Existing Annotations Review

GO Term	Evidence	Action	Reason
GO:0031012 extracellular matrix	IBA GO_REF:0000033	ACCEPT	Summary: SPOCK2 is a secreted proteoglycan that localizes to the extracellular matrix. UniProt annotation confirms "Secreted, extracellular space, extracellular matrix" and PMID:10386950 describes it as an ECM proteoglycan. This is a core cellular component annotation for SPOCK2. Reason: Well-supported ECM localization by both phylogenetic inference (IBA) and experimental evidence. This represents the primary subcellular localization of this secreted proteoglycan and is essential for its biological function. Supporting Evidence: PMID:10386950 We have screened a human cDNA library using an expressed sequence tag related to the BM-40/secreted protein, acidic and rich in cysteine (SPARC)/osteonectin family of proteins and isolated a novel cDNA. It encodes a protein precursor of 424 amino acids that consists of a signal peptide, a follistatin-like domain, a Ca2+-binding domain, a thyroglobulin-like domain, and a C-terminal region with two putative glycosaminoglycan attachment sites. file:human/SPOCK2/SPOCK2-deep-research-falcon.md model: Edison Scientific Literature
GO:0008191 metalloendopeptidase inhibitor activity	IBA GO_REF:0000033	MODIFY	Summary: This annotation requires careful consideration. While SPOCK2 contains a Kazal-like domain (known for protease inhibition), PMID:12810672 shows that testican-2 uniquely LACKS the MT-MMP inhibitory activity of other testican family members. Instead, it acts as a counter-inhibitor by binding to and inactivating other testicans that DO inhibit metalloendopeptidases. The Kazal domain may retain some direct inhibitory activity, but the dominant biological function is abrogating inhibition by other testicans. Reason: The term is misleading because it suggests direct metalloendopeptidase inhibition as the primary function. However, PMID:12810672 demonstrates that SPOCK2's unique role is to ABOLISH inhibition of MT-MMPs by binding to other testican family members. A more accurate annotation would be "negative regulation of endopeptidase activity" or "regulation of metalloendopeptidase activity" to capture this counter-regulatory function. Proposed replacements: negative regulation of endopeptidase activity endopeptidase regulator activity Supporting Evidence: PMID:12810672 The inhibitory function is common among testican family members except for testican 2, which was shown to uniquely abolish inhibition of MT1-MMP- or MT3-MMP-mediated pro-MMP-2 activation by other testican family members. Testican 2 inactivates N-Tes by binding to the COOH-terminal extracellular calcium-binding domain of N-Tes through its NH(2)-terminal unique domain
GO:0010810 regulation of cell-substrate adhesion	IBA GO_REF:0000033	ACCEPT	Summary: SPOCK2 modulates cell-substrate adhesion through its effects on the ECM and by regulating MT-MMP activity. PMID:12810672 demonstrates that testican-2 promotes cell motility on collagen by abrogating the inhibitory effects of other testican family members on MT1-MMP, which is essential for cell migration on ECM substrates. This represents a core regulatory function. Reason: Well-supported by phylogenetic inference and experimental evidence showing that SPOCK2 regulates cell-substrate interactions through modulation of MT-MMP activity. Cell migration on collagen (cell-substrate adhesion) was directly demonstrated to depend on testican-2's counter-inhibitory function. Supporting Evidence: PMID:12810672 Migration of U251 cells on collagen, which was dependent on MT1-MMP activity under serum-free condition, was inhibited by N-Tes or N-Tes-Delta 122 deposited on collagen.
GO:0005615 extracellular space	IBA GO_REF:0000033	ACCEPT	Summary: SPOCK2 is a secreted protein that localizes to the extracellular space, specifically to the extracellular matrix. UniProt confirms secretion and ECM localization. This is accurate but somewhat redundant with the more specific GO:0031012 (extracellular matrix) annotation. Reason: Correct localization annotation supported by phylogenetic inference and direct evidence. While broader than "extracellular matrix", it is still accurate and represents the primary cellular compartment where SPOCK2 functions. Both annotations are valid.
GO:0005509 calcium ion binding	IBA GO_REF:0000033	ACCEPT	Summary: SPOCK2 contains EC (extracellular) calcium-binding domains and calcium binding was experimentally demonstrated by PMID:10386950 using circular dichroism spectroscopy showing reversible calcium-dependent conformational changes. This is a core molecular function annotation with strong experimental support. Reason: Calcium ion binding is experimentally verified (IDA in PMID:10386950) and supported by phylogenetic inference. The protein contains canonical EF-hand calcium-binding domains and calcium binding is essential for its structural conformation and interactions with other testican family members. Supporting Evidence: PMID:10386950 A recombinant fragment consisting of the Ca2+-binding EF-hand domain and the thyroglobulin-like domain of testican-2 showed a reversible Ca2+-dependent conformational change in circular dichroism studies.
GO:0005509 calcium ion binding	IEA GO_REF:0000002	ACCEPT	Summary: Duplicate annotation for calcium ion binding based on InterPro domain assignment (IPR019577 SPARC/Testican Ca-binding domain). This is redundant with the IBA and IDA annotations for the same term but provides independent computational support. Reason: While duplicate, this IEA annotation from InterPro domain analysis provides additional independent evidence for calcium binding function. It is acceptable to have multiple evidence codes supporting the same well-established function.
GO:0008191 metalloendopeptidase inhibitor activity	IEA GO_REF:0000117	MODIFY	Summary: This IEA annotation from ARBA machine learning is based on the Kazal-like domain, which typically confers protease inhibitor activity. However, functional studies show that testican-2 LACKS the MT-MMP inhibitory activity characteristic of other testican family members and instead acts as a counter-inhibitor. Reason: Same issue as the IBA annotation for GO:0008191. The computational prediction is reasonable based on domain content but contradicts experimental evidence showing SPOCK2's unique counter-inhibitory function. Should be replaced with regulatory terms. Proposed replacements: negative regulation of endopeptidase activity endopeptidase regulator activity Supporting Evidence: PMID:12810672 The inhibitory function is common among testican family members except for testican 2, which was shown to uniquely abolish inhibition of MT1-MMP- or MT3-MMP-mediated pro-MMP-2 activation by other testican family members.
GO:0005539 glycosaminoglycan binding	IEA GO_REF:0000107	MODIFY	Summary: SPOCK2 IS a proteoglycan with chondroitin sulfate and heparan sulfate GAG chains attached. However, "glycosaminoglycan binding" suggests binding to GAGs as ligands rather than CARRYING GAGs as post-translational modifications. UniProt states SPOCK2 "Contains chondroitin sulfate and heparan sulfate O-linked oligosaccharides" indicating it IS a GAG-modified proteoglycan. Reason: The term is misleading. SPOCK2 is not primarily a GAG-binding protein but rather a GAG-carrying proteoglycan. The more appropriate annotation would be related to proteoglycan core protein function or ECM structural molecule activity. While SPOCK2 may have some GAG-binding activity, the dominant characteristic is being a proteoglycan itself. Proposed replacements: extracellular matrix structural constituent
GO:0050840 extracellular matrix binding	IEA GO_REF:0000107	ACCEPT	Summary: SPOCK2 is an ECM proteoglycan that likely interacts with other ECM components. PMID:12810672 shows testican-2 binds to N-Tes (testican-3) deposited on collagen, demonstrating ECM protein-protein interactions. As an ECM structural component itself, SPOCK2 would be expected to bind to ECM. Reason: Reasonable inference from orthology. SPOCK2 is an ECM proteoglycan that interacts with other ECM proteins including other testican family members and likely collagen and other matrix components. This represents a legitimate molecular function even though it is computationally predicted. Supporting Evidence: PMID:12810672 Testican 2 was not incorporated into collagen by itself, and was deposited only in the presence of N-Tes, suggesting that testican 2 binds to N-Tes deposited on collagen.
GO:0005515 protein binding	IPI PMID:32296183 A reference map of the human binary protein interactome.	REMOVE	Summary: Generic protein binding annotation from a high-throughput interactome study showing interaction with ENKD1 (Q9H0I2). While technically correct, this provides minimal functional information as most proteins bind other proteins. The more informative binding activities are the specific interactions with other testican family members. Reason: Following curation guidelines: "Avoid the term protein binding, this doesn't tell us anything about the actual function." This is a generic annotation from a binary interactome screen that provides no meaningful functional insight. More specific binding annotations (ECM binding, interactions with testicans) are more informative. Supporting Evidence: PMID:32296183 Apr 8. A reference map of the human binary protein interactome.
GO:0008191 metalloendopeptidase inhibitor activity	TAS PMID:12810672 Testican 2 abrogates inhibition of membrane-type matrix meta...	MODIFY	Summary: This TAS annotation from PMID:12810672 is actually CONTRADICTED by the same paper. The paper explicitly states that testican-2 LACKS the inhibitory function common to other testican family members and instead ABOLISHES inhibition of MT-MMPs. This appears to be a mis-curation. Reason: The cited paper PMID:12810672 demonstrates the opposite - that testican-2 uniquely lacks MT-MMP inhibitory activity and instead acts as a counter-inhibitor. This is a clear example of mis-annotation where the evidence actually contradicts the assigned term. Should be replaced with regulatory terms reflecting the actual function. Proposed replacements: negative regulation of endopeptidase activity positive regulation of cell motility Supporting Evidence: PMID:12810672 The inhibitory function is common among testican family members except for testican 2, which was shown to uniquely abolish inhibition of MT1-MMP- or MT3-MMP-mediated pro-MMP-2 activation by other testican family members.
GO:2000147 positive regulation of cell motility	TAS PMID:12810672 Testican 2 abrogates inhibition of membrane-type matrix meta...	ACCEPT	Summary: PMID:12810672 directly demonstrates that testican-2 promotes cell migration on collagen by abrogating the inhibitory effects of other testican family members on MT1-MMP activity. This is a well-supported core biological process annotation. Reason: Strong experimental support from PMID:12810672 showing that SPOCK2 positively regulates cell motility through its unique counter-inhibitory mechanism. Cell migration assays demonstrated that testican-2 expression allowed migration of MT1-MMP-expressing cells on collagen that was otherwise blocked by other testicans. Supporting Evidence: PMID:12810672 Migration of U251 cells on collagen, which was dependent on MT1-MMP activity under serum-free condition, was inhibited by N-Tes or N-Tes-Delta 122 deposited on collagen.
GO:0005509 calcium ion binding	IDA PMID:10386950 Molecular cloning of testican-2: defining a novel calcium-bi...	ACCEPT	Summary: This is the gold-standard experimental demonstration of calcium binding by SPOCK2 using circular dichroism spectroscopy. PMID:10386950 showed reversible calcium-dependent conformational changes in a recombinant fragment containing the EF-hand calcium-binding domain. This is a third annotation for the same term with direct experimental evidence. Reason: Strong experimental evidence (IDA) from the original characterization paper. This represents direct biochemical demonstration of calcium binding activity and is a core molecular function. While duplicate with other calcium binding annotations, this has the strongest evidence code (IDA) and should be retained. Supporting Evidence: PMID:10386950 A recombinant fragment consisting of the Ca2+-binding EF-hand domain and the thyroglobulin-like domain of testican-2 showed a reversible Ca2+-dependent conformational change in circular dichroism studies.
GO:0007416 synapse assembly	NAS PMID:10386950 Molecular cloning of testican-2: defining a novel calcium-bi...	KEEP AS NON CORE	Summary: PMID:10386950 states that testican-2 has "the potential to participate in diverse steps of neurogenesis" based on its brain expression pattern and domain structure, but does not provide direct evidence for synapse assembly. This is inferred from expression in neurons and similarity to other neuronal ECM proteins. The evidence is quite indirect. Reason: While SPOCK2 is highly expressed in brain and may contribute to neurogenesis, there is no direct experimental evidence for synapse assembly specifically. The NAS evidence code indicates this is inferred from expression pattern and general neurogenesis potential. This represents a plausible but peripheral function compared to the core ECM/proteoglycan and cell motility regulation activities that are experimentally demonstrated. Supporting Evidence: PMID:10386950 Testican-1 and -2 form a novel Ca2+-binding proteoglycan family built of modular domains with the potential to participate in diverse steps of neurogenesis.
GO:0030198 extracellular matrix organization	NAS PMID:10386950 Molecular cloning of testican-2: defining a novel calcium-bi...	ACCEPT	Summary: As an ECM proteoglycan, SPOCK2 is a structural component of the extracellular matrix and contributes to ECM organization. PMID:10386950 characterizes it as an ECM proteoglycan with modular domains typical of ECM structural proteins. PMID:12810672 shows it modulates ECM-mediated cell migration. This is a core biological process. Reason: Well-supported core function. SPOCK2 is an ECM structural proteoglycan that participates in ECM organization both as a structural component and through regulation of ECM remodeling via its effects on MT-MMP activity. While the NAS evidence from PMID:10386950 is based on structure and localization, the function is further supported by PMID:12810672 showing ECM-dependent effects. Supporting Evidence: PMID:10386950 We have screened a human cDNA library using an expressed sequence tag related to the BM-40/secreted protein, acidic and rich in cysteine (SPARC)/osteonectin family of proteins [ECM proteins] PMID:12810672 Testican family proteins are putative extracellular heparan/chondroitin sulfate proteoglycans
GO:0031012 extracellular matrix	NAS PMID:10386950 Molecular cloning of testican-2: defining a novel calcium-bi...	ACCEPT	Summary: Duplicate annotation for extracellular matrix localization with NAS evidence from PMID:10386950. This is the same term as the IBA annotation reviewed earlier. Both are correct and supported. Reason: Correct ECM localization annotation with NAS evidence from the original characterization paper. Duplicate of the IBA annotation but both are valid. Multiple evidence codes for the same well-established localization are acceptable. Supporting Evidence: PMID:10386950 Molecular cloning of testican-2: defining a novel calcium-binding proteoglycan family expressed in brain.
GO:0045595 regulation of cell differentiation	NAS PMID:10386950 Molecular cloning of testican-2: defining a novel calcium-bi...	KEEP AS NON CORE	Summary: PMID:10386950 mentions "the potential to participate in diverse steps of neurogenesis" which would include regulation of neuronal cell differentiation. However, this is a very broad inference based on brain expression pattern and domain structure without direct experimental evidence for regulating differentiation. Reason: While plausible given SPOCK2's role in neurogenesis and brain development, there is no direct experimental evidence for regulation of cell differentiation. The annotation is based on inference from expression pattern and general neurogenesis potential (NAS evidence). This is a peripheral function compared to the experimentally demonstrated core activities in ECM organization and cell motility regulation. Supporting Evidence: PMID:10386950 Testican-1 and -2 form a novel Ca2+-binding proteoglycan family built of modular domains with the potential to participate in diverse steps of neurogenesis.

