BLOC1S1, also called BLOS1 or GCN5L1, is a small shared subunit of the BLOC-1 and BORC trafficking complexes. In BLOC-1 it helps maintain the assembly that organizes endosomal cargo delivery and lysosome-related organelle biogenesis. In BORC it supports complex stability and ARL8-dependent outward positioning of lysosomes from the cytoplasmic surface of the lysosomal membrane. BLOC1S1 also has cytosolic and mitochondrial pools and promotes protein acetylation associated with respiratory regulation; cellular acetylation experiments have not yet resolved whether it provides an intrinsic acetyl-transfer catalytic site or supports other components of the acetylation machinery.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0005515 protein binding | IPI PMID:15102850 Identification of snapin and three novel proteins (BLOS1, BL... | KEEP AS NON CORE | Summary: BLOS1 association with SNAPIN is compatible with BLOC-1 assembly. Reason: PMID:15102850 identifies endogenous BLOS1 in the same BLOC-1 complex as the listed partner and reports a binary-interaction network. The canonical cache is abstract-only, so the individual pair experiment has not been independently reconstructed. Retain the curator-supported physical association as non-core; the assembled trafficking complex is more informative than generic binding. This does not assert that every co-complex pair is a direct binary contact. |
| GO:0005515 protein binding | IPI PMID:15102850 Identification of snapin and three novel proteins (BLOS1, BL... | KEEP AS NON CORE | Summary: BLOS1 association with BLOC1S2/BLOS2 is compatible with BLOC-1 assembly. Reason: PMID:15102850 identifies endogenous BLOS1 in the same BLOC-1 complex as the listed partner and reports a binary-interaction network. The canonical cache is abstract-only, so the individual pair experiment has not been independently reconstructed. Retain the curator-supported physical association as non-core; the assembled trafficking complex is more informative than generic binding. This does not assert that every co-complex pair is a direct binary contact. |
| GO:0005515 protein binding | IPI PMID:15102850 Identification of snapin and three novel proteins (BLOS1, BL... | KEEP AS NON CORE | Summary: BLOS1 association with BLOC1S6/pallidin is compatible with BLOC-1 assembly. Reason: PMID:15102850 identifies endogenous BLOS1 in the same BLOC-1 complex as the listed partner and reports a binary-interaction network. The canonical cache is abstract-only, so the individual pair experiment has not been independently reconstructed. Retain the curator-supported physical association as non-core; the assembled trafficking complex is more informative than generic binding. This does not assert that every co-complex pair is a direct binary contact. |
| GO:0005515 protein binding | IPI PMID:22203680 Assembly and architecture of biogenesis of lysosome-related ... | KEEP AS NON CORE | Summary: BLOC-1 association with SNAPIN is retained. Reason: PMID:22203680 establishes the eight-subunit BLOC-1 assembly and stable subcomplexes. The partner is in the same eight-subunit assembly; the selected structural Results and Discussion do not by themselves reconstruct this exact binary interaction. Retain the existing IPI association as non-core without converting shared assembly into an unsupported pairwise contact or intrinsic adapter activity. The canonical abstract and selected official primary full-text passages are distinguished. Supporting Evidence: |
| GO:0005515 protein binding | IPI PMID:22203680 Assembly and architecture of biogenesis of lysosome-related ... | KEEP AS NON CORE | Summary: BLOC-1 association with BLOC1S2/BLOS2 is retained. Reason: PMID:22203680 establishes the eight-subunit BLOC-1 assembly and stable subcomplexes. The partner is in the same eight-subunit assembly; the selected structural Results and Discussion do not by themselves reconstruct this exact binary interaction. Retain the existing IPI association as non-core without converting shared assembly into an unsupported pairwise contact or intrinsic adapter activity. The canonical abstract and selected official primary full-text passages are distinguished. Supporting Evidence: |
| GO:0005515 protein binding | IPI PMID:22203680 Assembly and architecture of biogenesis of lysosome-related ... | KEEP AS NON CORE | Summary: BLOC-1 association with BLOC1S6/pallidin is retained. Reason: PMID:22203680 establishes the eight-subunit BLOC-1 assembly and stable subcomplexes. BLOS1 and pallidin are in the same experimentally reconstituted pallidin-Cappuccino-BLOS1 trimer. Retain the existing IPI association as non-core without converting shared assembly into an unsupported pairwise contact or intrinsic adapter activity. The canonical abstract and selected official primary full-text passages are distinguished. Supporting Evidence: |
