. Decorin can carry
        chondroitin sulfate GAG chain and is secreted to extracellular region. 
        Correct but redundant with other extracellular annotations.
      action: ACCEPT
      reason: Correct annotation from Reactome pathway curation. Decorin can 
        exist as chondroitin sulfate proteoglycan (CSPG) or dermatan sulfate 
        proteoglycan (DSPG) depending on tissue. TAS evidence from curated 
        secretion pathway is valid though redundant.
      supported_by:
        - reference_id: Reactome:R-HSA-2022911
          supporting_text: "they are secreted out into the extracellular matrix (ECM)"
  - term:
      id: GO:0005796
      label: Golgi lumen
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-2022065
    review:
      summary: Reactome pathway annotation for DSPG biosynthesis/modification in
        Golgi during secretion. Decorin transiently passes through Golgi lumen 
        where GAG chain is modified (SO4 transfer to GalNAc by CHST14).
      action: KEEP_AS_NON_CORE
      reason: Correct annotation reflecting decorin's transit through the Golgi 
        lumen during biosynthesis and GAG chain modification. However, this is a
        transient biosynthetic localization, not decorin's mature functional 
        localization. The mature, functional protein resides in extracellular 
        matrix. Marking as non-core to distinguish from the primary functional 
        location.
      supported_by:
        - reference_id: Reactome:R-HSA-2022065
          supporting_text: "unknown but most likely involves the trans-golgi network"
  - term:
      id: GO:0005796
      label: Golgi lumen
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-2022911
    review:
      summary: Reactome pathway annotation for CSPG biosynthesis/secretion. 
        Decorin transiently passes through Golgi lumen during biosynthesis where
        GAG chain modifications occur.
      action: KEEP_AS_NON_CORE
      reason: Correct annotation reflecting transient Golgi localization during 
        proteoglycan biosynthesis. Decorin's chondroitin/dermatan sulfate GAG 
        chain is assembled and modified in Golgi. However, this is biosynthetic 
        transit, not the mature functional localization. Marking as non-core.
      supported_by:
        - reference_id: Reactome:R-HSA-2022911
          supporting_text: "they are secreted out into the extracellular matrix"
  - term:
      id: GO:0005796
      label: Golgi lumen
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-9940993
    review:
      summary: Reactome pathway for xylose dephosphorylation by PXYLP1 during 
        GAG chain biosynthesis. Decorin present in Golgi lumen during this 
        modification step.
      action: KEEP_AS_NON_CORE
      reason: Correct annotation from Reactome GAG biosynthesis pathway. PXYLP1 
        dephosphorylates the xylose moiety on the tetrasaccharide linker region 
        of decorin's GAG chain attachment site in Golgi. Transient biosynthetic 
        localization, not core functional location. Marking as non-core.
      supported_by:
        - reference_id: Reactome:R-HSA-9940993
          supporting_text: "PXYLP1 dephosphorylates Xyl moiety"
  - term:
      id: GO:0005796
      label: Golgi lumen
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-9941039
    review:
      summary: Reactome pathway for xylose phosphorylation by FAM20B during GAG 
        chain biosynthesis. Decorin present in Golgi lumen during this 
        modification step.
      action: KEEP_AS_NON_CORE
      reason: Correct annotation from Reactome GAG biosynthesis pathway. FAM20B 
        phosphorylates the xylose moiety on decorin's GAG attachment site linker
        in Golgi. This phosphorylation acts as a regulatory switch for 
        proteoglycan biosynthesis. Transient biosynthetic localization. Marking 
        as non-core.
      supported_by:
        - reference_id: Reactome:R-HSA-9941039
          supporting_text: "FAM20B phosphorylates Xyl moiety"
  - term:
      id: GO:0005796
      label: Golgi lumen
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-9941305
    review:
      summary: Reactome pathway for sulfate transfer by UST to 
        GlcA-GalNAc-6-sulfate during dermatan sulfate biosynthesis. Decorin 
        present in Golgi during GAG chain sulfation.
      action: KEEP_AS_NON_CORE
      reason: Correct annotation from Reactome dermatan sulfate biosynthesis 
        pathway. UST transfers sulfate to position 2 of GlcA in the decorin GAG 
        chain in Golgi lumen. Transient biosynthetic localization during GAG 
        chain modification. Marking as non-core.
      supported_by:
        - reference_id: Reactome:R-HSA-9941305
          supporting_text: "UST transfers sulfate to (2-)GlcA-GalNAc-6-sulfate"
  - term:
      id: GO:0005796
      label: Golgi lumen
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-9941312
    review:
      summary: Reactome pathway for sulfate transfer by CHST15 during GAG 
        biosynthesis. Decorin present in Golgi during chondroitin/dermatan 
        sulfate chain sulfation.
      action: KEEP_AS_NON_CORE
      reason: Correct annotation from Reactome GAG biosynthesis pathway. CHST15 
        transfers sulfate to GalNAc-4-sulfate residues in decorin's GAG chain in
        Golgi. Transient biosynthetic localization. Marking as non-core.
      supported_by:
        - reference_id: Reactome:R-HSA-9941312
          supporting_text: "CHST15 transfers sulfate to (6-)GalNAc-4-sulfate"
  - term:
      id: GO:0016239
      label: positive regulation of macroautophagy
    evidence_type: IDA
    original_reference_id: PMID:23798385
    review:
      summary: Decorin induces autophagy in endothelial cells via VEGFR2 
        signaling and Peg3 induction, leading to transcriptional activation of 
        Beclin 1 and LC3. This is experimentally demonstrated with direct assays
        showing autophagosome formation.
      action: KEEP_AS_NON_CORE
      reason: Well-supported experimental finding (IDA) from PMID:23798385. 
        Decorin binding to VEGFR2 on endothelial cells triggers Peg3-dependent 
        autophagy and angiogenesis suppression. However, this is a downstream 
        consequence of decorin's receptor binding activity in specific cell 
        types (endothelial cells) rather than a core function. Decorin's core 
        functions are collagen fibril organization and TGF-beta sequestration in
        the ECM. The autophagy induction represents a secondary signaling 
        effect. Marking as non-core.
      supported_by:
        - reference_id: PMID:23798385
          supporting_text: "Decorin evoked Peg3-dependent autophagy in both microvascular
            and macrovascular endothelial cells leading to suppression of angiogenesis."
  - term:
      id: GO:0016239
      label: positive regulation of macroautophagy
    evidence_type: IGI
    original_reference_id: PMID:23798385
    review:
      summary: Same biological process as IDA annotation above, but IGI evidence
        code indicates genetic interaction studies (likely Peg3 or VEGFR2 
        knockdown experiments) demonstrating decorin's role in autophagy.
      action: KEEP_AS_NON_CORE
      reason: Duplicate of the IDA annotation with different evidence code (IGI 
        - inferred from genetic interaction). Same rationale applies - decorin 