Core Functions

Calcium-binding proteoglycan that binds calcium ions through EF-hand domains, essential for protein conformation and interactions with other testican family members

Molecular Function:

calcium ion binding

Cellular Locations:

extracellular matrix extracellular space

Supporting Evidence:

PMID:10386950
A recombinant fragment consisting of the Ca2+-binding EF-hand domain and the thyroglobulin-like domain of testican-2 showed a reversible Ca2+-dependent conformational change in circular dichroism studies.
PMID:12810672
Testican 2 inactivates N-Tes by binding to the COOH-terminal extracellular calcium-binding domain of N-Tes through its NH(2)-terminal unique domain

Extracellular matrix structural constituent functioning as a proteoglycan with GAG chains to organize ECM structure and support cell-matrix interactions

Molecular Function:

extracellular matrix binding

Directly Involved In:

extracellular matrix organization

Cellular Locations:

extracellular matrix

Supporting Evidence:

PMID:10386950
It encodes a protein precursor of 424 amino acids that consists of a signal peptide, a follistatin-like domain, a Ca2+-binding domain, a thyroglobulin-like domain, and a C-terminal region with two putative glycosaminoglycan attachment sites.
file:human/SPOCK2/SPOCK2-uniprot.txt
Contains chondroitin sulfate and heparan sulfate O-linked oligosaccharides

Endopeptidase regulator that uniquely abrogates MT-MMP inhibition by other testican family members through direct binding, enabling ECM remodeling and cell motility

Molecular Function:

endopeptidase regulator activity

Directly Involved In:

positive regulation of cell motility regulation of cell-substrate adhesion

Cellular Locations:

extracellular matrix

Supporting Evidence:

PMID:12810672
The inhibitory function is common among testican family members except for testican 2, which was shown to uniquely abolish inhibition of MT1-MMP- or MT3-MMP-mediated pro-MMP-2 activation by other testican family members.
PMID:12810672
Migration of U251 cells on collagen, which was dependent on MT1-MMP activity under serum-free condition, was inhibited by N-Tes or N-Tes-Delta 122 deposited on collagen. Binding of testican 2 to N-Tes deposited on collagen allowed migration of cells expressing MT1-MMP.

References

GO_REF:0000002

Gene Ontology annotation through association of InterPro records with GO terms.

GO_REF:0000033

Annotation inferences using phylogenetic trees

GO_REF:0000107

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

GO_REF:0000117

Electronic Gene Ontology annotations created by ARBA machine learning models

PMID:10386950

Molecular cloning of testican-2: defining a novel calcium-binding proteoglycan family expressed in brain.

Original characterization paper defining testican-2 as a calcium-binding proteoglycan with modular domain structure

"It encodes a protein precursor of 424 amino acids that consists of a signal peptide, a follistatin-like domain, a Ca2+-binding domain, a thyroglobulin-like domain, and a C-terminal region with two putative glycosaminoglycan attachment sites."
Calcium binding was experimentally demonstrated using circular dichroism spectroscopy

"A recombinant fragment consisting of the Ca2+-binding EF-hand domain and the thyroglobulin-like domain of testican-2 showed a reversible Ca2+-dependent conformational change in circular dichroism studies."
Highly expressed in CNS with widespread neuronal expression

"A widespread expression in multiple neuronal cell types in olfactory bulb, cerebral cortex, thalamus, hippocampus, cerebellum, and medulla was detected by in situ hybridization."
Proposes potential role in neurogenesis

"Testican-1 and -2 form a novel Ca2+-binding proteoglycan family built of modular domains with the potential to participate in diverse steps of neurogenesis."