| GO:0005515 protein binding | IPI PMID:22309213 Identification of a molecular component of the mitochondrial... | KEEP AS NON CORE | Summary: GCN5L1 associates with the respiratory-chain target ATP5F1A. Reason: PMID:22309213 reports interaction with respiratory-chain acetylation targets. Selected full-text co-immunoprecipitation experiments, read separately from the abstract-only canonical cache, support the listed interaction. Retain generic binding as non-core support for the acetylation-regulatory role; it does not establish purified acetyltransferase chemistry. Supporting Evidence: |
| GO:0005515 protein binding | IPI PMID:22309213 Identification of a molecular component of the mitochondrial... | KEEP AS NON CORE | Summary: GCN5L1 associates with the respiratory-chain target NDUFA9. Reason: PMID:22309213 reports interaction with respiratory-chain acetylation targets. Selected full-text co-immunoprecipitation experiments, read separately from the abstract-only canonical cache, support the listed interaction. Retain generic binding as non-core support for the acetylation-regulatory role; it does not establish purified acetyltransferase chemistry. Supporting Evidence: |
| GO:0005515 protein binding | IPI PMID:25416956 A proteome-scale map of the human interactome network. | KEEP AS NON CORE | Summary: The BLOS1-pallidin interaction is consistent with BLOC-1 architecture. Reason: The original source is a human binary-interactome screen. Independent reconstitution in PMID:22203680 places BLOS1 and pallidin in a stable trimer. Retain this supported generic interaction as non-core without claiming that the original screen supplement was inspected. |
| GO:0005515 protein binding | IPI PMID:25898167 BORC, a multisubunit complex that regulates lysosome positio... | KEEP AS NON CORE | Summary: BLOS1 participates in the eight-subunit BORC interaction assembly. Reason: PMID:25898167 uses affinity purification, co-isolation and recombinant assembly to identify BORC. The seven listed proteins are co-subunits of that complex; these experiments do not mean that BLOS1 directly binds every one of them in isolation. Retain the physical association as non-core and represent the structural trafficking role through BORC membership. Supporting Evidence: |
| GO:0005515 protein binding | IPI PMID:32296183 A reference map of the human binary protein interactome. | UNDECIDED | Summary: The reported BLOS1-HGS screen interaction remains unadjudicated. Reason: PMID:32296183 is a human binary-interactome study, and the source UniProt record lists this interaction. The exact pair-level primary screen record, confirmation experiment and relevant biological context were not inspected. Neither the broad paper abstract nor a generic binding label is a reason to remove an experimental assertion. Retain uncertainty until the specific pair evidence is available; the partner isoform identifier, where present, is preserved. The UniProt INTERACTION block records this pair with NbExp=3, which positively corroborates the reported association. That database count does not expose the primary pair-level confirmation or establish a more specific molecular activity; the remaining uncertainty concerns that assessment, not whether UniProt contains the pair. Supporting Evidence: |
| GO:0005515 protein binding | IPI PMID:32296183 A reference map of the human binary protein interactome. | UNDECIDED | Summary: The reported BLOS1-MAGEB4 screen interaction remains unadjudicated. Reason: PMID:32296183 is a human binary-interactome study, and the source UniProt record lists this interaction. The exact pair-level primary screen record, confirmation experiment and relevant biological context were not inspected. Neither the broad paper abstract nor a generic binding label is a reason to remove an experimental assertion. Retain uncertainty until the specific pair evidence is available; the partner isoform identifier, where present, is preserved. The UniProt INTERACTION block records this pair with NbExp=3, which positively corroborates the reported association. That database count does not expose the primary pair-level confirmation or establish a more specific molecular activity; the remaining uncertainty concerns that assessment, not whether UniProt contains the pair. Supporting Evidence: |