        induces autophagy via VEGFR2/Peg3 pathway in endothelial cells. This is 
        a secondary signaling activity rather than core ECM structural function.
        Marking as non-core. The IGI evidence likely comes from genetic 
        perturbation experiments (siRNA of Peg3 or VEGFR2) showing decorin 
        requires these factors for autophagy induction.
      supported_by:
        - reference_id: PMID:23798385
          supporting_text: "Peg3 coimmunoprecipitated with Beclin 1 and LC3 and was
            required for maintaining basal levels of Beclin 1."
  - term:
      id: GO:0005515
      label: protein binding
    evidence_type: IPI
    original_reference_id: PMID:11598131
    review:
      summary: Vague term. PMID:11598131 shows WISP-1 (CCN4, a matricellular 
        protein) binds to decorin and biglycan. While this is a real 
        interaction, "protein binding" is too uninformative per curation 
        guidelines.
      action: MARK_AS_OVER_ANNOTATED
      reason: The term "protein binding" is uninformative per curation 
        guidelines. While PMID:11598131 demonstrates a genuine interaction 
        between decorin and WISP-1, this is a peripheral binding partner 
        compared to decorin's core functions (collagen binding, TGF-beta 
        binding, growth factor receptor binding). Without a more specific GO 
        term for WISP-1 binding, this should be marked as over-annotated rather 
        than representing a core molecular function.
      supported_by:
        - reference_id: PMID:11598131
          supporting_text: "WISP-1 binds to decorin and biglycan."
  - term:
      id: GO:0030021
      label: extracellular matrix structural constituent conferring compression 
        resistance
    evidence_type: RCA
    original_reference_id: PMID:28327460
    review:
      summary: Incorrect molecular function for decorin. This term (GO:0030021) 
        is appropriate for large aggregating proteoglycans like aggrecan that 
        provide compression resistance in cartilage. Decorin's core function is 
        collagen fibril organization, not compression resistance.
      action: MODIFY
      reason: This RCA (inferred from reviewed computational analysis) 
        annotation is a mis-annotation. GO:0030021 describes the ability to 
        resist compression forces, which is the role of large cartilage 
        proteoglycans like aggrecan with multiple GAG chains. Decorin is a small
        proteoglycan (SLRP) with a single GAG chain whose primary function is 
        regulating collagen fibril assembly and diameter, not providing 
        compression resistance. Should be replaced with GO:0005518 (collagen 
        binding) which represents decorin's actual core molecular function.
      proposed_replacement_terms:
        - id: GO:0005518
          label: collagen binding
      supported_by:
        - reference_id: Reactome:R-HSA-2327909
          supporting_text: "DCN binding regulates fibrillogenesis (Vogel et al. 1984,
            Orgel et al. 2006)."
  - term:
      id: GO:0031012
      label: extracellular matrix
    evidence_type: HDA
    original_reference_id: PMID:28327460
    review:
      summary: Correct cellular component annotation from HDA (high-throughput 
        direct assay) proteomics. Decorin is a core extracellular matrix 
        proteoglycan.
      action: ACCEPT
      reason: Accurate annotation based on proteomics characterization of stem 
        cell-derived extracellular matrices. Decorin is a major structural 
        component of the ECM where it regulates collagen fibrillogenesis and 
        sequesters TGF-beta. This is a core localization for decorin's function.
      supported_by:
        - reference_id: PMID:28327460
          supporting_text: "Comprehensive proteomic characterization of stem cell-derived
            extracellular matrices."
  - term:
      id: GO:0030021
      label: extracellular matrix structural constituent conferring compression 
        resistance
    evidence_type: RCA
    original_reference_id: PMID:28675934
    review:
      summary: Incorrect molecular function for decorin. Same issue as other 
        GO:0030021 annotations - decorin regulates collagen fibrillogenesis, not
        compression resistance.
      action: MODIFY
      reason: Mis-annotation from RCA (reviewed computational analysis). Decorin
        is a small leucine-rich proteoglycan that regulates collagen fibril 
        organization, not a large aggregating proteoglycan that provides 
        compression resistance. This term is inappropriate for decorin's 
        molecular function.
      proposed_replacement_terms:
        - id: GO:0005518
          label: collagen binding
      supported_by:
        - reference_id: Reactome:R-HSA-2327909
          supporting_text: "DCN binding regulates fibrillogenesis (Vogel et al. 1984,
            Orgel et al. 2006)."
  - term:
      id: GO:0031012
      label: extracellular matrix
    evidence_type: HDA
    original_reference_id: PMID:28675934
    review:
      summary: Correct cellular component annotation from HDA proteomics of 
        normal and diseased tissues. Decorin is a core ECM component.
      action: ACCEPT
      reason: Accurate annotation based on proteomics characterization of ECM 
        from normal and diseased tissues. Decorin is a fundamental structural 
        proteoglycan of the extracellular matrix. This is a core localization.
      supported_by:
        - reference_id: PMID:28675934
          supporting_text: "Characterization of the Extracellular Matrix of Normal
            and Diseased Tissues Using Proteomics."
  - term:
      id: GO:0030021
      label: extracellular matrix structural constituent conferring compression 
        resistance
    evidence_type: ISS
    original_reference_id: GO_REF:0000024
    review:
      summary: Incorrect molecular function inferred from sequence similarity. 
        Decorin does not provide compression resistance - it regulates collagen 
        fibril organization.
      action: MODIFY
      reason: This ISS (inferred from sequence/structural similarity) annotation
        is incorrect. While decorin shares sequence similarity with other SLRPs,
        its molecular function is distinct from large aggregating proteoglycans.
        Decorin regulates collagen fibril assembly and spacing through direct 
        collagen binding, not compression resistance.
      proposed_replacement_terms:
        - id: GO:0005518
          label: collagen binding
      supported_by:
        - reference_id: GO_REF:0000024
          supporting_text: "Manual transfer of experimentally-verified manual GO annotation
            data to orthologs by curator judgment of sequence similarity."
  - term:
      id: GO:0030021
      label: extracellular matrix structural constituent conferring compression 
        resistance
    evidence_type: RCA
    original_reference_id: PMID:20551380
    review:
      summary: Incorrect molecular function. Decorin regulates collagen 
        organization, not compression resistance. Same issue as other GO:0030021
        annotations.
      action: MODIFY
      reason: Mis-annotation from RCA analysis. Decorin's core molecular 
        function is collagen binding and regulation of fibrillogenesis, not 
        providing compression resistance to ECM.