PMID:12810672

Testican 2 abrogates inhibition of membrane-type matrix metalloproteinases by other testican family proteins.

Testican-2 uniquely lacks the MT-MMP inhibitory activity of other testican family members

"The inhibitory function is common among testican family members except for testican 2, which was shown to uniquely abolish inhibition of MT1-MMP- or MT3-MMP-mediated pro-MMP-2 activation by other testican family members."
Testican-2 inactivates other testican proteins through direct binding

"Testican 2 inactivates N-Tes by binding to the COOH-terminal extracellular calcium-binding domain of N-Tes through its NH(2)-terminal unique domain as demonstrated by coimmunoprecipitation analysis"
Testican-2 promotes cell motility by abrogating testican inhibition of MT-MMPs

"Migration of U251 cells on collagen, which was dependent on MT1-MMP activity under serum-free condition, was inhibited by N-Tes or N-Tes-Delta 122 deposited on collagen."
Testican-2 binds to other testicans deposited on ECM components

"Testican 2 was not incorporated into collagen by itself, and was deposited only in the presence of N-Tes, suggesting that testican 2 binds to N-Tes deposited on collagen."
All testican family members are expressed in normal brain neurons

"In situ hybridization showed that neurons are a major source of all of the testican family members in the normal brain."

PMID:32296183

A reference map of the human binary protein interactome.

file:human/SPOCK2/SPOCK2-deep-research-falcon.md

Deep research report on SPOCK2

📚 Additional Documentation

Deep Research Falcon

(SPOCK2-deep-research-falcon.md)

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protein_family: Not specified in UniProt
protein_domains: EF-hand-dom_pair. (IPR011992); Kazal_dom. (IPR002350); Kazal_dom_sf.
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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: Q92563
Protein Description: RecName: Full=Testican-2; AltName: Full=SPARC/osteonectin, CWCV, and Kazal-like domains proteoglycan 2; Flags: Precursor;
Gene Information: Name=SPOCK2; Synonyms=KIAA0275, TICN2; ORFNames=UNQ269/PRO306;
Organism (full): Homo sapiens (Human).
Protein Family: Not specified in UniProt
Key Domains: EF-hand-dom_pair. (IPR011992); Kazal_dom. (IPR002350); Kazal_dom_sf. (IPR036058); SPARC/Testican_Ca-bd-dom. (IPR019577); Thyroglobulin_1. (IPR000716)

MANDATORY VERIFICATION STEPS:

Check if the gene symbol "SPOCK2" 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 'SPOCK2' 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 SPOCK2 (gene ID: SPOCK2, UniProt: Q92563) 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: Q92563
Protein Description: RecName: Full=Testican-2; AltName: Full=SPARC/osteonectin, CWCV, and Kazal-like domains proteoglycan 2; Flags: Precursor;
Gene Information: Name=SPOCK2; Synonyms=KIAA0275, TICN2; ORFNames=UNQ269/PRO306;
Organism (full): Homo sapiens (Human).
Protein Family: Not specified in UniProt
Key Domains: EF-hand-dom_pair. (IPR011992); Kazal_dom. (IPR002350); Kazal_dom_sf. (IPR036058); SPARC/Testican_Ca-bd-dom. (IPR019577); Thyroglobulin_1. (IPR000716)

MANDATORY VERIFICATION STEPS:

Check if the gene symbol "SPOCK2" 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 SPOCK2 (gene ID: SPOCK2, UniProt: Q92563) 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 and target verification
- Identity: The target is human SPOCK2 (UniProt Q92563), also known as Testican‑2, a secreted extracellular matrix (ECM) proteoglycan precursor of 424 amino acids. Literature and reviews confirm SPOCK2/Testican‑2 nomenclature and human origin (Homo sapiens) (xiao2024spockmasterregulator pages 2-4, ngo2020circulatingtestican2is pages 5-6). Domain architecture matches UniProt/IPR annotations: an N‑terminal signal peptide; a follistatin‑like (FS) domain; a Ca2+‑binding EC domain containing two EF‑hand motifs; a thyroglobulin type‑1 (TY) domain; and a C‑terminal acidic tail with glycosaminoglycan (GAG) attachment/binding sites (heparan/chondroitin sulfate) (xiao2024spockmasterregulator pages 2-4, ren2020spock2affectsthe pages 1-2). No conflicting gene symbol usage was found in other organisms for the sources cited here.

1) Key concepts and definitions
- Molecular identity and domains: SPOCK2/Testican‑2 is a secreted ECM‑associated proteoglycan with multidomain architecture (FS, EF‑hand pair, TY) and C‑terminal GAG attachment sites. These features place it within the BM‑40/SPARC family of matricellular proteins that bind GAGs and modulate extracellular protease activity and cell–matrix signaling (Review: Molecular Medicine Reports, 2024; https://doi.org/10.3892/mmr.2024.13355) (xiao2024spockmasterregulator pages 2-4). Ren et al. describe the same domain set and GAG‑attachment in the acidic C‑terminus (Reproductive Sciences, 2020; https://doi.org/10.1007/s43032-020-00197-4) (ren2020spock2affectsthe pages 1-2).
- Primary biochemical class: SPOCK2 is not an enzyme or transporter; it is a secreted proteoglycan that functions as an ECM structural/regulatory component and signaling modulator, notably influencing matrix metalloproteinase (MMP) pathways (ren2020spock2affectsthe pages 1-2, ngo2020circulatingtestican2is pages 5-6).

2) Function and interaction partners (current understanding)
- MMP axis regulation: Multiple studies indicate SPOCK2 modulates the MT1‑MMP (MMP14)/MMP‑2 axis and downstream MMP‑2 activity.
• In human endometrial cancer cells, SPOCK2 upregulation inhibited MT1‑MMP and MMP‑2 expression and reduced pro‑MMP‑2 activation, concomitant with reduced invasion/migration (Reproductive Sciences, 2020; https://doi.org/10.1007/s43032-020-00197-4) (ren2020spock2affectsthe pages 1-2, ren2020spock2affectsthe pages 9-9).
• In a rat neuropathic pain model, SPOCK2 was increased in spinal astrocytes; SPOCK2 interacted with MT1‑MMP and regulated MMP‑2 activation via the SPARC extracellular domain, promoting ERK1/2 activation and IL‑1β production; SPOCK2 knockdown partially relieved pain behaviors (Journal of Neuroinflammation, 2024; https://doi.org/10.1186/s12974-024-03051-5) (wang2024spock2modulatesneuropathic pages 1-2).
• In human kidney contexts, testican‑2 increased MMP‑2/MMP‑9 activity in glomerular endothelial cell supernatants and enhanced endothelial tube formation/migration in vitro, consistent with ECM protease modulation (PNAS, 2020; https://doi.org/10.1073/pnas.2009606117) (ngo2020circulatingtestican2is pages 5-6, ngo2020circulatingtestican2is pages 6-7).
- Position in signaling: Through modulation of MT1‑MMP/MMP‑2 and related proteolysis, SPOCK2 influences ECM remodeling, cell invasion/migration, and inflammatory signaling (ERK1/2, IL‑1β in astrocytes), i.e., a matricellular signaling modulator rather than a catalytic enzyme (wang2024spock2modulatesneuropathic pages 1-2, ren2020spock2affectsthe pages 1-2, ngo2020circulatingtestican2is pages 5-6).

3) Localization and post‑translational modifications
- Localization: SPOCK2 is secreted to the extracellular space and integrates with basement membranes and interstitial ECM. In human kidney, immunogold EM localized testican‑2 to podocyte foot processes, the glomerular basement membrane (GBM), and the GBM–endothelial interface; single‑nucleus RNA‑seq showed SPOCK2 expression confined to podocytes (PNAS, 2020; https://doi.org/10.1073/pnas.2009606117) (ngo2020circulatingtestican2is pages 3-5, ngo2020circulatingtestican2is pages 5-6).
- Proteoglycan features: SPOCK2 carries GAG chains; the protein has C‑terminal GAG attachment/binding sites, consistent with heparan/chondroitin sulfate decoration typical of SPOCK/testican family members (Review, 2024; https://doi.org/10.3892/mmr.2024.13355; Ren 2020; https://doi.org/10.1007/s43032-020-00197-4) (xiao2024spockmasterregulator pages 2-4, ren2020spock2affectsthe pages 1-2).

