SCAMP5 (Secretory carrier-associated membrane protein 5) is a brain-enriched, tetraspanning membrane protein of the SCAMP family that functions as a key organizer of vesicular trafficking pathways. SCAMP5 localizes predominantly to synaptic vesicles, the trans-Golgi network (TGN), and recycling endosomes. Its N-terminal region directly binds the mu4 subunit of the AP-4 adaptor complex, enabling recruitment of AP-4 to the TGN and facilitating export of ATG9A to axons and presynaptic terminals, thereby enabling presynaptic autophagy and synaptic vesicle protein turnover. SCAMP5 also cooperates with SNARE machinery by interacting with synaptotagmins (SYT1, SYT2) via its C-terminal tail, promoting calcium-triggered exocytosis of signal peptide-containing cytokines such as CCL5. Additionally, SCAMP5 interacts with the organellar Na+/K+/H+ exchanger NHE7 (SLC9A7) and participates in shuttling NHE7 between recycling vesicles and the TGN. Disease-associated variants in SCAMP5 are linked to neurodevelopmental disorders with seizures, and increased SCAMP5 expression under ER stress contributes to polyglutamine aggregate accumulation via endocytosis inhibition.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0006887 exocytosis | IBA GO_REF:0000033 | ACCEPT | Summary: SCAMP5 is involved in calcium-regulated exocytosis as demonstrated by functional studies showing it promotes calcium-triggered cytokine secretion (PMID:19234194). The IBA annotation is consistent with experimental evidence from multiple publications. Reason: The IBA annotation is well-supported by experimental evidence from Han et al. (2009) showing SCAMP5 facilitates calcium-triggered exocytosis of cytokines in cooperation with SNARE machinery. This represents a core function of SCAMP5. Supporting Evidence: PMID:19234194 hSCAMP5, in cooperation with the SNARE machinery, is involved in calcium-regulated exocytosis of signal peptide-containing cytokines file:human/SCAMP5/SCAMP5-deep-research-falcon.md model: Edison Scientific Literature |
| GO:0032588 trans-Golgi network membrane | IBA GO_REF:0000033 | ACCEPT | Summary: SCAMP5 localizes primarily to the trans-Golgi network membrane, confirmed by multiple studies using immunofluorescence microscopy and subcellular fractionation (PMID:15840657, PMID:19234194). Reason: The IBA annotation is strongly supported by experimental IDA evidence. Lin et al. (2005) showed SCAMP5 accumulates at the TGN as part of complexes with NHE7, and Han et al. (2009) confirmed Golgi-associated localization. Supporting Evidence: PMID:15840657 The majority of the NHE7-SCAMP complexes accumulated at the TGN PMID:19234194 hSCAMP5 is mainly localized in the Golgi-associated compartments |
| GO:0055038 recycling endosome membrane | IBA GO_REF:0000033 | ACCEPT | Summary: SCAMP5 is present on recycling endosome membranes, where it participates in trafficking of cargo proteins like NHE7 between recycling vesicles and the TGN (PMID:15840657). Reason: The IBA annotation is supported by experimental evidence from Lin et al. (2005) demonstrating that SCAMP proteins including SCAMP5 reside in recycling vesicles as part of trafficking complexes. Supporting Evidence: PMID:15840657 a minor fraction also resided in recycling vesicles |
| GO:0000139 Golgi membrane | IEA GO_REF:0000044 | ACCEPT | Summary: SCAMP5 is located on the Golgi membrane, which is consistent with its primary localization at the trans-Golgi network. The IEA annotation based on UniProt subcellular location is supported by experimental evidence. Reason: The IEA annotation is correct and consistent with the more specific IDA annotations for TGN membrane localization. Multiple studies confirm Golgi-associated localization of SCAMP5. Supporting Evidence: PMID:19234194 hSCAMP5 is mainly localized in the Golgi-associated compartments |
| GO:0005794 Golgi apparatus | IEA GO_REF:0000044 | ACCEPT | Summary: SCAMP5 is located in the Golgi apparatus as a multi-pass membrane protein. This IEA annotation is a valid broader localization consistent with the more specific TGN membrane annotations. Reason: The annotation is correct as a parent term of the more specific TGN membrane localization. Experimental evidence confirms Golgi apparatus localization. Supporting Evidence: PMID:19234194 hSCAMP5 is mainly localized in the Golgi-associated compartments |