      proposed_replacement_terms:
        - id: GO:0005518
          label: collagen binding
      supported_by:
        - reference_id: Reactome:R-HSA-2327909
          supporting_text: "DCN binding regulates fibrillogenesis (Vogel et al. 1984,
            Orgel et al. 2006)."
  - term:
      id: GO:0030021
      label: extracellular matrix structural constituent conferring compression 
        resistance
    evidence_type: RCA
    original_reference_id: PMID:25037231
    review:
      summary: Incorrect molecular function. Decorin regulates collagen 
        organization, not compression resistance. Same issue as other GO:0030021
        annotations.
      action: MODIFY
      reason: Mis-annotation from RCA of ECM proteomics data. Decorin's 
        molecular function is collagen binding and fibril organization, not 
        compression resistance.
      proposed_replacement_terms:
        - id: GO:0005518
          label: collagen binding
      supported_by:
        - reference_id: Reactome:R-HSA-2327909
          supporting_text: "DCN binding regulates fibrillogenesis (Vogel et al. 1984,
            Orgel et al. 2006)."
  - term:
      id: GO:0030021
      label: extracellular matrix structural constituent conferring compression 
        resistance
    evidence_type: RCA
    original_reference_id: PMID:27559042
    review:
      summary: Incorrect molecular function. Decorin regulates collagen 
        organization, not compression resistance. Same issue as other GO:0030021
        annotations.
      action: MODIFY
      reason: Mis-annotation from RCA analysis. Decorin is a small proteoglycan 
        that regulates collagen fibril assembly, not a large aggregating 
        proteoglycan that provides compression resistance.
      proposed_replacement_terms:
        - id: GO:0005518
          label: collagen binding
      supported_by:
        - reference_id: Reactome:R-HSA-2327909
          supporting_text: "DCN binding regulates fibrillogenesis (Vogel et al. 1984,
            Orgel et al. 2006)."
  - term:
      id: GO:0031012
      label: extracellular matrix
    evidence_type: HDA
    original_reference_id: PMID:25037231
    review:
      summary: Correct cellular component annotation from HDA proteomics of 
        metastatic colon cancers. Decorin is an ECM component.
      action: ACCEPT
      reason: Accurate annotation from proteomic analysis of ECM in cancer 
        tissues. Decorin is a core extracellular matrix proteoglycan.
      supported_by:
        - reference_id: PMID:25037231
          supporting_text: "Extracellular matrix signatures of human primary metastatic
            colon cancers and their metastases to liver."
  - term:
      id: GO:0005576
      label: extracellular region
    evidence_type: HDA
    original_reference_id: PMID:27068509
    review:
      summary: Correct cellular component annotation from HDA proteomics of 
        human varicose veins. Decorin is in extracellular region/ECM.
      action: ACCEPT
      reason: Accurate annotation from proteomic analysis of ECM remodeling in 
        varicose veins. Decorin is secreted to extracellular region. Correct but
        less specific than extracellular matrix.
      supported_by:
        - reference_id: PMID:27068509
          supporting_text: "Extracellular matrix remodelling in response to venous
            hypertension: proteomics of human varicose veins."
  - term:
      id: GO:0031012
      label: extracellular matrix
    evidence_type: HDA
    original_reference_id: PMID:27559042
    review:
      summary: Correct cellular component annotation from HDA glycoproteomics. 
        Decorin is an ECM proteoglycan.
      action: ACCEPT
      reason: Accurate annotation from glycoproteomics analysis of human atrial 
        fibrillation tissues. Decorin is a core extracellular matrix 
        proteoglycan.
      supported_by:
        - reference_id: PMID:27559042
          supporting_text: "Glycoproteomics Reveals Decorin Peptides With Anti-Myostatin
            Activity in Human Atrial Fibrillation."
  - term:
      id: GO:0005615
      label: extracellular space
    evidence_type: HDA
    original_reference_id: PMID:20551380
    review:
      summary: Correct cellular component annotation from HDA proteomics of 
        human aorta extracellular space. Decorin is secreted to extracellular 
        space.
      action: ACCEPT
      reason: Accurate annotation from proteomic characterization of aorta 
        extracellular space components. Decorin functions in extracellular 
        space/ECM.
      supported_by:
        - reference_id: PMID:20551380
          supporting_text: "Proteomics characterization of extracellular space components
            in the human aorta."
  - term:
      id: GO:0031012
      label: extracellular matrix
    evidence_type: HDA
    original_reference_id: PMID:20551380
    review:
      summary: Correct cellular component annotation from HDA proteomics of 
        human aorta ECM. Decorin is a core ECM proteoglycan.
      action: ACCEPT
      reason: Accurate annotation from proteomic characterization of human aorta
        extracellular matrix. Decorin is a fundamental structural component of 
        the ECM.
      supported_by:
        - reference_id: PMID:20551380
          supporting_text: "Proteomics characterization of extracellular space components
            in the human aorta."
  - term:
      id: GO:0031012
      label: extracellular matrix
    evidence_type: ISS
    original_reference_id: PMID:22261194
    review:
      summary: Correct cellular component annotation from ISS (inferred from 
        sequence similarity) analysis of cardiac ECM. Decorin is an ECM 
        proteoglycan.
      action: ACCEPT
      reason: Accurate annotation based on sequence similarity inference 
        supported by proteomic analysis of cardiac ECM remodeling. Decorin is a 
        core extracellular matrix component.
      supported_by:
        - reference_id: PMID:22261194
          supporting_text: "Proteomics analysis of cardiac extracellular matrix remodeling
            in a porcine model of ischemia/reperfusion injury."
  - term:
      id: GO:0010596
      label: negative regulation of endothelial cell migration
    evidence_type: IDA
    original_reference_id: PMID:23798385
    review:
      summary: Decorin suppresses endothelial cell migration via 
        VEGFR2/Peg3/autophagy pathway. This is experimentally demonstrated 
        (IDA).
      action: KEEP_AS_NON_CORE
      reason: Well-supported experimental finding from PMID:23798385 showing 
        decorin's anti-angiogenic effects on endothelial cells. However, this is
        a downstream consequence of decorin's RTK binding activity rather than a
        core function. Decorin's core functions are collagen fibril organization
        and TGF-beta sequestration. The endothelial cell effects represent 
        peripheral signaling activities. Marking as non-core.
      supported_by:
        - reference_id: PMID:23798385
          supporting_text: "Decorin evoked Peg3-dependent autophagy in both microvascular
            and macrovascular endothelial cells leading to suppression of angiogenesis."
  - term:
      id: GO:0016525
      label: negative regulation of angiogenesis
    evidence_type: IDA
    original_reference_id: PMID:23978385