4) Pathways and processes with quantitative evidence
- Kidney podocyte biology and vascular crosstalk:
• Physiology: In renal arteriovenous sampling of 22 individuals, arterial‑to‑renal‑venous gradients showed testican‑2 increases across the kidney, indicating renal release; circulating testican‑2 was positively associated with eGFR in two cohorts (JHS n=1,928; FHS n=1,621) and with slower eGFR decline (JHS slope β=0.38, P=4.8×10⁻⁶; FHS β=0.45, P=1.1×10⁻¹⁵). In participants with baseline eGFR ≥60, higher testican‑2 associated with lower incident CKD risk (JHS OR 0.70, 95% CI 0.55–0.90, P=0.005; FHS HR 0.83, 95% CI 0.69–1.00, P=0.046). Functionally, testican‑2 increased HGE cell tube formation and migration in vitro, additively with VEGF (PNAS, 2020; https://doi.org/10.1073/pnas.2009606117) (ngo2020circulatingtestican2is pages 3-5, ngo2020circulatingtestican2is pages 6-7).
- Cancer biology (ECM remodeling):
• Endometrial cancer: SPOCK2 overexpression reduced invasion/migration and MT1‑MMP/MMP‑2 expression/activation (Reproductive Sciences, 2020; https://doi.org/10.1007/s43032-020-00197-4) (ren2020spock2affectsthe pages 1-2, ren2020spock2affectsthe pages 9-9).
• High‑grade serous ovarian cancer (HGSOC): SPOCK2 upregulated vs. normal; diagnostic AUC 0.894 (CI 0.865–0.923); high SPOCK2 associated with shorter OS (HR 1.45, P=0.005); correlated with ECM/focal adhesion pathways and distinct immune infiltration patterns (Frontiers in Genetics, 2022; https://doi.org/10.3389/fgene.2022.878123) (jiao2022clinicalsignificanceof pages 9-12).
• Lung adenocarcinoma (LUAD): EZH2 epigenetically represses SPOCK2; EZH2 inhibitor tazemetostat (1–2 μM) restored SPOCK2 mRNA/protein; SPOCK2 overexpression suppressed proliferation, migration, invasion in A549/HCC827, and slowed tumor growth in vivo (Human Cell, 2023; https://doi.org/10.1007/s13577-023-00855-0) (liu2023spock2andspred1 pages 4-7).
- Neuroinflammation/neuropathic pain:
• In rat CCI, SPOCK2 was upregulated in spinal astrocytes, interacted with MT1‑MMP to regulate MMP‑2 activation, and promoted ERK1/2 and IL‑1β; siRNA against SPOCK2 alleviated pain hypersensitivity (Journal of Neuroinflammation, 2024; https://doi.org/10.1186/s12974-024-03051-5) (wang2024spock2modulatesneuropathic pages 1-2).

5) Recent developments and applications (prioritizing 2023–2024)
- Epigenetic targeting in LUAD: SPOCK2 and SPRED1 are repressed by EZH2; pharmacologic EZH2 inhibition (tazemetostat) restored SPOCK2 expression and anticancer phenotypes in vitro/in vivo, suggesting a therapeutic avenue to re‑engage SPOCK2’s tumor‑suppressive ECM signaling (Human Cell, 2023; https://doi.org/10.1007/s13577-023-00855-0) (liu2023spock2andspred1 pages 4-7).
- Neuropathic pain mechanism: Astrocytic SPOCK2‑MT1‑MMP interaction upstream of MMP‑2/ERK1/2/IL‑1β points to a glial ECM‑signaling axis as a potential modulator of pain; SPOCK2 knockdown reduced pain in vivo (Journal of Neuroinflammation, 2024; https://doi.org/10.1186/s12974-024-03051-5) (wang2024spock2modulatesneuropathic pages 1-2).
- Kidney biomarker and podocyte biology: Circulating testican‑2 serves as a podocyte‑derived marker of kidney health with strong, reproducible associations with eGFR slope and incident CKD across cohorts, motivating its use in renal risk stratification (PNAS, 2020; https://doi.org/10.1073/pnas.2009606117) (ngo2020circulatingtestican2is pages 3-5).

6) Expert opinions and reviews
- A 2024 narrative review synthesizes SPOCK family structure and function, emphasizing SPOCK2’s secreted proteoglycan identity, domain architecture (FS, EF‑hand, TY) and participation in ECM and neurodevelopmental contexts; it notes tissue enrichment in lung, brain, kidney, and potential cathepsin interactions via TY domain by analogy within the family (Molecular Medicine Reports, 2024; https://doi.org/10.3892/mmr.2024.13355) (xiao2024spockmasterregulator pages 2-4).

7) Tissue and cell‑type expression maps
- Kidney: snRNA‑seq shows SPOCK2 expression restricted to podocytes in healthy human kidney; protein localizes to podocyte foot processes and GBM by EM/IHC (PNAS, 2020; https://doi.org/10.1073/pnas.2009606117) (ngo2020circulatingtestican2is pages 3-5, ngo2020circulatingtestican2is pages 5-6).
- Broader tissues: Review notes relatively high expression in lung and detectable levels in brain, adrenal gland, kidney, lymphoid tissues, testes, consistent with a widely expressed ECM proteoglycan with tissue‑specific roles (Molecular Medicine Reports, 2024; https://doi.org/10.3892/mmr.2024.13355) (xiao2024spockmasterregulator pages 2-4).

8) Consolidated artifact of recent studies
| Year | Study (first author) | System / Context | Key finding | Quantitative / statistical highlights | URL / DOI |
|---|---|---|---|---:|---|
| 2024 | Wang et al. | Rat neuropathic pain (spinal cord, CCI model) | SPOCK2 upregulated in spinal astrocytes; interacts with MT1‑MMP to regulate MMP‑2 activation, astrocytic ERK1/2 and IL‑1β; SPOCK2 knockdown (siRNA) partially reduces pain behaviors | Expression markedly increased after CCI; siRNA knockdown produced partial alleviation of pain in behavioral assays (authors report significant effect) (wang2024spock2modulatesneuropathic pages 1-2) | https://doi.org/10.1186/s12974-024-03051-5 (wang2024spock2modulatesneuropathic pages 1-2) |
| 2023 | Liu et al. | Lung adenocarcinoma (cell lines, TCGA analysis) | EZH2 epigenetically represses SPOCK2 (H3K27me3); EZH2 inhibitor tazemetostat restores SPOCK2; SPOCK2 overexpression suppresses proliferation, migration, invasion in vitro and tumor growth in vivo | Tazemetostat (1–2 µM) increased SPOCK2 mRNA/protein (n=3; multiple assays P < 0.01); higher SPOCK2 correlated with better survival in TCGA LUAD (liu2023spock2andspred1 pages 4-7) | https://doi.org/10.1007/s13577-023-00855-0 (liu2023spock2andspred1 pages 4-7) |
| 2022 | Jiao et al. | High‑grade serous ovarian cancer (HGSOC; bulk & bioinformatics) | SPOCK2 is upregulated in HGSOC; associated with ECM-related pathways and immune cell infiltration; higher SPOCK2 relates to poorer prognosis | Diagnostic AUC = 0.894 (CI 0.865–0.923); high SPOCK2 mRNA associated with worse OS (HR = 1.45, p = 0.005) (jiao2022clinicalsignificanceof pages 9-12) | https://doi.org/10.3389/fgene.2022.878123 (jiao2022clinicalsignificanceof pages 9-12) |
| 2020 | Ngo et al. | Human kidney / podocytes (cohorts JHS, FHS + kidney tissue) | SPOCK2 (testican‑2) is podocyte‑derived, localizes to podocyte foot processes and GBM; increases MMP‑2/9 activity and promotes glomerular endothelial tube formation/migration; circulating testican‑2 positively associates with kidney health | JHS eGFR slope: β = 0.38, P = 4.8×10⁻⁶; FHS β = 0.45, P = 1.1×10⁻¹⁵; incident CKD (baseline eGFR ≥60): JHS OR = 0.70 (95% CI 0.55–0.90), P = 0.005; (cohorts n≈1,928 & 1,621) (ngo2020circulatingtestican2is pages 3-5) | https://doi.org/10.1073/pnas.2009606117 (ngo2020circulatingtestican2is pages 3-5) |
| 2020 | Ren et al. | Endometrial cancer (cell lines, tissue IHC) | SPOCK2 upregulation inhibits cell proliferation, invasion, adhesion and reduces MT1‑MMP and MMP‑2 expression/activation, limiting invasive behavior | Upregulation reduced invasion/migration and inhibited MT1‑MMP/MMP‑2 activation in vitro (statistically significant effects reported by authors) (ren2020spock2affectsthe pages 1-2) | https://doi.org/10.1007/s43032-020-00197-4 (ren2020spock2affectsthe pages 1-2) |
| 2024 | Xiao et al. (Review) | SPOCK family (multi‑tissue review) | Summarizes SPOCK2 domain architecture: N‑terminal unique region, follistatin‑like (FS) domain, Ca²⁺‑binding EC domain with two EF‑hands, thyroglobulin type‑1 (TY) domain, C‑terminal GAG attachment sites; secreted proteoglycan binding GAGs; tissue distribution (lung, brain, kidney, etc.) | Domain annotation and tissue expression summarized across studies (review synthesis) (xiao2024spockmasterregulator pages 2-4) | https://doi.org/10.3892/mmr.2024.13355 (xiao2024spockmasterregulator pages 2-4) |

Table: Compact table summarizing key 2020–2024 studies on human SPOCK2 (Testican‑2): context, main findings, quantitative highlights, and DOIs with supporting context citations for follow-up.