| GO:0005886 plasma membrane | IEA GO_REF:0000044 | ACCEPT | Summary: SCAMP5 translocates to the plasma membrane upon calcium-triggered exocytosis. This is a dynamic localization rather than steady-state, representing its functional role in exocytosis. Reason: The annotation is supported by experimental evidence showing SCAMP5 translocates from Golgi to plasma membrane during calcium-triggered exocytosis (PMID:19234194). Supporting Evidence: PMID:19234194 calcium ionophore ionomycin can trigger a rapid translocation of hSCAMP5 from Golgi apparatus to plasma membrane along the classical exocytosis pathway |
| GO:0006887 exocytosis | IEA GO_REF:0000043 | ACCEPT | Summary: This IEA annotation for exocytosis is based on UniProt keyword mapping and is redundant with the IBA annotation. Both are correct. Reason: The annotation is correct and consistent with experimental evidence for SCAMP5 function in exocytosis. Duplicate GO IDs with different evidence codes are acceptable. Supporting Evidence: PMID:19234194 hSCAMP5, in cooperation with the SNARE machinery, is involved in calcium-regulated exocytosis |
| GO:0015031 protein transport | IEA GO_REF:0000120 | ACCEPT | Summary: SCAMP5 is involved in protein transport as part of its core function in vesicular trafficking. This includes transport of NHE7 between TGN and recycling vesicles, as well as ATG9A trafficking to presynaptic terminals. Reason: The annotation is a valid broader term for SCAMP5 function. The protein participates in transport of multiple cargo proteins including NHE7 and ATG9A through the secretory/endosomal pathway. Supporting Evidence: PMID:15840657 SCAMPs participate in the shuttling of NHE7 between recycling vesicles and the TGN |
| GO:0016020 membrane | IEA GO_REF:0000002 | ACCEPT | Summary: SCAMP5 is a multi-pass transmembrane protein with four transmembrane helices. This is the broadest valid membrane localization term. Reason: The annotation is correct but very general. SCAMP5 has four predicted transmembrane domains and localizes to multiple membrane compartments. Supporting Evidence: PMID:19234194 Secretory carrier membrane proteins (SCAMPs) are widely distributed integral membrane molecules |
| GO:0030672 synaptic vesicle membrane | IEA GO_REF:0000044 | ACCEPT | Summary: SCAMP5 is highly enriched in synaptic vesicles, particularly in neurons where it plays key roles in synaptic vesicle cycling and presynaptic autophagy. The deep research confirms synaptic vesicle enrichment. Reason: The annotation is well-supported by recent literature demonstrating SCAMP5 localization to synaptic vesicles and its function in synaptic vesicle endocytosis and presynaptic autophagy. Supporting Evidence: PMID:19234194 In this study, we report the functional characterization of human SCAMP5 (hSCAMP5), a novel SCAMP protein that is widely expressed by a variety of neuronal and nonneuronal tissues and cells |
| GO:0031410 cytoplasmic vesicle | IEA GO_REF:0000043 | ACCEPT | Summary: SCAMP5 localizes to cytoplasmic vesicles including secretory vesicles, recycling endosomes, and synaptic vesicles. This is a valid but general localization annotation. Reason: The annotation is correct as a broad localization term. SCAMP5 is found on multiple types of cytoplasmic vesicles as part of its trafficking function. Supporting Evidence: PMID:15840657 a minor fraction also resided in recycling vesicles |
| GO:0055038 recycling endosome membrane | IEA GO_REF:0000044 | ACCEPT | Summary: This IEA annotation for recycling endosome membrane is redundant with the IBA annotation but remains valid based on experimental evidence. Reason: The annotation is correct and supported by experimental evidence from Lin et al. (2005). Duplicate annotations with different evidence codes are acceptable. Supporting Evidence: PMID:15840657 a minor fraction also resided in recycling vesicles |
| GO:0005515 protein binding | IPI PMID:19234194 Human SCAMP5, a novel secretory carrier membrane protein, fa... | MODIFY | Summary: This protein binding annotation refers to the interaction of SCAMP5 with synaptotagmins (SYT1, SYT2) via its C-terminal tail. While the interaction is valid, the term is too general. Reason: The protein binding term is uninformative. SCAMP5 interacts specifically with synaptotagmins as calcium sensors in the context of SNARE-mediated exocytosis. A more specific MF term would better capture this function. Proposed replacements: syntaxin-1 binding Supporting Evidence: PMID:19234194 hSCAMP5 can directly interact with the calcium sensor synaptotagmins via the cytosolic C-terminal tail of hSCAMP5 |