| GO:0005515 protein binding | IPI PMID:32296183 A reference map of the human binary protein interactome. | UNDECIDED | Summary: The reported BLOS1-SNAPC5 isoform O75971-2 screen interaction remains unadjudicated. Reason: PMID:32296183 is a human binary-interactome study, and the source UniProt record lists this interaction. The exact pair-level primary screen record, confirmation experiment and relevant biological context were not inspected. Neither the broad paper abstract nor a generic binding label is a reason to remove an experimental assertion. Retain uncertainty until the specific pair evidence is available; the partner isoform identifier, where present, is preserved. The UniProt INTERACTION block records this pair with NbExp=3, which positively corroborates the reported association. That database count does not expose the primary pair-level confirmation or establish a more specific molecular activity; the remaining uncertainty concerns that assessment, not whether UniProt contains the pair. Supporting Evidence: |
| GO:0005515 protein binding | IPI PMID:32296183 A reference map of the human binary protein interactome. | KEEP AS NON CORE | Summary: The screen interaction with SNAPIN has independent complex-level support. Reason: The PMID:32296183 pair record was not independently reconstructed, but the physical association is independently supported by BLOC-1 assembly studies. Retain the existing generic interaction as non-core; this is not a claim that all eight subunits contact one another directly. |
| GO:0005515 protein binding | IPI PMID:32296183 A reference map of the human binary protein interactome. | UNDECIDED | Summary: The reported BLOS1-DCTN2 screen interaction remains unadjudicated. Reason: PMID:32296183 is a human binary-interactome study, and the source UniProt record lists this interaction. The exact pair-level primary screen record, confirmation experiment and relevant biological context were not inspected. Neither the broad paper abstract nor a generic binding label is a reason to remove an experimental assertion. Retain uncertainty until the specific pair evidence is available; the partner isoform identifier, where present, is preserved. The UniProt INTERACTION block records this pair with NbExp=3, which positively corroborates the reported association. That database count does not expose the primary pair-level confirmation or establish a more specific molecular activity; the remaining uncertainty concerns that assessment, not whether UniProt contains the pair. Supporting Evidence: |
| GO:0005515 protein binding | IPI PMID:32296183 A reference map of the human binary protein interactome. | UNDECIDED | Summary: The reported BLOS1-USHBP1 screen interaction remains unadjudicated. Reason: PMID:32296183 is a human binary-interactome study, and the source UniProt record lists this interaction. The exact pair-level primary screen record, confirmation experiment and relevant biological context were not inspected. Neither the broad paper abstract nor a generic binding label is a reason to remove an experimental assertion. Retain uncertainty until the specific pair evidence is available; the partner isoform identifier, where present, is preserved. The UniProt INTERACTION block records this pair with NbExp=3, which positively corroborates the reported association. That database count does not expose the primary pair-level confirmation or establish a more specific molecular activity; the remaining uncertainty concerns that assessment, not whether UniProt contains the pair. Supporting Evidence: |
| GO:0005515 protein binding | IPI PMID:32296183 A reference map of the human binary protein interactome. | UNDECIDED | Summary: The reported BLOS1-FBXO44 isoform Q9H4M3-2 screen interaction remains unadjudicated. Reason: PMID:32296183 is a human binary-interactome study, and the source UniProt record lists this interaction. The exact pair-level primary screen record, confirmation experiment and relevant biological context were not inspected. Neither the broad paper abstract nor a generic binding label is a reason to remove an experimental assertion. Retain uncertainty until the specific pair evidence is available; the partner isoform identifier, where present, is preserved. The UniProt INTERACTION block records this pair with NbExp=3, which positively corroborates the reported association. That database count does not expose the primary pair-level confirmation or establish a more specific molecular activity; the remaining uncertainty concerns that assessment, not whether UniProt contains the pair. Supporting Evidence: |
| GO:0005515 protein binding | IPI PMID:32296183 A reference map of the human binary protein interactome. | KEEP AS NON CORE | Summary: The screen interaction with BLOC1S6/pallidin has independent complex-level support. Reason: The PMID:32296183 pair record was not independently reconstructed, but the physical association is independently supported by BLOC-1 assembly studies. Retain the existing generic interaction as non-core; this is not a claim that all eight subunits contact one another directly. |