Conclusions and knowledge gaps
- Primary role: SPOCK2/Testican‑2 is a secreted proteoglycan that modulates ECM protease activity (MT1‑MMP/MMP‑2) and cell–matrix signaling. It is not an enzyme or transporter; rather, it acts as a matricellular regulator at the extracellular face of cells where it is deposited (ren2020spock2affectsthe pages 1-2, wang2024spock2modulatesneuropathic pages 1-2, ngo2020circulatingtestican2is pages 5-6).
- Location: Extracellular/ECM and basement membranes, exemplified in human glomerulus (podocyte foot processes and GBM) (ngo2020circulatingtestican2is pages 3-5, ngo2020circulatingtestican2is pages 5-6).
- Pathways: ECM remodeling and endothelial–podocyte crosstalk in kidney; ECM‑dependent invasion and immune interactions in cancers; glial ECM‑signaling in neuropathic pain (ngo2020circulatingtestican2is pages 3-5, jiao2022clinicalsignificanceof pages 9-12, liu2023spock2andspred1 pages 4-7, wang2024spock2modulatesneuropathic pages 1-2).
- 2023–2024 highlights: EZH2–SPOCK2 axis in LUAD provides a mechanistic and therapeutic entry point; astrocytic SPOCK2–MT1‑MMP–MMP‑2–ERK–IL‑1β axis in neuropathic pain suggests new targets; review consolidates SPOCK2 structure and tissue distribution (liu2023spock2andspred1 pages 4-7, wang2024spock2modulatesneuropathic pages 1-2, xiao2024spockmasterregulator pages 2-4).
- Open questions: Precise in vivo substrates/partners across tissues; structural basis of MT1‑MMP binding; GAG chain composition and its regulation; whether modulating SPOCK2 therapeutically is safe/effective in humans.

References with URLs and publication dates
- Ngo D et al. Circulating testican‑2 is a podocyte‑derived marker of kidney health. PNAS. Sep 2020. https://doi.org/10.1073/pnas.2009606117 (ngo2020circulatingtestican2is pages 3-5, ngo2020circulatingtestican2is pages 6-7, ngo2020circulatingtestican2is pages 5-6).
- Ren F et al. SPOCK2 affects the biological behavior of endometrial cancer cells by regulation of MT1‑MMP and MMP2. Reproductive Sciences. May 2020. https://doi.org/10.1007/s43032-020-00197-4 (ren2020spock2affectsthe pages 1-2, ren2020spock2affectsthe pages 9-9).
- Jiao M et al. Clinical significance of SPOCK2 expression signature for HGSOC. Frontiers in Genetics. Sep 2022. https://doi.org/10.3389/fgene.2022.878123 (jiao2022clinicalsignificanceof pages 9-12).
- Liu Y et al. SPOCK2 and SPRED1 function downstream of EZH2 in LUAD. Human Cell. Jan 2023. https://doi.org/10.1007/s13577-023-00855-0 (liu2023spock2andspred1 pages 4-7).
- Wang C et al. SPOCK2 modulates neuropathic pain via MT1‑MMP/MMP‑2 in astrocytes. Journal of Neuroinflammation. Feb 2024. https://doi.org/10.1186/s12974-024-03051-5 (wang2024spock2modulatesneuropathic pages 1-2).
- Xiao M et al. SPOCK: Master regulator of malignant tumors (Review). Molecular Medicine Reports. Oct 2024. https://doi.org/10.3892/mmr.2024.13355 (xiao2024spockmasterregulator pages 2-4).

References

(xiao2024spockmasterregulator pages 2-4): Mingyuan Xiao, Jiancheng Xue, and Enli Jin. Spock: master regulator of malignant tumors (review). Molecular Medicine Reports, Oct 2024. URL: https://doi.org/10.3892/mmr.2024.13355, doi:10.3892/mmr.2024.13355. This article has 9 citations and is from a peer-reviewed journal.
(ngo2020circulatingtestican2is pages 5-6): Debby Ngo, Donghai Wen, Yan Gao, Michelle J. Keyes, Erika R. Drury, Dan H. Katz, Mark D. Benson, Sumita Sinha, Dongxiao Shen, Laurie A. Farrell, Bennet D. Peterson, David J. Friedman, Sammy Elmariah, Bessie A. Young, J. Gustav Smith, Qiong Yang, Ramachandran S. Vasan, Martin G. Larson, Adolfo Correa, Benjamin D. Humphreys, Thomas J. Wang, Martin R. Pollak, James G. Wilson, Robert E. Gerszten, and Eugene P. Rhee. Circulating testican-2 is a podocyte-derived marker of kidney health. Proceedings of the National Academy of Sciences, 117:25026-25035, Sep 2020. URL: https://doi.org/10.1073/pnas.2009606117, doi:10.1073/pnas.2009606117. This article has 36 citations and is from a highest quality peer-reviewed journal.
(ren2020spock2affectsthe pages 1-2): Fang Ren, Dan-bo Wang, Yizi Wang, Peng Chen, and Cuishan Guo. Spock2 affects the biological behavior of endometrial cancer cells by regulation of mt1-mmp and mmp2. Reproductive Sciences, 27:1391-1399, May 2020. URL: https://doi.org/10.1007/s43032-020-00197-4, doi:10.1007/s43032-020-00197-4. This article has 34 citations and is from a peer-reviewed journal.
(ren2020spock2affectsthe pages 9-9): Fang Ren, Dan-bo Wang, Yizi Wang, Peng Chen, and Cuishan Guo. Spock2 affects the biological behavior of endometrial cancer cells by regulation of mt1-mmp and mmp2. Reproductive Sciences, 27:1391-1399, May 2020. URL: https://doi.org/10.1007/s43032-020-00197-4, doi:10.1007/s43032-020-00197-4. This article has 34 citations and is from a peer-reviewed journal.
(wang2024spock2modulatesneuropathic pages 1-2): Chenglong Wang, Yitong Xu, Miao Xu, Cong Sun, Xiaojiao Zhang, Xueshu Tao, and Tao Song. Spock2 modulates neuropathic pain by interacting with mt1-mmp to regulate astrocytic mmp-2 activation in rats with chronic constriction injury. Journal of Neuroinflammation, Feb 2024. URL: https://doi.org/10.1186/s12974-024-03051-5, doi:10.1186/s12974-024-03051-5. This article has 10 citations and is from a peer-reviewed journal.
(ngo2020circulatingtestican2is pages 6-7): Debby Ngo, Donghai Wen, Yan Gao, Michelle J. Keyes, Erika R. Drury, Dan H. Katz, Mark D. Benson, Sumita Sinha, Dongxiao Shen, Laurie A. Farrell, Bennet D. Peterson, David J. Friedman, Sammy Elmariah, Bessie A. Young, J. Gustav Smith, Qiong Yang, Ramachandran S. Vasan, Martin G. Larson, Adolfo Correa, Benjamin D. Humphreys, Thomas J. Wang, Martin R. Pollak, James G. Wilson, Robert E. Gerszten, and Eugene P. Rhee. Circulating testican-2 is a podocyte-derived marker of kidney health. Proceedings of the National Academy of Sciences, 117:25026-25035, Sep 2020. URL: https://doi.org/10.1073/pnas.2009606117, doi:10.1073/pnas.2009606117. This article has 36 citations and is from a highest quality peer-reviewed journal.
(ngo2020circulatingtestican2is pages 3-5): Debby Ngo, Donghai Wen, Yan Gao, Michelle J. Keyes, Erika R. Drury, Dan H. Katz, Mark D. Benson, Sumita Sinha, Dongxiao Shen, Laurie A. Farrell, Bennet D. Peterson, David J. Friedman, Sammy Elmariah, Bessie A. Young, J. Gustav Smith, Qiong Yang, Ramachandran S. Vasan, Martin G. Larson, Adolfo Correa, Benjamin D. Humphreys, Thomas J. Wang, Martin R. Pollak, James G. Wilson, Robert E. Gerszten, and Eugene P. Rhee. Circulating testican-2 is a podocyte-derived marker of kidney health. Proceedings of the National Academy of Sciences, 117:25026-25035, Sep 2020. URL: https://doi.org/10.1073/pnas.2009606117, doi:10.1073/pnas.2009606117. This article has 36 citations and is from a highest quality peer-reviewed journal.
(jiao2022clinicalsignificanceof pages 9-12): Minjie Jiao, Wenbo Sun, Lina Li, Chunyan Li, Jing Zhou, Qian Li, and L. Duan. Clinical significance of spock2 expression signature for high-grade serous ovarian cancer patients. Frontiers in Genetics, Sep 2022. URL: https://doi.org/10.3389/fgene.2022.878123, doi:10.3389/fgene.2022.878123. This article has 8 citations and is from a peer-reviewed journal.
(liu2023spock2andspred1 pages 4-7): Yang Liu, Xiaoxi Fan, Changrui Jiang, and Shun Xu. Spock2 and spred1 function downstream of ezh2 to impede the malignant progression of lung adenocarcinoma in vitro and in vivo. Human Cell, 36:812-821, Jan 2023. URL: https://doi.org/10.1007/s13577-023-00855-0, doi:10.1007/s13577-023-00855-0. This article has 10 citations and is from a peer-reviewed journal.