    review:
      summary: Decorin suppresses angiogenesis. Note - PMID:23978385 is about 
        paclitaxel neurotoxicity, likely incorrect PMID. The correct reference 
        should be PMID:23798385 which demonstrates decorin's anti-angiogenic 
        effects.
      action: KEEP_AS_NON_CORE
      reason: Anti-angiogenic activity is documented for decorin (should cite 
        PMID:23798385 not PMID:23978385). Decorin binding to VEGFR2 suppresses 
        angiogenesis via autophagy induction. However, this is a secondary 
        signaling function rather than core ECM structural function. Decorin's 
        core functions are collagen organization and TGF-beta sequestration. 
        Marking as non-core.
      additional_reference_ids:
        - PMID:23798385
      supported_by:
        - reference_id: PMID:23798385
          supporting_text: "Decorin evoked Peg3-dependent autophagy in both microvascular
            and macrovascular endothelial cells leading to suppression of angiogenesis."
  - term:
      id: GO:0045944
      label: positive regulation of transcription by RNA polymerase II
    evidence_type: IGI
    original_reference_id: PMID:23798385
    review:
      summary: Decorin induces transcription of BECN1 and MAPLC3A genes via 
        Peg3. This is demonstrated by genetic interaction studies (IGI).
      action: KEEP_AS_NON_CORE
      reason: Experimental finding from PMID:23798385 showing decorin (via Peg3)
        induces transcription of autophagy genes. This is a downstream signaling
        consequence in endothelial cells, not a core function. Decorin's core 
        functions are ECM structural roles (collagen organization, TGF-beta 
        sequestration). This transcriptional regulatory activity is a peripheral
        cell signaling effect. Marking as non-core.
      supported_by:
        - reference_id: PMID:23798385
          supporting_text: "Decorin, via Peg3, induced transcription of Beclin 1 and
            microtubule-associated protein 1 light chain 3 alpha genes, thereby leading
            to a protracted autophagic program."
  - term:
      id: GO:0051897
      label: positive regulation of phosphatidylinositol 3-kinase/protein kinase
        B signal transduction
    evidence_type: IDA
    original_reference_id: PMID:23798385
    review:
      summary: Decorin activates PI3K/AKT signaling in endothelial cells. 
        Demonstrated experimentally (IDA) in context of autophagy induction.
      action: KEEP_AS_NON_CORE
      reason: Experimental finding from PMID:23798385 in endothelial cell 
        signaling context. This is a downstream signaling effect, not a core 
        function. Decorin's core functions are ECM structural (collagen 
        organization, TGF-beta sequestration). PI3K/AKT activation is a 
        peripheral cell signaling activity. Marking as non-core.
      supported_by:
        - reference_id: PMID:23798385
          supporting_text: "decorin, by binding to VEGFR2, triggers a signaling cascade
            leading to induction of Class III PI3K"
  - term:
      id: GO:0051901
      label: positive regulation of mitochondrial depolarization
    evidence_type: IGI
    original_reference_id: PMID:23798385
    review:
      summary: Decorin induces loss of mitochondrial membrane potential in 
        endothelial cells via VEGFR2/Peg3 pathway. Genetic interaction evidence 
        (IGI).
      action: KEEP_AS_NON_CORE
      reason: Experimental finding from PMID:23798385 showing decorin causes 
        mitochondrial depolarization in endothelial cells as part of 
        autophagy/anti-angiogenic effects. This is a downstream cellular effect,
        not a core function. Decorin's core functions are ECM structural. 
        Marking as non-core.
      supported_by:
        - reference_id: PMID:23798385
          supporting_text: "decorin induced VEGFR2-dependent mitochondrial fragmentation
            and loss of mitochondrial membrane potential"
  - term:
      id: GO:0090141
      label: positive regulation of mitochondrial fission
    evidence_type: IGI
    original_reference_id: PMID:23798385
    review:
      summary: Decorin induces mitochondrial fragmentation/fission in 
        endothelial cells. Genetic interaction evidence (IGI).
      action: KEEP_AS_NON_CORE
      reason: Experimental finding from PMID:23798385 showing decorin causes 
        mitochondrial fission in endothelial cells as part of its 
        anti-angiogenic effects. This is a downstream cellular consequence, not 
        a core function. Decorin's core functions are ECM structural. Marking as
        non-core.
      supported_by:
        - reference_id: PMID:23798385
          supporting_text: "decorin induced VEGFR2-dependent mitochondrial fragmentation
            and loss of mitochondrial membrane potential"
  - term:
      id: GO:1900747
      label: negative regulation of vascular endothelial growth factor signaling
        pathway
    evidence_type: IDA
    original_reference_id: PMID:23798385
    review:
      summary: Decorin antagonizes VEGF signaling by binding VEGFR2 and 
        competing with VEGFA. Experimentally demonstrated (IDA).
      action: KEEP_AS_NON_CORE
      reason: Well-supported experimental finding from PMID:23798385. Decorin 
        binds VEGFR2 in region overlapping with VEGFA binding site, antagonizing
        VEGF signaling. However, this is a cell signaling activity rather than 
        decorin's core ECM structural functions (collagen organization, TGF-beta
        sequestration). Marking as non-core.
      supported_by:
        - reference_id: PMID:23798385
          supporting_text: "decorin interacted with VEGF receptor 2 (VEGFR2) in a
            region overlapping with its natural ligand VEGFA"
  - term:
      id: GO:0010508
      label: positive regulation of autophagy
    evidence_type: IDA
    original_reference_id: PMID:23798385
    review:
      summary: Decorin induces autophagy in endothelial cells. Parent term of 
        GO:0016239 (positive regulation of macroautophagy). Experimentally 
        demonstrated (IDA).
      action: KEEP_AS_NON_CORE
      reason: Experimental finding from PMID:23798385 - same biological process 
        as the more specific term GO:0016239 (positive regulation of 
        macroautophagy) already annotated. Decorin induces autophagy via 
        VEGFR2/Peg3 pathway. This is a secondary signaling function, not core 
        ECM structural function. Marking as non-core.
      supported_by:
        - reference_id: PMID:23798385
          supporting_text: "Decorin evoked Peg3-dependent autophagy in both microvascular
            and macrovascular endothelial cells leading to suppression of angiogenesis."
  - term:
      id: GO:0005796
      label: Golgi lumen
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-2022052
    review:
      summary: Reactome pathway for conversion of GlcA to IdoA (DSE enzyme) 
        during dermatan sulfate biosynthesis. Decorin transiently in Golgi 
        during GAG modification.
      action: KEEP_AS_NON_CORE
      reason: Correct annotation from Reactome dermatan sulfate biosynthesis 
        pathway. DSE converts GlcA to IdoA in decorin's GAG chain in Golgi. 
        Transient biosynthetic localization, not core functional location. 
        Marking as non-core.
      supported_by:
        - reference_id: Reactome:R-HSA-2022052
          supporting_text: "DSE converts GlcA to IdoA"
  - term:
      id: GO:0005796
      label: Golgi lumen
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-2022063
    review:
      summary: Reactome pathway for sulfate transfer by CHST14 to GalNAc in 
        dermatan sulfate. Decorin transiently in Golgi during GAG biosynthesis.
      action: KEEP_AS_NON_CORE
      reason: Correct annotation from Reactome dermatan sulfate biosynthesis 
        pathway. CHST14 transfers sulfate to GalNAc residues in decorin's GAG 
        chain in Golgi. Transient biosynthetic localization. Marking as 
        non-core.
      supported_by:
        - reference_id: Reactome:R-HSA-2022063
          supporting_text: "CHST14 transfers SO4(2-) to GalNAc in dermatan or DS"
  - term:
      id: GO:0005796
      label: Golgi lumen
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-3636919
    review:
      summary: Reactome pathway for defective CHST14 (EDS musculocontractural 
        type mutation). Decorin present in Golgi during GAG biosynthesis.
      action: KEEP_AS_NON_CORE
      reason: Correct annotation from Reactome disease pathway showing decorin's
        presence in Golgi during GAG chain modification. Transient biosynthetic 
        localization. Marking as non-core.
      supported_by:
        - reference_id: Reactome:R-HSA-3636919
          supporting_text: "Defective CHST14 does not transfer SO4(2-) to GalNAc in
            dermatan or DS"
  - term:
      id: GO:0003723
      label: RNA binding
    evidence_type: HDA
    original_reference_id: PMID:22658674
    review:
      summary: Decorin detected in mRNA-binding protein atlas from HDA 
        (high-throughput) study. However, RNA binding is not a characterized 
        molecular function of decorin.
      action: REMOVE
      reason: This annotation from PMID:22658674 (mammalian mRNA-binding protein
        atlas) is likely a false positive from high-throughput screen. Decorin 
        is a secreted extracellular proteoglycan with well-characterized 
        molecular functions (collagen binding, TGF-beta binding, growth factor 
        receptor binding). RNA binding has never been reported as a decorin 
        function in focused studies and makes no biological sense for a secreted
        ECM protein. Should be removed as over-annotation from HDA screen 
        artifact.
      supported_by:
        - reference_id: PMID:22658674
          supporting_text: "Insights into RNA biology from an atlas of mammalian mRNA-binding
            proteins."
  - term:
      id: GO:0005576
      label: extracellular region
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-2534248
    review:
      summary: Reactome pathway for decorin degradation by MMPs (MMP2, MMP3, 
        MMP7) in extracellular region.
      action: ACCEPT
      reason: Correct annotation from Reactome ECM degradation pathway. Decorin 
        is degraded by matrix metalloproteinases in the extracellular region 
        where it functions. This confirms decorin's localization to 
        extracellular space.
      supported_by:
        - reference_id: Reactome:R-HSA-2534248
          supporting_text: "DCN (decorin) degradation by MMP2, MMP3, MMP7"
  - term:
      id: GO:0005576
      label: extracellular region
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-3828025
    review:
      summary: Reactome pathway for decorin degradation by MMP14 in 
        extracellular region.
      action: ACCEPT
      reason: Correct annotation from Reactome ECM degradation pathway. Decorin 
        is degraded by MMP14 (membrane-type MMP) in the extracellular region. 
        This confirms decorin's extracellular localization.
      supported_by:
        - reference_id: Reactome:R-HSA-3828025
          supporting_text: "DCN (decorin) degradation by MMP14"
  - term:
      id: GO:0005576
      label: extracellular region
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-2327909
    review:
      summary: Reactome pathway for decorin binding to collagen I, II, III, VI 
        fibrils in extracellular region.
      action: ACCEPT
      reason: Correct annotation from Reactome collagen binding pathway. This is
        a core function of decorin - binding to collagen fibrils in the 
        extracellular matrix to regulate fibrillogenesis. Decorin functions in 
        extracellular region/ECM.
      supported_by:
        - reference_id: Reactome:R-HSA-2327909
          supporting_text: "DCN binds collagen I, II, III, VI fibrils"
  - term:
      id: GO:0005576
      label: extracellular region
    evidence_type: TAS
    original_reference_id: Reactome:R-NUL-2466133
    review:
      summary: Reactome pathway for SLRPs binding TGF-beta in extracellular 
        region. Decorin sequesters TGF-beta in ECM.
      action: ACCEPT
      reason: Correct annotation from Reactome TGF-beta signaling pathway. 
        Decorin binding and sequestering TGF-beta in the extracellular region is
        one of its core functions. This annotation represents a fundamental 
        aspect of decorin biology.
      supported_by:
        - reference_id: Reactome:R-NUL-2466133
          supporting_text: "DCN binding is thought to sequester TGF-Beta extracellularly,
            thereby diminishing its biological activity"
  - term:
      id: GO:0005796
      label: Golgi lumen
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1878002
    review:
      summary: Reactome pathway for xylose transfer to decorin core protein by 
        XYLTs (tetrasaccharide linker biosynthesis). Decorin in Golgi during GAG
        chain initiation.
      action: KEEP_AS_NON_CORE
      reason: Correct annotation from Reactome GAG biosynthesis pathway. XYLTs 
        transfer xylose to Ser-34 of decorin to initiate tetrasaccharide linker 
        formation in Golgi. Transient biosynthetic localization. Marking as 
        non-core.
      supported_by:
        - reference_id: Reactome:R-HSA-1878002
          supporting_text: "XYLTs transfer Xyl to core protein"
  - term:
      id: GO:0005796
      label: Golgi lumen
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1889955
    review:
      summary: Reactome pathway for GlcA transfer to tetrasaccharide linker by 
        B3GAT dimers. Decorin in Golgi during GAG linker biosynthesis.
      action: KEEP_AS_NON_CORE
      reason: Correct annotation from Reactome tetrasaccharide linker 
        biosynthesis pathway. B3GAT transfers GlcA to the linker region of 
        decorin's GAG attachment site in Golgi. Transient biosynthetic 
        localization. Marking as non-core.
      supported_by:
        - reference_id: Reactome:R-HSA-1889955
          supporting_text: "B3GAT dimers transfer GlcA to tetrasaccharide linker"
  - term:
      id: GO:0005796
      label: Golgi lumen
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1889978
    review:
      summary: Reactome pathway for Gal transfer to tetrasaccharide linker by 
        B3GALT6. Decorin in Golgi during GAG linker assembly.
      action: KEEP_AS_NON_CORE
      reason: Correct annotation from Reactome tetrasaccharide linker 
        biosynthesis pathway. B3GALT6 transfers galactose to the linker region 
        in Golgi. Transient biosynthetic localization. Marking as non-core.
      supported_by:
        - reference_id: Reactome:R-HSA-1889978
          supporting_text: "B3GALT6 transfers Gal to the tetrasaccharide linker"
  - term:
      id: GO:0005796
      label: Golgi lumen
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1889981
    review:
      summary: Reactome pathway for Gal transfer to xylosyl-unit by B4GALT7 
        (first step of tetrasaccharide linker). Decorin in Golgi during GAG 
        biosynthesis.
      action: KEEP_AS_NON_CORE
      reason: Correct annotation from Reactome tetrasaccharide linker 
        biosynthesis pathway. B4GALT7 transfers galactose to xylose on decorin 
        in Golgi. Transient biosynthetic localization. Marking as non-core.
      supported_by:
        - reference_id: Reactome:R-HSA-1889981
          supporting_text: "B4GALT7 transfers Gal group to xylosyl-unit of the tetrasaccharide
            linker"
  - term:
      id: GO:0005796
      label: Golgi lumen
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1971482
    review:
      summary: Reactome pathway for GalNAc transfer to CS linker glycan by 
        CSGALNACTs. Decorin in Golgi during chondroitin sulfate biosynthesis.
      action: KEEP_AS_NON_CORE
      reason: Correct annotation from Reactome chondroitin sulfate biosynthesis 
        pathway. CSGALNACTs transfer GalNAc to initiate CS chain on decorin in 
        Golgi. Transient biosynthetic localization. Marking as non-core.
      supported_by:
        - reference_id: Reactome:R-HSA-1971482
          supporting_text: "CSGALNACTs transfer GalNAc to CS linker glycan"
  - term:
      id: GO:0005796
      label: Golgi lumen
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-3560802
    review:
      summary: Reactome disease pathway for defective B3GAT3 (JDSSDHD mutation).
        Decorin present in Golgi during attempted GAG biosynthesis even with 
        defective enzyme.
      action: KEEP_AS_NON_CORE
      reason: Correct annotation from Reactome disease pathway. In JDSSDHD 
        (joint dislocations, short stature, craniofacial dysmorphism with or 
        without congenital heart defects), defective B3GAT3 cannot transfer 
        GlcA, but decorin substrates are still present in Golgi. Transient 
        biosynthetic localization. Marking as non-core.
      supported_by:
        - reference_id: Reactome:R-HSA-3560802
          supporting_text: "Defective B3GAT3 does not transfer GlcA to tetrasaccharide
            linker"
  - term:
      id: GO:0005796
      label: Golgi lumen
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-3560804
    review:
      summary: Reactome disease pathway for defective B4GALT7 (EDS progeroid 
        type mutation). Decorin present in Golgi even with defective GAG 
        biosynthesis enzyme.
      action: KEEP_AS_NON_CORE
      reason: Correct annotation from Reactome disease pathway. In EDS progeroid
        type, defective B4GALT7 cannot transfer Gal to xylose, but decorin is 
        still present in Golgi. Transient biosynthetic localization. Marking as 
        non-core.
      supported_by:
        - reference_id: Reactome:R-HSA-3560804
          supporting_text: "Defective B4GALT7 does not transfer Gal to xylosyl-unit
            of the tetrasaccharide linker"
  - term:
      id: GO:0005796
      label: Golgi lumen
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-4420365
    review:
      summary: Reactome disease pathway for defective B3GALT6 (EDSP2/SEMDJL1 
        mutations). Decorin present in Golgi even with defective GAG 
        biosynthesis.
      action: KEEP_AS_NON_CORE
      reason: Correct annotation from Reactome disease pathway. In EDSP2 and 
        SEMDJL1, defective B3GALT6 cannot transfer Gal to linker, but decorin is
        present in Golgi. Transient biosynthetic localization. Marking as 
        non-core.
      supported_by:
        - reference_id: Reactome:R-HSA-4420365
          supporting_text: "Defective B3GALT6 does not transfer Gal to the tetrasaccharide
            linker"
  - term:
      id: GO:0043202
      label: lysosomal lumen
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1793176
    review:
      summary: Reactome pathway for dermatan sulfate cleavage from proteoglycan 
        in lysosome during degradation. Decorin eventually degraded in 
        lysosomes.
      action: KEEP_AS_NON_CORE
      reason: Correct annotation from Reactome degradation pathway. Decorin (as 
        dermatan sulfate proteoglycan) is eventually internalized and degraded 
        in lysosomes, where DS GAG chains are cleaved. This represents the 
        terminal degradation step, not functional localization. Marking as 
        non-core.
      supported_by:
        - reference_id: Reactome:R-HSA-1793176
          supporting_text: "DS is cleaved from its proteoglycan"
  - term:
      id: GO:0043202
      label: lysosomal lumen
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-2065233
    review:
      summary: Reactome pathway for chondroitin sulfate cleavage from 
        proteoglycan in lysosome during degradation. Decorin eventually degraded
        in lysosomes.
      action: KEEP_AS_NON_CORE
      reason: Correct annotation from Reactome degradation pathway. Decorin (as 
        chondroitin sulfate proteoglycan) is eventually degraded in lysosomes 
        where CS chains are cleaved. Terminal degradation step, not functional 
        localization. Marking as non-core.
      supported_by:
        - reference_id: Reactome:R-HSA-2065233
          supporting_text: "CS is cleaved from its proteoglycan"
  - term:
      id: GO:0005796
      label: Golgi lumen
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1971483
    review:
      summary: Reactome pathway for sulfate transfer to GalNAc by CHST enzymes 
        during CS/DS biosynthesis. Decorin in Golgi during GAG sulfation.
      action: KEEP_AS_NON_CORE
      reason: Correct annotation from Reactome chondroitin/dermatan sulfate 
        biosynthesis pathway. CHST11/12/13/9 transfer sulfate to 4-position of 
        GalNAc in decorin's GAG chain in Golgi. Transient biosynthetic 
        localization. Marking as non-core.
      supported_by:
        - reference_id: Reactome:R-HSA-1971483
          supporting_text: "CHST11,12,13,9 transfer sulfate to (4-)GalNAc"
  - term:
      id: GO:0005796
      label: Golgi lumen
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1971487
    review:
      summary: Reactome pathway for GalNAc transfer to CS chain by chondroitin 
        polymerase complex. Decorin in Golgi during CS chain elongation.
      action: KEEP_AS_NON_CORE
      reason: Correct annotation from Reactome chondroitin sulfate biosynthesis 
        pathway. Chondroitin polymerase complex elongates CS chain on decorin by
        adding GalNAc residues in Golgi. Transient biosynthetic localization. 
        Marking as non-core.
      supported_by:
        - reference_id: Reactome:R-HSA-1971487
          supporting_text: "Chondroitin polymerase complex transfers GalNAc to CS
            chain"
  - term:
      id: GO:0005796
      label: Golgi lumen
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1971491
    review:
      summary: Reactome pathway for GlcA transfer to CS chain by chondroitin 
        polymerase complex. Decorin in Golgi during CS chain elongation.
      action: KEEP_AS_NON_CORE