| GO:0005515 protein binding | IPI PMID:33961781 Dual proteome-scale networks reveal cell-specific remodeling... | KEEP AS NON CORE | Summary: Co-complex recovery with SNAPIN agrees with BLOC-1 assembly. Reason: PMID:33961781 maps affinity-purification interaction networks; its association evidence need not denote direct binary contact. The listed pair is independently consistent with the experimentally established BLOC-1 complex. Retain generic binding as non-core without asserting a separately verified pair-level affinity-purification record or converting it into a specific adapter mechanism. |
| GO:0005515 protein binding | IPI PMID:33961781 Dual proteome-scale networks reveal cell-specific remodeling... | KEEP AS NON CORE | Summary: Co-complex recovery with BLOC1S2/BLOS2 agrees with BLOC-1 assembly. Reason: PMID:33961781 maps affinity-purification interaction networks; its association evidence need not denote direct binary contact. The listed pair is independently consistent with the experimentally established BLOC-1 complex. Retain generic binding as non-core without asserting a separately verified pair-level affinity-purification record or converting it into a specific adapter mechanism. |
| GO:0005515 protein binding | IPI PMID:33961781 Dual proteome-scale networks reveal cell-specific remodeling... | KEEP AS NON CORE | Summary: Co-complex recovery with BLOC1S6/pallidin agrees with BLOC-1 assembly. Reason: PMID:33961781 maps affinity-purification interaction networks; its association evidence need not denote direct binary contact. The listed pair is independently consistent with the experimentally established BLOC-1 complex. Retain generic binding as non-core without asserting a separately verified pair-level affinity-purification record or converting it into a specific adapter mechanism. |
| GO:0005576 extracellular region | HDA PMID:23580065 Shotgun proteomics reveals specific modulated protein patter... | UNDECIDED | Summary: The extracellular assignment from human tear proteomics is unresolved. Reason: PMID:23580065 concerns human tear proteomics, but the available abstract does not identify the BLOC1S1 peptide/protein result and the relevant protein table was not accessed. Intracellular BLOC1S1 functions do not disprove detection in this sample. Preserve the experimental HDA assertion as undecided rather than removing it from the title or abstract alone. Supporting Evidence: |
| GO:0005758 mitochondrial intermembrane space | IDA PMID:22309213 Identification of a molecular component of the mitochondrial... | ACCEPT | Summary: A mitochondrial BLOC1S1 pool is associated with the mitochondrial intermembrane space. Reason: PMID:22309213 combines tagged human HepG2 mitochondrial localization with endogenous mouse fractionation and immuno-electron microscopy resolving mitochondrial subcompartments. The selected full-text experiments support this conserved localization; the precise subcompartment evidence is not described as endogenous human immuno-electron microscopy. The canonical cache remains abstract-only. Supporting Evidence: |
| GO:0005758 mitochondrial intermembrane space | IEA GO_REF:0000120 | ACCEPT | Summary: The mapped mitochondrial intermembrane space localization is supported by direct mitochondrial evidence. Reason: This combined electronic assignment is consistent with PMID:22309213 and the source UniProt location record. Human cell mitochondrial localization and mouse subcompartment experiments are distinguished. Retain the location without inferring that all BLOC1S1 molecules or both isoforms are exclusively mitochondrial. Supporting Evidence: |
| GO:0005759 mitochondrial matrix | IDA PMID:22309213 Identification of a molecular component of the mitochondrial... | ACCEPT | Summary: A mitochondrial BLOC1S1 pool is associated with the mitochondrial matrix. Reason: PMID:22309213 combines tagged human HepG2 mitochondrial localization with endogenous mouse fractionation and immuno-electron microscopy resolving mitochondrial subcompartments. The selected full-text experiments support this conserved localization; the precise subcompartment evidence is not described as endogenous human immuno-electron microscopy. The canonical cache remains abstract-only. Supporting Evidence: |
| GO:0005759 mitochondrial matrix | IEA GO_REF:0000120 | ACCEPT | Summary: The mapped mitochondrial matrix localization is supported by direct mitochondrial evidence. Reason: This combined electronic assignment is consistent with PMID:22309213 and the source UniProt location record. Human cell mitochondrial localization and mouse subcompartment experiments are distinguished. Retain the location without inferring that all BLOC1S1 molecules or both isoforms are exclusively mitochondrial. Supporting Evidence: |
