Vas2 (Aps1) is the sigma subunit of the heterotetrameric AP-1 clathrin adaptor complex. It associates with the gamma subunit Apl4 and contributes to assembly and membrane recruitment of AP-1 at the Golgi and endosomal system. The complex sorts membrane-protein cargo into intracellular transport carriers and supports exit of cargo such as the v-SNARE Syb1 from endosomes.
HDA PMID:16823372 ORFeome cloning and global analysis of protein localization ...
KEEP AS NON CORE
Summary: nucleus is retained as an ancillary annotation.
Reason: Retain the reported nuclear signal from the tagged-protein screen as an ancillary localization. It does not establish a nuclear AP-1 cargo-sorting mechanism and is not the principal functional location supported by endosomal trafficking experiments.
Next, we determined the localization of 4,431 proteins, corresponding to approximately 90% of the fission yeast proteome, by tagging each ORF with the yellow fluorescent protein.
In pull-down assay, Apm1 binds Apl2 even in the absence of Aps1 and Apl4, and Apl4 binds Aps1 even in the absence of Apm1 and Apl2. Consistently, the deletion of any subunit generally caused the disassociation of the heterotetrameric complex from endosomes, although some subunits weakly localized to endosomes. In addition, the deletion of individual subunits caused similar endosomal accumulation of v-SNARE synaptobrevin Syb1. Altogether, results suggest that the four subunits are all essential for the heterotetrameric complex formation and for the AP-1 function in exit transport from endosomes.
Summary: nucleus is retained as an ancillary annotation.
Reason: Retain the reported nuclear signal from the tagged-protein screen as an ancillary localization. It does not establish a nuclear AP-1 cargo-sorting mechanism and is not the principal functional location supported by endosomal trafficking experiments.
Next, we determined the localization of 4,431 proteins, corresponding to approximately 90% of the fission yeast proteome, by tagging each ORF with the yellow fluorescent protein.
In pull-down assay, Apm1 binds Apl2 even in the absence of Aps1 and Apl4, and Apl4 binds Aps1 even in the absence of Apm1 and Apl2. Consistently, the deletion of any subunit generally caused the disassociation of the heterotetrameric complex from endosomes, although some subunits weakly localized to endosomes. In addition, the deletion of individual subunits caused similar endosomal accumulation of v-SNARE synaptobrevin Syb1. Altogether, results suggest that the four subunits are all essential for the heterotetrameric complex formation and for the AP-1 function in exit transport from endosomes.
EXP PMID:16823372 ORFeome cloning and global analysis of protein localization ...
ACCEPT
Summary: cytoplasm is supported.
Reason: AP-1 is a peripheral membrane adaptor recruited from the cytoplasm. Cytoplasmic and cytosolic pools are consistent with the localization screen and the membrane recruitment behavior of the complex.
Next, we determined the localization of 4,431 proteins, corresponding to approximately 90% of the fission yeast proteome, by tagging each ORF with the yellow fluorescent protein.
In pull-down assay, Apm1 binds Apl2 even in the absence of Aps1 and Apl4, and Apl4 binds Aps1 even in the absence of Apm1 and Apl2. Consistently, the deletion of any subunit generally caused the disassociation of the heterotetrameric complex from endosomes, although some subunits weakly localized to endosomes. In addition, the deletion of individual subunits caused similar endosomal accumulation of v-SNARE synaptobrevin Syb1. Altogether, results suggest that the four subunits are all essential for the heterotetrameric complex formation and for the AP-1 function in exit transport from endosomes.
Reason: AP-1 is a peripheral membrane adaptor recruited from the cytoplasm. Cytoplasmic and cytosolic pools are consistent with the localization screen and the membrane recruitment behavior of the complex.
Next, we determined the localization of 4,431 proteins, corresponding to approximately 90% of the fission yeast proteome, by tagging each ORF with the yellow fluorescent protein.