      reason: Correct annotation from Reactome chondroitin sulfate biosynthesis 
        pathway. Chondroitin polymerase complex adds GlcA to decorin's CS chain 
        in Golgi. Transient biosynthetic localization. Marking as non-core.
      supported_by:
        - reference_id: Reactome:R-HSA-1971491
          supporting_text: "Chondroitin polymerase complex transfers GlcA to CS chain"
  - term:
      id: GO:0005796
      label: Golgi lumen
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-2018659
    review:
      summary: Reactome pathway for sulfate transfer by CHST15 to 
        GalNAc-4-sulfate (creating 4,6-disulfated GalNAc). Decorin in Golgi 
        during DS biosynthesis.
      action: KEEP_AS_NON_CORE
      reason: Correct annotation from Reactome dermatan sulfate biosynthesis 
        pathway. CHST15 adds additional sulfate to create disulfated GalNAc in 
        decorin's GAG chain in Golgi. Transient biosynthetic localization. 
        Marking as non-core.
      supported_by:
        - reference_id: Reactome:R-HSA-2018659
          supporting_text: "CHST15 transfers sulfate to (6-)GalNAc-4-sulfate"
  - term:
      id: GO:0005796
      label: Golgi lumen
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-2018682
    review:
      summary: Reactome pathway for sulfate transfer to position 6 of GalNAc by 
        CHST3/7. Decorin in Golgi during CS biosynthesis.
      action: KEEP_AS_NON_CORE
      reason: Correct annotation from Reactome chondroitin sulfate biosynthesis 
        pathway. CHST3/7 transfer sulfate to 6-position of GalNAc in decorin's 
        GAG chain in Golgi. Transient biosynthetic localization. Marking as 
        non-core.
      supported_by:
        - reference_id: Reactome:R-HSA-2018682
          supporting_text: "CHST3,7 transfer SO4(2-) to position 6 of GalNAc on chondroitin
            chains"
  - term:
      id: GO:0005796
      label: Golgi lumen
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-2022061
    review:
      summary: Reactome pathway for sulfation of iduronate (position 2) in 
        dermatan sulfate. Decorin in Golgi during DS modification.
      action: KEEP_AS_NON_CORE
      reason: Correct annotation from Reactome dermatan sulfate biosynthesis 
        pathway. Additional sulfation of position 2 of iduronate in decorin's DS
        chain occurs in Golgi. Transient biosynthetic localization. Marking as 
        non-core.
      supported_by:
        - reference_id: Reactome:R-HSA-2022061
          supporting_text: "Dermatan sulfate can be further sulfated on position 2
            of iduronate"
  - term:
      id: GO:0005796
      label: Golgi lumen
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-3595175
    review:
      summary: Reactome disease pathway for defective CHST3 (SEDCJD mutation - 
        spondyloepiphyseal dysplasia with congenital joint dislocations). 
        Decorin present in Golgi.
      action: KEEP_AS_NON_CORE
      reason: Correct annotation from Reactome disease pathway. In SEDCJD, 
        defective CHST3 cannot transfer sulfate to chondroitin, but decorin 
        substrates are present in Golgi. Transient biosynthetic localization. 
        Marking as non-core.
      supported_by:
        - reference_id: Reactome:R-HSA-3595175
          supporting_text: "Defective CHST3 does not transfer SO4(2-) to chondroitin"
  - term:
      id: GO:0005796
      label: Golgi lumen
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-3595176
    review:
      summary: Reactome disease pathway for defective CHSY1 (TPBS mutation - 
        Temtamy preaxial brachydactyly syndrome). Decorin present in Golgi.
      action: KEEP_AS_NON_CORE
      reason: Correct annotation from Reactome disease pathway. In TPBS, 
        defective CHSY1 cannot transfer GalNAc to chondroitin, but decorin is 
        present in Golgi. Transient biosynthetic localization. Marking as 
        non-core.
      supported_by:
        - reference_id: Reactome:R-HSA-3595176
          supporting_text: "Defective CHSY1 does not transfer GalNAc to chondroitin"
  - term:
      id: GO:0005796
      label: Golgi lumen
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-3595178
    review:
      summary: Reactome disease pathway for defective CHSY1 (TPBS mutation). 
        Decorin present in Golgi during defective CS biosynthesis.
      action: KEEP_AS_NON_CORE
      reason: Correct annotation from Reactome disease pathway. In TPBS, 
        defective CHSY1 cannot transfer GlcA to chondroitin, but decorin is 
        present in Golgi. Transient biosynthetic localization. Marking as 
        non-core.
      supported_by:
        - reference_id: Reactome:R-HSA-3595178
          supporting_text: "Defective CHSY1 does not transfer GlcA to chondroitin"
  - term:
      id: GO:0005796
      label: Golgi lumen
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-9632033
    review:
      summary: Reactome pathway for GalNAc transfer to CS chain by CSGALNACTs. 
        Decorin in Golgi during CS chain elongation.
      action: KEEP_AS_NON_CORE
      reason: Correct annotation from Reactome chondroitin sulfate biosynthesis 
        pathway. CSGALNACTs add GalNAc residues to elongate CS chain on decorin 
        in Golgi. Transient biosynthetic localization. Marking as non-core.
      supported_by:
        - reference_id: Reactome:R-HSA-9632033
          supporting_text: "CSGALNACTs transfer GalNAc to CS chain"
  - term:
      id: GO:0043202
      label: lysosomal lumen
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-2022056
    review:
      summary: Reactome pathway for DSPG/CSPG translocation to lysosome for 
        degradation. Decorin eventually degraded in lysosomal lumen.
      action: KEEP_AS_NON_CORE
      reason: Correct annotation from Reactome degradation pathway. Decorin (as 
        dermatan/chondroitin sulfate proteoglycan) is internalized and 
        translocated to lysosomes for degradation. Terminal degradation step, 
        not functional localization. Marking as non-core.
      supported_by:
        - reference_id: Reactome:R-HSA-2022056
          supporting_text: "DSPG and CSPG translocate to the lysosome for degradation"
  - term:
      id: GO:0009887
      label: animal organ morphogenesis
    evidence_type: TAS
    original_reference_id: PMID:7961765
    review:
      summary: Decorin expression during organogenesis and tissue 
        differentiation in mouse. TAS (traceable author statement) from 
        developmental study.
      action: KEEP_AS_NON_CORE
      reason: Correct annotation from PMID:7961765 studying murine decorin 
        expression during development. Decorin is expressed during organ 
        morphogenesis and tissue differentiation. However, this is a 
        developmental/tissue-specific process rather than decorin's core 
        molecular/cellular function. Decorin's core functions are collagen 
        fibril organization and TGF-beta sequestration. Marking as non-core.
      supported_by:
        - reference_id: PMID:7961765
          supporting_text: "The murine decorin. Complete cDNA cloning, genomic organization,
            chromosomal assignment, and expression during organogenesis and tissue
            differentiation."
references:
  - id: GO_REF:0000024
    title: Manual transfer of experimentally-verified manual GO annotation data 