Citations

xiao2024spockmasterregulator pages 2-4
jiao2022clinicalsignificanceof pages 9-12
https://doi.org/10.3892/mmr.2024.13355
https://doi.org/10.1007/s43032-020-00197-4
https://doi.org/10.1186/s12974-024-03051-5
https://doi.org/10.1073/pnas.2009606117
https://doi.org/10.3892/mmr.2024.13355;
https://doi.org/10.3389/fgene.2022.878123
https://doi.org/10.1007/s13577-023-00855-0
https://doi.org/10.3892/mmr.2024.13355,
https://doi.org/10.1073/pnas.2009606117,
https://doi.org/10.1007/s43032-020-00197-4,
https://doi.org/10.1186/s12974-024-03051-5,
https://doi.org/10.3389/fgene.2022.878123,
https://doi.org/10.1007/s13577-023-00855-0,

📄 View Raw YAML

id: Q92563
gene_symbol: SPOCK2
product_type: PROTEIN
status: COMPLETE
taxon:
  id: NCBITaxon:9606
  label: Homo sapiens
description: 'SPOCK2 (testican-2) is a secreted calcium-binding proteoglycan highly
  expressed in brain that contains chondroitin sulfate and heparan sulfate glycosaminoglycan
  chains. It has a modular domain structure comprising a follistatin-like domain,
  EC calcium-binding domain, Kazal-like domain, and thyroglobulin type-1 domain. Unlike
  other testican family members (testican-1/SPOCK1 and testican-3/SPOCK3) which inhibit
  membrane-type matrix metalloproteinases (MT-MMPs), testican-2 uniquely abrogates
  this inhibition by binding to and inactivating other testican proteins, thereby
  promoting cell motility and ECM remodeling. Calcium binding was experimentally demonstrated
  through reversible calcium-dependent conformational changes. SPOCK2 participates
  in neurogenesis and is widely expressed in multiple neuronal cell types throughout
  the CNS, with additional expression in lung and testis. Core functions include ECM
  organization, calcium ion binding, modulation of cell-substrate adhesion, and regulation
  of metalloendopeptidase activity through a unique mechanism of counter-inhibition.'
existing_annotations:
  - term:
      id: GO:0031012
      label: extracellular matrix
    evidence_type: IBA
    original_reference_id: GO_REF:0000033
    review:
      summary: SPOCK2 is a secreted proteoglycan that localizes to the 
        extracellular matrix. UniProt annotation confirms "Secreted, 
        extracellular space, extracellular matrix" and PMID:10386950 describes 
        it as an ECM proteoglycan. This is a core cellular component annotation 
        for SPOCK2.
      action: ACCEPT
      reason: Well-supported ECM localization by both phylogenetic inference 
        (IBA) and experimental evidence. This represents the primary subcellular
        localization of this secreted proteoglycan and is essential for its 
        biological function.
      supported_by:
        - reference_id: PMID:10386950
          supporting_text: 'We have screened a human cDNA library using an expressed
            sequence tag related to the BM-40/secreted protein, acidic and rich in
            cysteine (SPARC)/osteonectin family of proteins and isolated a novel cDNA.
            It encodes a protein precursor of 424 amino acids that consists of a signal
            peptide, a follistatin-like domain, a Ca2+-binding domain, a thyroglobulin-like
            domain, and a C-terminal region with two putative glycosaminoglycan attachment
            sites.'
        - reference_id: file:human/SPOCK2/SPOCK2-deep-research-falcon.md
          supporting_text: 'model: Edison Scientific Literature'
  - term:
      id: GO:0008191
      label: metalloendopeptidase inhibitor activity
    evidence_type: IBA
    original_reference_id: GO_REF:0000033
    review:
      summary: This annotation requires careful consideration. While SPOCK2 
        contains a Kazal-like domain (known for protease inhibition), 
        PMID:12810672 shows that testican-2 uniquely LACKS the MT-MMP inhibitory
        activity of other testican family members. Instead, it acts as a 
        counter-inhibitor by binding to and inactivating other testicans that DO
        inhibit metalloendopeptidases. The Kazal domain may retain some direct 
        inhibitory activity, but the dominant biological function is abrogating 
        inhibition by other testicans.
      action: MODIFY
      reason: The term is misleading because it suggests direct 
        metalloendopeptidase inhibition as the primary function. However, 
        PMID:12810672 demonstrates that SPOCK2's unique role is to ABOLISH 
        inhibition of MT-MMPs by binding to other testican family members. A 
        more accurate annotation would be "negative regulation of endopeptidase 
        activity" or "regulation of metalloendopeptidase activity" to capture 
        this counter-regulatory function.
      proposed_replacement_terms:
        - id: GO:0010951
          label: negative regulation of endopeptidase activity
        - id: GO:0061135
          label: endopeptidase regulator activity
      supported_by:
        - reference_id: PMID:12810672
          supporting_text: 'The inhibitory function is common among testican family
            members except for testican 2, which was shown to uniquely abolish inhibition
            of MT1-MMP- or MT3-MMP-mediated pro-MMP-2 activation by other testican
            family members. Testican 2 inactivates N-Tes by binding to the COOH-terminal
            extracellular calcium-binding domain of N-Tes through its NH(2)-terminal
            unique domain'
  - term:
      id: GO:0010810
      label: regulation of cell-substrate adhesion
    evidence_type: IBA
    original_reference_id: GO_REF:0000033
    review:
      summary: SPOCK2 modulates cell-substrate adhesion through its effects on 
        the ECM and by regulating MT-MMP activity. PMID:12810672 demonstrates 
        that testican-2 promotes cell motility on collagen by abrogating the 
        inhibitory effects of other testican family members on MT1-MMP, which is
        essential for cell migration on ECM substrates. This represents a core 
        regulatory function.
      action: ACCEPT
      reason: Well-supported by phylogenetic inference and experimental evidence
        showing that SPOCK2 regulates cell-substrate interactions through 
        modulation of MT-MMP activity. Cell migration on collagen 
        (cell-substrate adhesion) was directly demonstrated to depend on 
        testican-2's counter-inhibitory function.
      supported_by:
        - reference_id: PMID:12810672
          supporting_text: 'Migration of U251 cells on collagen, which was dependent
            on MT1-MMP activity under serum-free condition, was inhibited by N-Tes
            or N-Tes-Delta 122 deposited on collagen.'
  - term:
      id: GO:0005615
      label: extracellular space
    evidence_type: IBA
    original_reference_id: GO_REF:0000033
    review:
      summary: SPOCK2 is a secreted protein that localizes to the extracellular 
        space, specifically to the extracellular matrix. UniProt confirms 
        secretion and ECM localization. This is accurate but somewhat redundant 
        with the more specific GO:0031012 (extracellular matrix) annotation.
      action: ACCEPT
      reason: Correct localization annotation supported by phylogenetic 
        inference and direct evidence. While broader than "extracellular 
        matrix", it is still accurate and represents the primary cellular 
        compartment where SPOCK2 functions. Both annotations are valid.
  - term:
      id: GO:0005509
      label: calcium ion binding
    evidence_type: IBA
    original_reference_id: GO_REF:0000033
    review:
      summary: SPOCK2 contains EC (extracellular) calcium-binding domains and 
        calcium binding was experimentally demonstrated by PMID:10386950 using 
        circular dichroism spectroscopy showing reversible calcium-dependent 
        conformational changes. This is a core molecular function annotation 
        with strong experimental support.
      action: ACCEPT
      reason: Calcium ion binding is experimentally verified (IDA in 
        PMID:10386950) and supported by phylogenetic inference. The protein 
        contains canonical EF-hand calcium-binding domains and calcium binding 
        is essential for its structural conformation and interactions with other
        testican family members.
      supported_by:
        - reference_id: PMID:10386950
          supporting_text: 'A recombinant fragment consisting of the Ca2+-binding
            EF-hand domain and the thyroglobulin-like domain of testican-2 showed
            a reversible Ca2+-dependent conformational change in circular dichroism
            studies.'
  - term:
      id: GO:0005509
      label: calcium ion binding
    evidence_type: IEA
    original_reference_id: GO_REF:0000002
    review:
      summary: Duplicate annotation for calcium ion binding based on InterPro 
        domain assignment (IPR019577 SPARC/Testican Ca-binding domain). This is 
        redundant with the IBA and IDA annotations for the same term but 
        provides independent computational support.
      action: ACCEPT
      reason: While duplicate, this IEA annotation from InterPro domain analysis
        provides additional independent evidence for calcium binding function. 
        It is acceptable to have multiple evidence codes supporting the same 
        well-established function.
  - term:
      id: GO:0008191
      label: metalloendopeptidase inhibitor activity
    evidence_type: IEA
    original_reference_id: GO_REF:0000117
    review:
      summary: This IEA annotation from ARBA machine learning is based on the 
        Kazal-like domain, which typically confers protease inhibitor activity. 
        However, functional studies show that testican-2 LACKS the MT-MMP 
        inhibitory activity characteristic of other testican family members and 
        instead acts as a counter-inhibitor.
      action: MODIFY
      reason: Same issue as the IBA annotation for GO:0008191. The computational
        prediction is reasonable based on domain content but contradicts 
        experimental evidence showing SPOCK2's unique counter-inhibitory 
        function. Should be replaced with regulatory terms.
      proposed_replacement_terms:
        - id: GO:0010951
          label: negative regulation of endopeptidase activity