| GO:0005765 lysosomal membrane | IEA GO_REF:0000044 | MODIFY | Summary: Refine lysosomal membrane association to its cytoplasmic face. Reason: The UniProt subcellular-location mapping identifies lysosomal membrane association. Independent BORC experiments in PMID:25898167 support peripheral association on the cytoplasmic surface, making GO:0098574 more precise than the whole membrane. This is a refinement to the location already represented by source row53, not a new process or an assertion of integral membrane insertion. Proposed replacements: cytoplasmic side of lysosomal membrane Supporting Evidence: |
| GO:0005765 lysosomal membrane | TAS Reactome:R-HSA-429815 | MODIFY | Summary: Refine lysosomal membrane association to its cytoplasmic face. Reason: Reactome:R-HSA-429815 describes BLOC-1 complex formation and does not establish lysosomal localization at all. PMID:25898167 distinguishes lysosome-associated BORC from BLOC-1 and independently supports peripheral BLOC1S1 association on the cytoplasmic surface as a BORC subunit. GO:0098574 is therefore supported by the BORC evidence, not by the BLOC-1 assembly event. The original TAS source remains preserved. This refines the location already represented by source row53; it does not assert integral membrane insertion or add a new process. Proposed replacements: cytoplasmic side of lysosomal membrane Supporting Evidence: |
| GO:0005769 early endosome | IEA GO_REF:0000107 | ACCEPT | Summary: BLOC-1-associated BLOS1 participates at early endosomes. Reason: The electronic mouse-to-human localization agrees with BLOC-1 function and PMID:16837549. The selected primary localization experiments use pallidin/dysbindin antibodies in human MNT-1 cells to localize the complex to early-endosomal tubules; this is complex localization, not a claim of a BLOS1-specific antibody experiment. Membership and endosomal assembly evidence support retention. |
| GO:0005829 cytosol | IDA PMID:22309213 Identification of a molecular component of the mitochondrial... | ACCEPT | Summary: BLOC1S1 has a cytosolic pool as well as membrane-associated and mitochondrial pools. Reason: PMID:22309213 identifies cytosolic GCN5L1 alongside its mitochondrial enrichment; selected fractionation evidence and the UniProt record agree. Cytosolic localization is consistent with reversible association of the trafficking complexes and is not contradicted by mitochondrial targeting. Supporting Evidence: |
| GO:0005829 cytosol | IEA GO_REF:0000120 | ACCEPT | Summary: BLOC1S1 has a cytosolic pool as well as membrane-associated and mitochondrial pools. Reason: PMID:22309213 identifies cytosolic GCN5L1 alongside its mitochondrial enrichment; selected fractionation evidence and the UniProt record agree. Cytosolic localization is consistent with reversible association of the trafficking complexes and is not contradicted by mitochondrial targeting. Supporting Evidence: |
| GO:0008089 anterograde axonal transport | IEA GO_REF:0000107 | KEEP AS NON CORE | Summary: Retain the neuronal cargo-transport role as a context-specific BLOC-1 function. Reason: The actual MGI Bloc1s1 donor graph includes experimental support from PMID:21998198. Selected primary experiments establish BLOC-1/AP-3-dependent PI4KIIalpha cargo sorting from neuronal cell bodies to neurites, using dysbindin-deficient mouse neurons and complementary rat PC12 cargo experiments. They support the complex role inherited by its structural subunit, not BLOS1 acting as a motor or a BLOS1-specific neuronal knockout. Retain the orthology-based assertion as non-core. |
| GO:0008089 anterograde axonal transport | ISS GO_REF:0000024 | KEEP AS NON CORE | Summary: Retain the neuronal cargo-transport role as a context-specific BLOC-1 function. Reason: The actual MGI Bloc1s1 donor graph includes experimental support from PMID:21998198. Selected primary experiments establish BLOC-1/AP-3-dependent PI4KIIalpha cargo sorting from neuronal cell bodies to neurites, using dysbindin-deficient mouse neurons and complementary rat PC12 cargo experiments. They support the complex role inherited by its structural subunit, not BLOS1 acting as a motor or a BLOS1-specific neuronal knockout. Retain the orthology-based assertion as non-core. |
| GO:0009060 aerobic respiration | IMP PMID:22309213 Identification of a molecular component of the mitochondrial... | MODIFY | Summary: GCN5L1 regulates respiratory activity rather than constituting the respiratory electron-transfer machinery. Reason: In PMID:22309213, GCN5L1 knockdown reduces mitochondrial target acetylation and increases respiratory activity in the tested human cell system; reconstitution and SIRT3 comparisons support counter-regulation. The more precise process is negative regulation of cellular respiration (GO:1901856). This interpretation uses the actual Results, not the inconsistent wording of a Results heading, and is restricted to the tested regulatory context. Proposed replacements: negative regulation of cellular respiration Supporting Evidence: |