In pull-down assay, Apm1 binds Apl2 even in the absence of Aps1 and Apl4, and Apl4 binds Aps1 even in the absence of Apm1 and Apl2. Consistently, the deletion of any subunit generally caused the disassociation of the heterotetrameric complex from endosomes, although some subunits weakly localized to endosomes. In addition, the deletion of individual subunits caused similar endosomal accumulation of v-SNARE synaptobrevin Syb1. Altogether, results suggest that the four subunits are all essential for the heterotetrameric complex formation and for the AP-1 function in exit transport from endosomes.
IDA PMID:19624755 Deletion mutants of AP-1 adaptin subunits display distinct p...
ACCEPT
Summary: endosome is supported.
Reason: Fission yeast AP-1 subunit deletions alter recruitment to endosomes and trap Syb1 in the endosomal system. The Golgi/endosome-associated clathrin adaptor location is consistent with the conserved AP-1 coat function and the curated target-specific localization observations.
In pull-down assay, Apm1 binds Apl2 even in the absence of Aps1 and Apl4, and Apl4 binds Aps1 even in the absence of Apm1 and Apl2. Consistently, the deletion of any subunit generally caused the disassociation of the heterotetrameric complex from endosomes, although some subunits weakly localized to endosomes. In addition, the deletion of individual subunits caused similar endosomal accumulation of v-SNARE synaptobrevin Syb1. Altogether, results suggest that the four subunits are all essential for the heterotetrameric complex formation and for the AP-1 function in exit transport from endosomes.
Reason: Fission yeast AP-1 subunit deletions alter recruitment to endosomes and trap Syb1 in the endosomal system. The Golgi/endosome-associated clathrin adaptor location is consistent with the conserved AP-1 coat function and the curated target-specific localization observations.
In pull-down assay, Apm1 binds Apl2 even in the absence of Aps1 and Apl4, and Apl4 binds Aps1 even in the absence of Apm1 and Apl2. Consistently, the deletion of any subunit generally caused the disassociation of the heterotetrameric complex from endosomes, although some subunits weakly localized to endosomes. In addition, the deletion of individual subunits caused similar endosomal accumulation of v-SNARE synaptobrevin Syb1. Altogether, results suggest that the four subunits are all essential for the heterotetrameric complex formation and for the AP-1 function in exit transport from endosomes.
IDA PMID:19624755 Deletion mutants of AP-1 adaptin subunits display distinct p...
ACCEPT
Summary: Golgi apparatus is supported.
Reason: Fission yeast AP-1 subunit deletions alter recruitment to endosomes and trap Syb1 in the endosomal system. The Golgi/endosome-associated clathrin adaptor location is consistent with the conserved AP-1 coat function and the curated target-specific localization observations.
In pull-down assay, Apm1 binds Apl2 even in the absence of Aps1 and Apl4, and Apl4 binds Aps1 even in the absence of Apm1 and Apl2. Consistently, the deletion of any subunit generally caused the disassociation of the heterotetrameric complex from endosomes, although some subunits weakly localized to endosomes. In addition, the deletion of individual subunits caused similar endosomal accumulation of v-SNARE synaptobrevin Syb1. Altogether, results suggest that the four subunits are all essential for the heterotetrameric complex formation and for the AP-1 function in exit transport from endosomes.
Reason: Fission yeast AP-1 subunit deletions alter recruitment to endosomes and trap Syb1 in the endosomal system. The Golgi/endosome-associated clathrin adaptor location is consistent with the conserved AP-1 coat function and the curated target-specific localization observations.
In pull-down assay, Apm1 binds Apl2 even in the absence of Aps1 and Apl4, and Apl4 binds Aps1 even in the absence of Apm1 and Apl2. Consistently, the deletion of any subunit generally caused the disassociation of the heterotetrameric complex from endosomes, although some subunits weakly localized to endosomes. In addition, the deletion of individual subunits caused similar endosomal accumulation of v-SNARE synaptobrevin Syb1. Altogether, results suggest that the four subunits are all essential for the heterotetrameric complex formation and for the AP-1 function in exit transport from endosomes.