| GO:0005515 protein binding | IPI PMID:32296183 A reference map of the human binary protein interactome. | MARK AS OVER ANNOTATED | Summary: This protein binding annotation is from the HuRI high-throughput interactome study. While valid, protein binding is too general to be informative for the molecular function of SCAMP5. Reason: The HuRI study (PMID:32296183) detected many protein-protein interactions in a high-throughput screen. While technically correct, protein binding annotations from such studies are overly general and do not inform about the specific molecular function of SCAMP5. Supporting Evidence: PMID:32296183 HuRI, a systematically generated human protein interactome map with more than 50,000 PPIs |
| GO:0044877 protein-containing complex binding | IDA PMID:19234194 Human SCAMP5, a novel secretory carrier membrane protein, fa... | ACCEPT | Summary: SCAMP5 interacts with SNARE machinery components as protein complexes during calcium-triggered exocytosis. This annotation captures the interaction with SNARE complexes. Reason: The annotation is supported by evidence that SCAMP5 codistributes and complexes with SNARE molecules during translocation from Golgi to plasma membrane. This represents SCAMP5 binding to protein complexes. Supporting Evidence: PMID:19234194 hSCAMP5 can codistribute and complex with local soluble N-ethylmaleimide sensitive factor attachment protein receptors (SNAREs) molecules |
| GO:0000139 Golgi membrane | IDA PMID:19234194 Human SCAMP5, a novel secretory carrier membrane protein, fa... | ACCEPT | Summary: SCAMP5 localization to Golgi membrane was demonstrated by immunofluorescence confocal microscopy and subcellular fractionation in Han et al. (2009). Reason: The annotation is well-supported by experimental evidence showing SCAMP5 is mainly localized in Golgi-associated compartments. Supporting Evidence: PMID:19234194 By using subcellular fractionation, immunofluorescence confocal microscopy, and membrane vesicle immunoisolation methods, we find that hSCAMP5 is mainly localized in the Golgi-associated compartments |
| GO:0001819 positive regulation of cytokine production | IDA PMID:19234194 Human SCAMP5, a novel secretory carrier membrane protein, fa... | ACCEPT | Summary: SCAMP5 promotes calcium-regulated secretion of signal peptide-containing cytokines such as CCL5/RANTES. This was demonstrated in multiple cell types including epithelial cancer cells, monocytes, and macrophages. Reason: The annotation is directly supported by experimental evidence from Han et al. (2009) showing SCAMP5 promotes cytokine secretion. This represents a downstream consequence of its exocytosis function. Supporting Evidence: PMID:19234194 hSCAMP5 can promote the calcium-regulated signal peptide-containing cytokine (CCL5 but not IL-1beta) secretion in human epithelial cancer cells, human monocytes, and mouse macrophages |
| GO:0005515 protein binding | IPI PMID:15840657 Secretory carrier membrane proteins interact and regulate tr... | MODIFY | Summary: This protein binding annotation refers to the interaction between SCAMP5 and NHE7/SLC9A7, where SCAMP5 participates in trafficking NHE7 between the TGN and recycling vesicles. Reason: While the interaction with NHE7 is valid and functionally important, the generic protein binding term does not capture the specific nature of this trafficking relationship. A more specific term would be informative. Proposed replacements: symporter activity Supporting Evidence: PMID:15840657 SCAMP1 and SCAMP5, also associated with NHE7 |
| GO:0005515 protein binding | IPI PMID:19234194 Human SCAMP5, a novel secretory carrier membrane protein, fa... | MARK AS OVER ANNOTATED | Summary: This protein binding annotation is for interaction with SYT1 and potentially other proteins. As with other protein binding annotations, this is too general to be informative. Reason: Protein binding is an uninformative molecular function term. The relevant functional information (interaction with synaptotagmins for exocytosis) is better captured by process annotations. Supporting Evidence: PMID:19234194 hSCAMP5 can directly interact with the calcium sensor synaptotagmins |
| GO:0005886 plasma membrane | IDA PMID:19234194 Human SCAMP5, a novel secretory carrier membrane protein, fa... | ACCEPT | Summary: SCAMP5 translocates to the plasma membrane upon calcium-triggered exocytosis, as demonstrated by immunofluorescence microscopy. Reason: The annotation is supported by direct experimental evidence showing ionomycin triggers rapid translocation of SCAMP5 from Golgi to plasma membrane during exocytosis. Supporting Evidence: PMID:19234194 the calcium ionophore ionomycin can trigger a rapid translocation of hSCAMP5 from Golgi apparatus to plasma membrane |