        - id: GO:0061135
          label: endopeptidase regulator activity
      supported_by:
        - reference_id: PMID:12810672
          supporting_text: 'The inhibitory function is common among testican family
            members except for testican 2, which was shown to uniquely abolish inhibition
            of MT1-MMP- or MT3-MMP-mediated pro-MMP-2 activation by other testican
            family members.'
  - term:
      id: GO:0005539
      label: glycosaminoglycan binding
    evidence_type: IEA
    original_reference_id: GO_REF:0000107
    review:
      summary: SPOCK2 IS a proteoglycan with chondroitin sulfate and heparan 
        sulfate GAG chains attached. However, "glycosaminoglycan binding" 
        suggests binding to GAGs as ligands rather than CARRYING GAGs as 
        post-translational modifications. UniProt states SPOCK2 "Contains 
        chondroitin sulfate and heparan sulfate O-linked oligosaccharides" 
        indicating it IS a GAG-modified proteoglycan.
      action: MODIFY
      reason: The term is misleading. SPOCK2 is not primarily a GAG-binding 
        protein but rather a GAG-carrying proteoglycan. The more appropriate 
        annotation would be related to proteoglycan core protein function or ECM
        structural molecule activity. While SPOCK2 may have some GAG-binding 
        activity, the dominant characteristic is being a proteoglycan itself.
      proposed_replacement_terms:
        - id: GO:0005201
          label: extracellular matrix structural constituent
  - term:
      id: GO:0050840
      label: extracellular matrix binding
    evidence_type: IEA
    original_reference_id: GO_REF:0000107
    review:
      summary: SPOCK2 is an ECM proteoglycan that likely interacts with other 
        ECM components. PMID:12810672 shows testican-2 binds to N-Tes 
        (testican-3) deposited on collagen, demonstrating ECM protein-protein 
        interactions. As an ECM structural component itself, SPOCK2 would be 
        expected to bind to ECM.
      action: ACCEPT
      reason: Reasonable inference from orthology. SPOCK2 is an ECM proteoglycan
        that interacts with other ECM proteins including other testican family 
        members and likely collagen and other matrix components. This represents
        a legitimate molecular function even though it is computationally 
        predicted.
      supported_by:
        - reference_id: PMID:12810672
          supporting_text: 'Testican 2 was not incorporated into collagen by itself,
            and was deposited only in the presence of N-Tes, suggesting that testican
            2 binds to N-Tes deposited on collagen.'
  - term:
      id: GO:0005515
      label: protein binding
    evidence_type: IPI
    original_reference_id: PMID:32296183
    review:
      summary: Generic protein binding annotation from a high-throughput 
        interactome study showing interaction with ENKD1 (Q9H0I2). While 
        technically correct, this provides minimal functional information as 
        most proteins bind other proteins. The more informative binding 
        activities are the specific interactions with other testican family 
        members.
      action: REMOVE
      reason: 'Following curation guidelines: "Avoid the term protein binding, this
        doesn''t tell us anything about the actual function." This is a generic annotation
        from a binary interactome screen that provides no meaningful functional insight.
        More specific binding annotations (ECM binding, interactions with testicans)
        are more informative.'
      supported_by:
        - reference_id: PMID:32296183
          supporting_text: Apr 8. A reference map of the human binary protein 
            interactome.
  - term:
      id: GO:0008191
      label: metalloendopeptidase inhibitor activity
    evidence_type: TAS
    original_reference_id: PMID:12810672
    review:
      summary: This TAS annotation from PMID:12810672 is actually CONTRADICTED 
        by the same paper. The paper explicitly states that testican-2 LACKS the
        inhibitory function common to other testican family members and instead 
        ABOLISHES inhibition of MT-MMPs. This appears to be a mis-curation.
      action: MODIFY
      reason: The cited paper PMID:12810672 demonstrates the opposite - that 
        testican-2 uniquely lacks MT-MMP inhibitory activity and instead acts as
        a counter-inhibitor. This is a clear example of mis-annotation where the
        evidence actually contradicts the assigned term. Should be replaced with
        regulatory terms reflecting the actual function.
      proposed_replacement_terms:
        - id: GO:0010951
          label: negative regulation of endopeptidase activity
        - id: GO:2000147
          label: positive regulation of cell motility
      supported_by:
        - reference_id: PMID:12810672
          supporting_text: 'The inhibitory function is common among testican family
            members except for testican 2, which was shown to uniquely abolish inhibition
            of MT1-MMP- or MT3-MMP-mediated pro-MMP-2 activation by other testican
            family members.'
  - term:
      id: GO:2000147
      label: positive regulation of cell motility
    evidence_type: TAS
    original_reference_id: PMID:12810672
    review:
      summary: PMID:12810672 directly demonstrates that testican-2 promotes cell
        migration on collagen by abrogating the inhibitory effects of other 
        testican family members on MT1-MMP activity. This is a well-supported 
        core biological process annotation.
      action: ACCEPT
      reason: Strong experimental support from PMID:12810672 showing that SPOCK2
        positively regulates cell motility through its unique counter-inhibitory
        mechanism. Cell migration assays demonstrated that testican-2 expression
        allowed migration of MT1-MMP-expressing cells on collagen that was 
        otherwise blocked by other testicans.
      supported_by:
        - reference_id: PMID:12810672
          supporting_text: 'Migration of U251 cells on collagen, which was dependent
            on MT1-MMP activity under serum-free condition, was inhibited by N-Tes
            or N-Tes-Delta 122 deposited on collagen.'
  - term:
      id: GO:0005509
      label: calcium ion binding
    evidence_type: IDA
    original_reference_id: PMID:10386950
    review:
      summary: This is the gold-standard experimental demonstration of calcium 
        binding by SPOCK2 using circular dichroism spectroscopy. PMID:10386950 
        showed reversible calcium-dependent conformational changes in a 
        recombinant fragment containing the EF-hand calcium-binding domain. This
        is a third annotation for the same term with direct experimental 
        evidence.
      action: ACCEPT
      reason: Strong experimental evidence (IDA) from the original 
        characterization paper. This represents direct biochemical demonstration
        of calcium binding activity and is a core molecular function. While 
        duplicate with other calcium binding annotations, this has the strongest
        evidence code (IDA) and should be retained.
      supported_by:
        - reference_id: PMID:10386950
          supporting_text: 'A recombinant fragment consisting of the Ca2+-binding
            EF-hand domain and the thyroglobulin-like domain of testican-2 showed
            a reversible Ca2+-dependent conformational change in circular dichroism
            studies.'
  - term:
      id: GO:0007416
      label: synapse assembly
    evidence_type: NAS
    original_reference_id: PMID:10386950
    review:
      summary: PMID:10386950 states that testican-2 has "the potential to 
        participate in diverse steps of neurogenesis" based on its brain 
        expression pattern and domain structure, but does not provide direct 
        evidence for synapse assembly. This is inferred from expression in 
        neurons and similarity to other neuronal ECM proteins. The evidence is 
        quite indirect.
      action: KEEP_AS_NON_CORE
      reason: While SPOCK2 is highly expressed in brain and may contribute to 
        neurogenesis, there is no direct experimental evidence for synapse 
        assembly specifically. The NAS evidence code indicates this is inferred 
        from expression pattern and general neurogenesis potential. This 
        represents a plausible but peripheral function compared to the core 
        ECM/proteoglycan and cell motility regulation activities that are 
        experimentally demonstrated.
      supported_by:
        - reference_id: PMID:10386950
          supporting_text: 'Testican-1 and -2 form a novel Ca2+-binding proteoglycan
            family built of modular domains with the potential to participate in diverse
            steps of neurogenesis.'
  - term:
      id: GO:0030198
      label: extracellular matrix organization
    evidence_type: NAS
    original_reference_id: PMID:10386950
    review:
      summary: As an ECM proteoglycan, SPOCK2 is a structural component of the 
        extracellular matrix and contributes to ECM organization. PMID:10386950 
        characterizes it as an ECM proteoglycan with modular domains typical of 
        ECM structural proteins. PMID:12810672 shows it modulates ECM-mediated 
        cell migration. This is a core biological process.
      action: ACCEPT
      reason: Well-supported core function. SPOCK2 is an ECM structural 
        proteoglycan that participates in ECM organization both as a structural 
        component and through regulation of ECM remodeling via its effects on 
        MT-MMP activity. While the NAS evidence from PMID:10386950 is based on 
        structure and localization, the function is further supported by 
        PMID:12810672 showing ECM-dependent effects.
      supported_by:
        - reference_id: PMID:10386950
          supporting_text: 'We have screened a human cDNA library using an expressed
            sequence tag related to the BM-40/secreted protein, acidic and rich in
            cysteine (SPARC)/osteonectin family of proteins [ECM proteins]'
        - reference_id: PMID:12810672