| GO:0016197 endosomal transport | IBA GO_REF:0000033 | ACCEPT | Summary: Endosomal transport is a core BLOC-1 trafficking role. Reason: The PAINT assertion is consistent with experimentally established BLOC-1 endosomal cargo trafficking and BLOS1 assembly participation. No target-specific loss or incompatible clade placement has been established. The fly/worm source list is not scored by donor count and is not treated as a pairwise similarity transfer; the exact PTN source remains unchanged. |
| GO:0031083 BLOC-1 complex | IBA GO_REF:0000033 | ACCEPT | Summary: Conserved BLOC-1 membership is supported directly in human-containing assembly experiments. Reason: The inherited PAINT assertion agrees with direct BLOS1 biochemical membership and reconstitution. Human P78537 appearing among the descendant evidence is expected and is not circular support. No phylogenetic loss or incorrect ancestral placement is asserted; the original PTN and all supporting entities remain intact. |
| GO:0031083 BLOC-1 complex | IDA PMID:15102850 Identification of snapin and three novel proteins (BLOS1, BL... | ACCEPT | Summary: BLOS1 is an integral BLOC-1 subunit. Reason: Endogenous co-immunoprecipitation/fractionation and recombinant eight-subunit assembly identify BLOS1 as part of BLOC-1. The stable pallidin-Cappuccino-BLOS1 trimer further defines its assembly context. Retain complex membership as core, keeping BLOC-1 separate from the related BORC complex. Supporting Evidence: |
| GO:0031083 BLOC-1 complex | IDA PMID:22203680 Assembly and architecture of biogenesis of lysosome-related ... | ACCEPT | Summary: BLOS1 is an integral BLOC-1 subunit. Reason: Endogenous co-immunoprecipitation/fractionation and recombinant eight-subunit assembly identify BLOS1 as part of BLOC-1. The stable pallidin-Cappuccino-BLOS1 trimer further defines its assembly context. Retain complex membership as core, keeping BLOC-1 separate from the related BORC complex. Supporting Evidence: |
| GO:0031083 BLOC-1 complex | IEA GO_REF:0000120 | ACCEPT | Summary: BLOS1 is an integral BLOC-1 subunit. Reason: Endogenous co-immunoprecipitation/fractionation and recombinant eight-subunit assembly identify BLOS1 as part of BLOC-1. The stable pallidin-Cappuccino-BLOS1 trimer further defines its assembly context. Retain complex membership as core, keeping BLOC-1 separate from the related BORC complex. |
| GO:0031083 BLOC-1 complex | IPI PMID:22203680 Assembly and architecture of biogenesis of lysosome-related ... | ACCEPT | Summary: BLOS1 is an integral BLOC-1 subunit. Reason: Endogenous co-immunoprecipitation/fractionation and recombinant eight-subunit assembly identify BLOS1 as part of BLOC-1. The stable pallidin-Cappuccino-BLOS1 trimer further defines its assembly context. Retain complex membership as core, keeping BLOC-1 separate from the related BORC complex. Supporting Evidence: |
| GO:0031175 neuron projection development | ISS GO_REF:0000024 | KEEP AS NON CORE | Summary: Neurite development is a context-specific consequence of BLOC-1 trafficking. Reason: PMID:19546860 reports impaired neurite outgrowth in primary hippocampal cultures from pallid mice lacking functional BLOC-1. It supports the complex-level neuronal role and the orthology-based annotation, while not establishing a BLOS1-specific neuronal perturbation. Retain this developmental outcome as non-core rather than infer a direct neurite-growth enzyme or remove it because another subunit was the experimental lesion. |
| GO:0032418 lysosome localization | IMP PMID:25898167 BORC, a multisubunit complex that regulates lysosome positio... | ACCEPT | Summary: BLOS1-containing BORC supports outward lysosome positioning. Reason: PMID:25898167 directly shows that human HeLa BLOS1 depletion causes juxtanuclear lysosome clustering and loss or reduction of lysosomal Arl8b. Shared-subunit depletion also destabilizes BORC. Thus BLOS1 performs structural work in the positioning machinery; it is not simply cargo whose movement is measured. Retain lysosome localization as core without assigning kinesin motor activity to BLOS1. Supporting Evidence: |
| GO:0032418 lysosome localization | NAS PMID:25898167 BORC, a multisubunit complex that regulates lysosome positio... | ACCEPT | Summary: BLOS1-containing BORC supports outward lysosome positioning. Reason: PMID:25898167 directly shows that human HeLa BLOS1 depletion causes juxtanuclear lysosome clustering and loss or reduction of lysosomal Arl8b. Shared-subunit depletion also destabilizes BORC. Thus BLOS1 performs structural work in the positioning machinery; it is not simply cargo whose movement is measured. Retain lysosome localization as core without assigning kinesin motor activity to BLOS1. Supporting Evidence: |