| GO:0016020 membrane | IDA PMID:19234194 Human SCAMP5, a novel secretory carrier membrane protein, fa... | ACCEPT | Summary: SCAMP5 is an integral membrane protein. This is a valid but very general localization annotation. Reason: The annotation is correct but very general. More specific membrane localization annotations (TGN, Golgi, plasma membrane) are preferred. Supporting Evidence: PMID:19234194 Secretory carrier membrane proteins (SCAMPs) are widely distributed integral membrane molecules |
| GO:0032588 trans-Golgi network membrane | IDA PMID:15840657 Secretory carrier membrane proteins interact and regulate tr... | ACCEPT | Summary: SCAMP5 localizes to the trans-Golgi network membrane where it forms complexes with NHE7 and participates in cargo trafficking. Reason: The annotation is well-supported by experimental evidence from Lin et al. (2005) showing SCAMP5-NHE7 complexes accumulate at the TGN. Supporting Evidence: PMID:15840657 The majority of the NHE7-SCAMP complexes accumulated at the TGN |
| GO:0034976 response to endoplasmic reticulum stress | IDA PMID:19240033 SCAMP5 links endoplasmic reticulum stress to the accumulatio... | KEEP AS NON CORE | Summary: SCAMP5 expression is induced by ER stress, and elevated SCAMP5 levels contribute to polyglutamine aggregate accumulation via endocytosis inhibition. This represents a pathological response. Reason: While SCAMP5 is induced by ER stress and contributes to disease pathology in Huntington's disease models, this is not a core physiological function but rather a pathological response. The annotation is valid but should be marked as non-core. Supporting Evidence: PMID:19240033 Expression of SCAMP5 is markedly increased in the striatum of Huntington disease patients and is induced in cultured striatal neurons by endoplasmic reticulum (ER) stress or by mtHTT |
| GO:0045806 negative regulation of endocytosis | IDA PMID:19240033 SCAMP5 links endoplasmic reticulum stress to the accumulatio... | KEEP AS NON CORE | Summary: Increased SCAMP5 expression impairs endocytosis, which in turn enhances mutant huntingtin aggregation. This is observed in the context of ER stress and Huntington's disease pathology. Reason: The negative regulation of endocytosis by elevated SCAMP5 is a pathological effect observed under ER stress conditions, not a core physiological function. The annotation is valid but represents a disease-related pleiotropic effect. Supporting Evidence: PMID:19240033 The increase of SCAMP5 impairs endocytosis, which in turn enhances mtHTT aggregation |
| GO:0045956 positive regulation of calcium ion-dependent exocytosis | IDA PMID:19234194 Human SCAMP5, a novel secretory carrier membrane protein, fa... | ACCEPT | Summary: SCAMP5 positively regulates calcium-dependent exocytosis by interacting with synaptotagmins and SNARE machinery to promote cytokine secretion. Reason: This is a core function of SCAMP5 well-supported by experimental evidence from Han et al. (2009). SCAMP5 facilitates calcium-triggered exocytosis in cooperation with SNARE machinery. Supporting Evidence: PMID:19234194 hSCAMP5, in cooperation with the SNARE machinery, is involved in calcium-regulated exocytosis of signal peptide-containing cytokines |
| GO:0055038 recycling endosome membrane | IDA PMID:15840657 Secretory carrier membrane proteins interact and regulate tr... | ACCEPT | Summary: SCAMP5 localizes to recycling endosome membranes where it participates in trafficking cargo proteins like NHE7. Reason: The annotation is supported by experimental evidence from Lin et al. (2005) showing a fraction of SCAMP-NHE7 complexes reside in recycling vesicles. Supporting Evidence: PMID:15840657 a minor fraction also resided in recycling vesicles |
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Download this section (compressed HTML)Q: What is the precise binding interface between SCAMP5 N-terminus and AP-4 mu4 subunit?
Q: How does SCAMP5 coordinate its dual roles in exocytosis and autophagy pathways?
Q: Do disease-associated SCAMP5 variants (R91W, G180W) affect ATG9A trafficking specifically?
Experiment: Cryo-EM structure of SCAMP5-AP4 complex to define molecular interaction interface
Hypothesis: The N-terminal cytoplasmic region of SCAMP5 directly contacts AP4M1 through specific binding motifs
Experiment: Live-cell imaging of SCAMP5 dynamics during synaptic vesicle cycling in neurons
Hypothesis: SCAMP5 cycles between synaptic vesicles and the TGN during neuronal activity
Experiment: Functional rescue experiments with SCAMP5 variants in patient-derived neurons
Hypothesis: Disease-associated SCAMP5 variants (R91W, G180W) impair presynaptic autophagy
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