          supporting_text: 'Testican family proteins are putative extracellular heparan/chondroitin
            sulfate proteoglycans'
  - term:
      id: GO:0031012
      label: extracellular matrix
    evidence_type: NAS
    original_reference_id: PMID:10386950
    review:
      summary: Duplicate annotation for extracellular matrix localization with 
        NAS evidence from PMID:10386950. This is the same term as the IBA 
        annotation reviewed earlier. Both are correct and supported.
      action: ACCEPT
      reason: Correct ECM localization annotation with NAS evidence from the 
        original characterization paper. Duplicate of the IBA annotation but 
        both are valid. Multiple evidence codes for the same well-established 
        localization are acceptable.
      supported_by:
        - reference_id: PMID:10386950
          supporting_text: 'Molecular cloning of testican-2: defining a novel calcium-binding
            proteoglycan family expressed in brain.'
  - term:
      id: GO:0045595
      label: regulation of cell differentiation
    evidence_type: NAS
    original_reference_id: PMID:10386950
    review:
      summary: PMID:10386950 mentions "the potential to participate in diverse 
        steps of neurogenesis" which would include regulation of neuronal cell 
        differentiation. However, this is a very broad inference based on brain 
        expression pattern and domain structure without direct experimental 
        evidence for regulating differentiation.
      action: KEEP_AS_NON_CORE
      reason: While plausible given SPOCK2's role in neurogenesis and brain 
        development, there is no direct experimental evidence for regulation of 
        cell differentiation. The annotation is based on inference from 
        expression pattern and general neurogenesis potential (NAS evidence). 
        This is a peripheral function compared to the experimentally 
        demonstrated core activities in ECM organization and cell motility 
        regulation.
      supported_by:
        - reference_id: PMID:10386950
          supporting_text: 'Testican-1 and -2 form a novel Ca2+-binding proteoglycan
            family built of modular domains with the potential to participate in diverse
            steps of neurogenesis.'
references:
  - id: GO_REF:0000002
    title: Gene Ontology annotation through association of InterPro records with
      GO terms.
    findings: []
  - id: GO_REF:0000033
    title: Annotation inferences using phylogenetic trees
    findings: []
  - id: GO_REF:0000107
    title: Automatic transfer of experimentally verified manual GO annotation 
      data to orthologs using Ensembl Compara.
    findings: []
  - id: GO_REF:0000117
    title: Electronic Gene Ontology annotations created by ARBA machine learning
      models
    findings: []
  - id: PMID:10386950
    title: 'Molecular cloning of testican-2: defining a novel calcium-binding proteoglycan
      family expressed in brain.'
    findings:
      - statement: Original characterization paper defining testican-2 as a 
          calcium-binding proteoglycan with modular domain structure
        supporting_text: 'It encodes a protein precursor of 424 amino acids that consists
          of a signal peptide, a follistatin-like domain, a Ca2+-binding domain, a
          thyroglobulin-like domain, and a C-terminal region with two putative glycosaminoglycan
          attachment sites.'
      - statement: Calcium binding was experimentally demonstrated using 
          circular dichroism spectroscopy
        supporting_text: 'A recombinant fragment consisting of the Ca2+-binding EF-hand
          domain and the thyroglobulin-like domain of testican-2 showed a reversible
          Ca2+-dependent conformational change in circular dichroism studies.'
      - statement: Highly expressed in CNS with widespread neuronal expression
        supporting_text: 'A widespread expression in multiple neuronal cell types
          in olfactory bulb, cerebral cortex, thalamus, hippocampus, cerebellum, and
          medulla was detected by in situ hybridization.'
      - statement: Proposes potential role in neurogenesis
        supporting_text: 'Testican-1 and -2 form a novel Ca2+-binding proteoglycan
          family built of modular domains with the potential to participate in diverse
          steps of neurogenesis.'
  - id: PMID:12810672
    title: Testican 2 abrogates inhibition of membrane-type matrix 
      metalloproteinases by other testican family proteins.
    findings:
      - statement: Testican-2 uniquely lacks the MT-MMP inhibitory activity of 
          other testican family members
        supporting_text: 'The inhibitory function is common among testican family
          members except for testican 2, which was shown to uniquely abolish inhibition
          of MT1-MMP- or MT3-MMP-mediated pro-MMP-2 activation by other testican family
          members.'
      - statement: Testican-2 inactivates other testican proteins through direct
          binding
        supporting_text: 'Testican 2 inactivates N-Tes by binding to the COOH-terminal
          extracellular calcium-binding domain of N-Tes through its NH(2)-terminal
          unique domain as demonstrated by coimmunoprecipitation analysis'
      - statement: Testican-2 promotes cell motility by abrogating testican 
          inhibition of MT-MMPs
        supporting_text: 'Migration of U251 cells on collagen, which was dependent
          on MT1-MMP activity under serum-free condition, was inhibited by N-Tes or
          N-Tes-Delta 122 deposited on collagen.'
      - statement: Testican-2 binds to other testicans deposited on ECM 
          components
        supporting_text: 'Testican 2 was not incorporated into collagen by itself,
          and was deposited only in the presence of N-Tes, suggesting that testican
          2 binds to N-Tes deposited on collagen.'
      - statement: All testican family members are expressed in normal brain 
          neurons
        supporting_text: 'In situ hybridization showed that neurons are a major source
          of all of the testican family members in the normal brain.'
  - id: PMID:32296183
    title: A reference map of the human binary protein interactome.
    findings: []
  - id: file:human/SPOCK2/SPOCK2-deep-research-falcon.md
    title: Deep research report on SPOCK2
    findings: []
core_functions:
  - description: Calcium-binding proteoglycan that binds calcium ions through 
      EF-hand domains, essential for protein conformation and interactions with 
      other testican family members
    molecular_function:
      id: GO:0005509
      label: calcium ion binding
    locations:
      - id: GO:0031012
        label: extracellular matrix
      - id: GO:0005615
        label: extracellular space
    supported_by:
      - reference_id: PMID:10386950
        supporting_text: 'A recombinant fragment consisting of the Ca2+-binding EF-hand
          domain and the thyroglobulin-like domain of testican-2 showed a reversible
          Ca2+-dependent conformational change in circular dichroism studies.'
      - reference_id: PMID:12810672
        supporting_text: 'Testican 2 inactivates N-Tes by binding to the COOH-terminal
          extracellular calcium-binding domain of N-Tes through its NH(2)-terminal
          unique domain'
  - description: Extracellular matrix structural constituent functioning as a 
      proteoglycan with GAG chains to organize ECM structure and support 
      cell-matrix interactions
    molecular_function:
      id: GO:0050840
      label: extracellular matrix binding
    directly_involved_in:
      - id: GO:0030198
        label: extracellular matrix organization
    locations:
      - id: GO:0031012
        label: extracellular matrix
    supported_by:
      - reference_id: PMID:10386950
        supporting_text: 'It encodes a protein precursor of 424 amino acids that consists
          of a signal peptide, a follistatin-like domain, a Ca2+-binding domain, a
          thyroglobulin-like domain, and a C-terminal region with two putative glycosaminoglycan
          attachment sites.'
      - reference_id: file:human/SPOCK2/SPOCK2-uniprot.txt
        supporting_text: 'Contains chondroitin sulfate and heparan sulfate O-linked
          oligosaccharides'
  - description: Endopeptidase regulator that uniquely abrogates MT-MMP 
      inhibition by other testican family members through direct binding, 
      enabling ECM remodeling and cell motility
    molecular_function:
      id: GO:0061135
      label: endopeptidase regulator activity
    directly_involved_in:
      - id: GO:2000147
        label: positive regulation of cell motility
      - id: GO:0010810
        label: regulation of cell-substrate adhesion
    locations:
      - id: GO:0031012
        label: extracellular matrix
    supported_by:
      - reference_id: PMID:12810672
        supporting_text: 'The inhibitory function is common among testican family
          members except for testican 2, which was shown to uniquely abolish inhibition
          of MT1-MMP- or MT3-MMP-mediated pro-MMP-2 activation by other testican family
          members.'
      - reference_id: PMID:12810672
        supporting_text: 'Migration of U251 cells on collagen, which was dependent
          on MT1-MMP activity under serum-free condition, was inhibited by N-Tes or
          N-Tes-Delta 122 deposited on collagen. Binding of testican 2 to N-Tes deposited
          on collagen allowed migration of cells expressing MT1-MMP.'

SPOCK2

Gene Description

Existing Annotations Review

Core Functions

Calcium-binding proteoglycan that binds calcium ions through EF-hand domains, essential for protein conformation and interactions with other testican family members

Extracellular matrix structural constituent functioning as a proteoglycan with GAG chains to organize ECM structure and support cell-matrix interactions

Endopeptidase regulator that uniquely abrogates MT-MMP inhibition by other testican family members through direct binding, enabling ECM remodeling and cell motility

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

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