| GO:0032438 melanosome organization | NAS PMID:15102850 Identification of snapin and three novel proteins (BLOS1, BL... | ACCEPT | Summary: Melanosome organization is supported through the BLOC-1 assembly. Reason: BLOS1 is an experimentally established structural component of BLOC-1, the endosomal trafficking machinery required for melanosome biogenesis. The annotation reflects participation through this assembly, supported by complex architecture and cargo-trafficking experiments; it does not claim that the cited paper performed a BLOS1-specific patient or melanocyte knockout experiment. The original NAS evidence and reference remain unchanged. |
| GO:0032438 melanosome organization | NAS PMID:22203680 Assembly and architecture of biogenesis of lysosome-related ... | ACCEPT | Summary: Melanosome organization is supported through the BLOC-1 assembly. Reason: BLOS1 is an experimentally established structural component of BLOC-1, the endosomal trafficking machinery required for melanosome biogenesis. The annotation reflects participation through this assembly, supported by complex architecture and cargo-trafficking experiments; it does not claim that the cited paper performed a BLOS1-specific patient or melanocyte knockout experiment. The original NAS evidence and reference remain unchanged. |
| GO:0048490 anterograde synaptic vesicle transport | IEA GO_REF:0000107 | KEEP AS NON CORE | Summary: Retain the specific neuronal vesicle-cargo role at complex level. Reason: The official MGI donor graph links this term to PMID:21998198. The selected experiments concern BLOC-1/AP-3-dependent delivery of the neuronal membrane cargo PI4KIIalpha, not a universal requirement for transport of every synaptic vesicle protein. Retain the curated orthology-based role as non-core with this cargo/context limitation. BLOC-1 neuronal sorting must not be conflated with BORC-mediated lysosome transport. |
| GO:0048490 anterograde synaptic vesicle transport | ISS GO_REF:0000024 | KEEP AS NON CORE | Summary: Retain the specific neuronal vesicle-cargo role at complex level. Reason: The official MGI donor graph links this term to PMID:21998198. The selected experiments concern BLOC-1/AP-3-dependent delivery of the neuronal membrane cargo PI4KIIalpha, not a universal requirement for transport of every synaptic vesicle protein. Retain the curated orthology-based role as non-core with this cargo/context limitation. BLOC-1 neuronal sorting must not be conflated with BORC-mediated lysosome transport. |
| GO:0051036 regulation of endosome size | NAS PMID:31314175 Biogenesis of lysosome-related organelles complex-1 (BORC) r... | UNDECIDED | Summary: The BLOS1-specific assignment to endosome size regulation remains unresolved. Reason: PMID:31314175 establishes BORC-dependent late endosomal/lysosomal size regulation, with distinct effects among experimentally compared subunits. The selected Diaskedin/Myrlysin/Lyspersin comparisons show that shared positioning defects do not imply a shared size phenotype. BLOS1 membership is compatible with the assignment but does not establish its specific participation in this size mechanism. Preserve uncertainty; no negative BLOS1 result or whole-paper absence claim is inferred. Supporting Evidence: |
| GO:0060155 platelet dense granule organization | NAS PMID:15102850 Identification of snapin and three novel proteins (BLOS1, BL... | ACCEPT | Summary: BLOS1 contributes to platelet dense-granule biogenesis through BLOC-1. Reason: PMID:15102850 establishes BLOS1 as a structural component of the complex needed for lysosome-related organelle biogenesis, including platelet dense granules. This is a conserved complex-participation NAS assertion, supported by assembly dependence rather than a claim of a BLOS1-specific platelet assay in that paper. Retain the specialized organelle-biogenesis role while distinguishing it from BORC lysosome positioning. |
| GO:0061733 protein-lysine-acetyltransferase activity | IMP PMID:38281616 GCN5L1-mediated acetylation prevents Rictor degradation in c... | UNDECIDED | Summary: GCN5L1-dependent acetylation is supported, but the intrinsic catalytic-site assignment remains unresolved. Reason: The enables qualifier for GO:0061733 assigns acetyl transfer from acetyl-CoA to a protein lysine to BLOC1S1 itself. PMID:38281616 shows that GCN5L1 perturbation in human AC16 cells changes Rictor acetylation and stability, but measures cellular acetylation and leaves catalytic-null mutant analysis for future work. Earlier recombinant add-back experiments require native mitochondrial factors. Those data do not distinguish whether GCN5L1 supplies the catalytic site or supports another catalytic component; cofactor dependence does not disprove catalysis. Retain the experimental assertion as undecided rather than remove it or invent a catalytic complex. The limitation is that the particular cellular perturbation assays do not isolate the acetyl-transfer step, rather than that an IMP code categorically excludes molecular-function inference. |