      to orthologs by curator judgment of sequence similarity.
    findings: []
  - id: GO_REF:0000033
    title: Annotation inferences using phylogenetic trees
    findings: []
  - id: GO_REF:0000044
    title: Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular 
      Location vocabulary mapping, accompanied by conservative changes to GO 
      terms applied by UniProt.
    findings: []
  - id: GO_REF:0000107
    title: Automatic transfer of experimentally verified manual GO annotation 
      data to orthologs using Ensembl Compara.
    findings: []
  - id: PMID:11598131
    title: WISP-1 binds to decorin and biglycan.
    findings: []
  - id: PMID:1747115
    title: Interaction of the small proteoglycan decorin with fibronectin. 
      Involvement of the sequence NKISK of the core protein.
    findings: []
  - id: PMID:20026052
    title: Decorin is processed by three isoforms of bone morphogenetic 
      protein-1 (BMP1).
    findings: []
  - id: PMID:20551380
    title: Proteomics characterization of extracellular space components in the 
      human aorta.
    findings: []
  - id: PMID:22261194
    title: Proteomics analysis of cardiac extracellular matrix remodeling in a 
      porcine model of ischemia/reperfusion injury.
    findings: []
  - id: PMID:22658674
    title: Insights into RNA biology from an atlas of mammalian mRNA-binding 
      proteins.
    findings: []
  - id: PMID:23798385
    title: Decorin causes autophagy in endothelial cells via Peg3.
    findings: []
  - id: PMID:23978385
    title: 'The paradox of paclitaxel neurotoxicity: Mechanisms and unanswered questions.'
    findings: []
  - id: PMID:25037231
    title: Extracellular matrix signatures of human primary metastatic colon 
      cancers and their metastases to liver.
    findings: []
  - id: PMID:25331875
    title: Xylose phosphorylation functions as a molecular switch to regulate 
      proteoglycan biosynthesis.
    findings: []
  - id: PMID:25789606
    title: A secretory kinase complex regulates extracellular protein 
      phosphorylation.
    findings: []
  - id: PMID:27068509
    title: 'Extracellular matrix remodelling in response to venous hypertension: proteomics
      of human varicose veins.'
    findings: []
  - id: PMID:27559042
    title: Glycoproteomics Reveals Decorin Peptides With Anti-Myostatin Activity
      in Human Atrial Fibrillation.
    findings: []
  - id: PMID:28327460
    title: Comprehensive proteomic characterization of stem cell-derived 
      extracellular matrices.
    findings: []
  - id: PMID:28675934
    title: Characterization of the Extracellular Matrix of Normal and Diseased 
      Tissues Using Proteomics.
    findings: []
  - id: PMID:7961765
    title: The murine decorin. Complete cDNA cloning, genomic organization, 
      chromosomal assignment, and expression during organogenesis and tissue 
      differentiation.
    findings: []
  - id: Reactome:R-HSA-1793176
    title: DS is cleaved from its proteoglycan
    findings: []
  - id: Reactome:R-HSA-1878002
    title: XYLTs transfer Xyl to core protein
    findings: []
  - id: Reactome:R-HSA-1889955
    title: B3GAT dimers transfer GlcA to tetrasaccharide linker
    findings: []
  - id: Reactome:R-HSA-1889978
    title: B3GALT6 transfers Gal to the tetrasaccharide linker
    findings: []
  - id: Reactome:R-HSA-1889981
    title: B4GALT7 transfers Gal group to xylosyl-unit of the tetrasaccharide 
      linker
    findings: []
  - id: Reactome:R-HSA-1971482
    title: CSGALNACTs transfer GalNAc to CS linker glycan
    findings: []
  - id: Reactome:R-HSA-1971483
    title: CHST11,12,13,9 transfer sulfate to (4-)GalNAc
    findings: []
  - id: Reactome:R-HSA-1971487
    title: Chondroitin polymerase complex transfers GalNAc to CS chain
    findings: []
  - id: Reactome:R-HSA-1971491
    title: Chondroitin polymerase complex transfers GlcA to CS chain
    findings: []
  - id: Reactome:R-HSA-2018659
    title: CHST15 transfers sulfate to (6-)GalNAc-4-sulfate
    findings: []
  - id: Reactome:R-HSA-2018682
    title: CHST3,7 transfer SO4(2-) to position 6 of GalNAc on chondroitin 
      chains
    findings: []
  - id: Reactome:R-HSA-2022052
    title: DSE converts GlcA to IdoA
    findings: []
  - id: Reactome:R-HSA-2022056
    title: DSPG and CSPG translocate to the lysosome for degradation
    findings: []
  - id: Reactome:R-HSA-2022061
    title: Dermatan sulfate can be further sulfated on position 2 of iduronate
    findings: []
  - id: Reactome:R-HSA-2022063
    title: CHST14 transfers SO4(2-) to GalNAc in dermatan or DS
    findings: []
  - id: Reactome:R-HSA-2022065
    title: DSPGs are secreted
    findings: []
  - id: Reactome:R-HSA-2022911
    title: CSPG is secreted
    findings: []
  - id: Reactome:R-HSA-2065233
    title: CS is cleaved from its proteoglycan
    findings: []
  - id: Reactome:R-HSA-2327909
    title: DCN binds collagen I, II, III, VI fibrils
    findings: []
  - id: Reactome:R-HSA-2534248
    title: DCN (decorin) degradation by MMP2, MMP3, MMP7
    findings: []
  - id: Reactome:R-HSA-3560802
    title: Defective B3GAT3 does not transfer GlcA to tetrasaccharide linker
    findings: []
  - id: Reactome:R-HSA-3560804
    title: Defective B4GALT7 does not transfer Gal to xylosyl-unit of the 
      tetrasaccharide linker
    findings: []
  - id: Reactome:R-HSA-3595175
    title: Defective CHST3 does not transfer SO4(2-) to chondroitin
    findings: []
  - id: Reactome:R-HSA-3595176
    title: Defective CHSY1 does not transfer GalNAc to chondroitin
    findings: []
  - id: Reactome:R-HSA-3595178
    title: Defective CHSY1 does not transfer GlcA to chondroitin
    findings: []
  - id: Reactome:R-HSA-3636919
    title: Defective CHST14 does not transfer SO4(2-) to GalNAc in dermatan or 
      DS
    findings: []
  - id: Reactome:R-HSA-3828025
    title: DCN (decorin) degradation by MMP14
    findings: []
  - id: Reactome:R-HSA-4420365
    title: Defective B3GALT6 does not transfer Gal to the tetrasaccharide linker
    findings: []
  - id: Reactome:R-HSA-9632033
    title: CSGALNACTs transfer GalNAc to CS chain
    findings: []
  - id: Reactome:R-HSA-9940993
    title: PXYLP1 dephosphorylates Xyl moiety
    findings: []
  - id: Reactome:R-HSA-9941039
    title: FAM20B phosphorylates Xyl moiety
    findings: []
  - id: Reactome:R-HSA-9941305
    title: UST transfers sulfate to (2-)GlcA-GalNAc-6-sulfate
    findings: []
  - id: Reactome:R-HSA-9941312
    title: CHST15 transfers sulfate to (6-)GalNAc-4-sulfate
    findings: []
  - id: Reactome:R-NUL-2466133
    title: SLRPs bind TGF beta
    findings: []
  - id: file:human/DCN/DCN-deep-research-falcon.md
    title: Deep research report on DCN
    findings: []

DCN

Gene Description

Existing Annotations Review

References

📚 Additional Documentation

Deep Research Falcon

Question

Gene Research for Functional Annotation

⚠️ CRITICAL: Gene/Protein Identification Context

Target Gene/Protein Identity (from UniProt):

MANDATORY VERIFICATION STEPS:

If Gene Symbol is Ambiguous or You Cannot Find Relevant Literature:

Research Target:

Output

Gene Research for Functional Annotation

⚠️ CRITICAL: Gene/Protein Identification Context

Target Gene/Protein Identity (from UniProt):

MANDATORY VERIFICATION STEPS:

If Gene Symbol is Ambiguous or You Cannot Find Relevant Literature:

Research Target:

Citations

📄 View Raw YAML