HDA PMID:16823372 ORFeome cloning and global analysis of protein localization ...
ACCEPT
Summary: cytosol is supported.
Reason: AP-1 is a peripheral membrane adaptor recruited from the cytoplasm. Cytoplasmic and cytosolic pools are consistent with the localization screen and the membrane recruitment behavior of the complex.
Next, we determined the localization of 4,431 proteins, corresponding to approximately 90% of the fission yeast proteome, by tagging each ORF with the yellow fluorescent protein.
In pull-down assay, Apm1 binds Apl2 even in the absence of Aps1 and Apl4, and Apl4 binds Aps1 even in the absence of Apm1 and Apl2. Consistently, the deletion of any subunit generally caused the disassociation of the heterotetrameric complex from endosomes, although some subunits weakly localized to endosomes. In addition, the deletion of individual subunits caused similar endosomal accumulation of v-SNARE synaptobrevin Syb1. Altogether, results suggest that the four subunits are all essential for the heterotetrameric complex formation and for the AP-1 function in exit transport from endosomes.
Summary: intercellular transport is not supported for this gene.
Reason: GO:0010496 means movement between cells, as verified in QuickGO. The experimentally established Vas2/AP-1 pathway sorts cargo between compartments inside a cell. This ARBA assertion conflates intercellular and intracellular transport and lacks an independent intercellular mechanism.
In pull-down assay, Apm1 binds Apl2 even in the absence of Aps1 and Apl4, and Apl4 binds Aps1 even in the absence of Apm1 and Apl2. Consistently, the deletion of any subunit generally caused the disassociation of the heterotetrameric complex from endosomes, although some subunits weakly localized to endosomes. In addition, the deletion of individual subunits caused similar endosomal accumulation of v-SNARE synaptobrevin Syb1. Altogether, results suggest that the four subunits are all essential for the heterotetrameric complex formation and for the AP-1 function in exit transport from endosomes.
Reason: The Aps1 sigma subunit is required for normal AP-1 complex formation and exit transport from endosomes; loss of individual subunits causes endosomal accumulation of Syb1. Retain the curated routes supported by the original target experiments and distinguish them from transport between cells.
In pull-down assay, Apm1 binds Apl2 even in the absence of Aps1 and Apl4, and Apl4 binds Aps1 even in the absence of Apm1 and Apl2. Consistently, the deletion of any subunit generally caused the disassociation of the heterotetrameric complex from endosomes, although some subunits weakly localized to endosomes. In addition, the deletion of individual subunits caused similar endosomal accumulation of v-SNARE synaptobrevin Syb1. Altogether, results suggest that the four subunits are all essential for the heterotetrameric complex formation and for the AP-1 function in exit transport from endosomes.
Reason: The Aps1 sigma subunit is required for normal AP-1 complex formation and exit transport from endosomes; loss of individual subunits causes endosomal accumulation of Syb1. Retain the curated routes supported by the original target experiments and distinguish them from transport between cells.
In pull-down assay, Apm1 binds Apl2 even in the absence of Aps1 and Apl4, and Apl4 binds Aps1 even in the absence of Apm1 and Apl2. Consistently, the deletion of any subunit generally caused the disassociation of the heterotetrameric complex from endosomes, although some subunits weakly localized to endosomes. In addition, the deletion of individual subunits caused similar endosomal accumulation of v-SNARE synaptobrevin Syb1. Altogether, results suggest that the four subunits are all essential for the heterotetrameric complex formation and for the AP-1 function in exit transport from endosomes.
Reason: The Aps1 sigma subunit is required for normal AP-1 complex formation and exit transport from endosomes; loss of individual subunits causes endosomal accumulation of Syb1. Retain the curated routes supported by the original target experiments and distinguish them from transport between cells.