| GO:0062196 regulation of lysosome size | NAS PMID:31314175 Biogenesis of lysosome-related organelles complex-1 (BORC) r... | UNDECIDED | Summary: The BLOS1-specific assignment to lysosome size regulation remains unresolved. Reason: PMID:31314175 establishes BORC-dependent late endosomal/lysosomal size regulation, with distinct effects among experimentally compared subunits. The selected Diaskedin/Myrlysin/Lyspersin comparisons show that shared positioning defects do not imply a shared size phenotype. BLOS1 membership is compatible with the assignment but does not establish its specific participation in this size mechanism. Preserve uncertainty; no negative BLOS1 result or whole-paper absence claim is inferred. Supporting Evidence: |
| GO:0072384 organelle transport along microtubule | NAS PMID:25898167 BORC, a multisubunit complex that regulates lysosome positio... | ACCEPT | Summary: BLOS1 supports microtubule-based lysosome transport through BORC. Reason: PMID:25898167 establishes the BORC-Arl8-kinesin pathway for centrifugal lysosome movement. BLOS1 depletion destabilizes BORC and disrupts lysosomal Arl8 recruitment and distribution, linking this subunit to the transport apparatus. Retain the process as structural participation in motor recruitment, without assigning ATPase or motor activity to BLOS1 itself. Supporting Evidence: |
| GO:0098574 cytoplasmic side of lysosomal membrane | NAS PMID:25898167 BORC, a multisubunit complex that regulates lysosome positio... | ACCEPT | Summary: The BORC-associated BLOS1 pool acts on the cytoplasmic side of lysosomes. Reason: The BORC localization and lysosome-purification experiments in PMID:25898167 support peripheral association with the cytoplasmic face of the lysosomal membrane. Tagged-myrlysin localization, BLOS1 co-complex membership and lysosomal proteomics are distinguished from a BLOS1-specific imaging experiment. This is the relevant spatial context for cytosolic ARL8/kinesin recruitment. Supporting Evidence: |
| GO:0099078 BORC complex | IDA PMID:25898167 BORC, a multisubunit complex that regulates lysosome positio... | ACCEPT | Summary: BLOS1 is an integral BORC subunit. Reason: PMID:25898167 identifies BLOS1 with BLOS2, SNAPIN, KXD1, myrlysin, lyspersin, diaskedin and MEF2BNB in BORC by affinity purification/co-isolation and recombinant assembly. Shared-subunit depletion reduces the abundance of BORC-specific myrlysin. Retain core membership while distinguishing the three shared subunits from the separate BLOC-1 assembly. Supporting Evidence: |
| GO:0099078 BORC complex | IPI PMID:25898167 BORC, a multisubunit complex that regulates lysosome positio... | ACCEPT | Summary: BLOS1 is an integral BORC subunit. Reason: PMID:25898167 identifies BLOS1 with BLOS2, SNAPIN, KXD1, myrlysin, lyspersin, diaskedin and MEF2BNB in BORC by affinity purification/co-isolation and recombinant assembly. Shared-subunit depletion reduces the abundance of BORC-specific myrlysin. Retain core membership while distinguishing the three shared subunits from the separate BLOC-1 assembly. Supporting Evidence: |
| GO:1904115 axon cytoplasm | IEA GO_REF:0000108 | KEEP AS NON CORE | Summary: Axonal localization is retained as a derived neuronal-context assignment. Reason: The GO_REF:0000108 assertion is logically derived from the retained anterograde axonal transport annotation. It is compatible with the BLOC-1 neuronal cargo pathway, but is not independent BLOS1-specific axonal imaging evidence. Retain as non-core and do not treat the computational derivation as an additional experimental confirmation. Supporting Evidence: |
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Download this section (compressed HTML)Q: Which residues or partner proteins provide the acetyl-transfer catalytic site in the GCN5L1-dependent mitochondrial and Rictor acetylation systems?
Q: Does BLOS1 participate in the BORC-dependent organelle-size mechanism, and can that role be separated from its established effects on complex stability and positioning?
Q: Which primary pair-level records substantiate the six context-unresolved HuRI interactions, and which experiments distinguish direct contact from co-complex association?
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