In pull-down assay, Apm1 binds Apl2 even in the absence of Aps1 and Apl4, and Apl4 binds Aps1 even in the absence of Apm1 and Apl2. Consistently, the deletion of any subunit generally caused the disassociation of the heterotetrameric complex from endosomes, although some subunits weakly localized to endosomes. In addition, the deletion of individual subunits caused similar endosomal accumulation of v-SNARE synaptobrevin Syb1. Altogether, results suggest that the four subunits are all essential for the heterotetrameric complex formation and for the AP-1 function in exit transport from endosomes.
IDA PMID:19624755 Deletion mutants of AP-1 adaptin subunits display distinct p...
ACCEPT
Summary: AP-1 adaptor complex is supported.
Reason: Pull-downs establish the Apl4-Aps1 association, and subunit deletion analysis establishes their contribution to assembly and recruitment of the heterotetrameric AP-1 complex.
In pull-down assay, Apm1 binds Apl2 even in the absence of Aps1 and Apl4, and Apl4 binds Aps1 even in the absence of Apm1 and Apl2. Consistently, the deletion of any subunit generally caused the disassociation of the heterotetrameric complex from endosomes, although some subunits weakly localized to endosomes. In addition, the deletion of individual subunits caused similar endosomal accumulation of v-SNARE synaptobrevin Syb1. Altogether, results suggest that the four subunits are all essential for the heterotetrameric complex formation and for the AP-1 function in exit transport from endosomes.
Reason: Pull-downs establish the Apl4-Aps1 association, and subunit deletion analysis establishes their contribution to assembly and recruitment of the heterotetrameric AP-1 complex.
In pull-down assay, Apm1 binds Apl2 even in the absence of Aps1 and Apl4, and Apl4 binds Aps1 even in the absence of Apm1 and Apl2. Consistently, the deletion of any subunit generally caused the disassociation of the heterotetrameric complex from endosomes, although some subunits weakly localized to endosomes. In addition, the deletion of individual subunits caused similar endosomal accumulation of v-SNARE synaptobrevin Syb1. Altogether, results suggest that the four subunits are all essential for the heterotetrameric complex formation and for the AP-1 function in exit transport from endosomes.
NAS PMID:19624755 Deletion mutants of AP-1 adaptin subunits display distinct p...
ACCEPT
Summary: AP-1 adaptor complex is supported.
Reason: Pull-downs establish the Apl4-Aps1 association, and subunit deletion analysis establishes their contribution to assembly and recruitment of the heterotetrameric AP-1 complex.
In pull-down assay, Apm1 binds Apl2 even in the absence of Aps1 and Apl4, and Apl4 binds Aps1 even in the absence of Apm1 and Apl2. Consistently, the deletion of any subunit generally caused the disassociation of the heterotetrameric complex from endosomes, although some subunits weakly localized to endosomes. In addition, the deletion of individual subunits caused similar endosomal accumulation of v-SNARE synaptobrevin Syb1. Altogether, results suggest that the four subunits are all essential for the heterotetrameric complex formation and for the AP-1 function in exit transport from endosomes.
Summary: clathrin binding is retained as an ancillary annotation.
Reason: Retain the curator-mediated orthology transfer for clathrin association in the AP-1 context. The decisive target evidence establishes adaptor-complex assembly; it does not demonstrate that isolated sigma subunit is the principal direct clathrin-binding interface.
In pull-down assay, Apm1 binds Apl2 even in the absence of Aps1 and Apl4, and Apl4 binds Aps1 even in the absence of Apm1 and Apl2. Consistently, the deletion of any subunit generally caused the disassociation of the heterotetrameric complex from endosomes, although some subunits weakly localized to endosomes. In addition, the deletion of individual subunits caused similar endosomal accumulation of v-SNARE synaptobrevin Syb1. Altogether, results suggest that the four subunits are all essential for the heterotetrameric complex formation and for the AP-1 function in exit transport from endosomes.
Summary: clathrin-coated vesicle membrane is supported.
Reason: Fission yeast AP-1 subunit deletions alter recruitment to endosomes and trap Syb1 in the endosomal system. The Golgi/endosome-associated clathrin adaptor location is consistent with the conserved AP-1 coat function and the curated target-specific localization observations.
In pull-down assay, Apm1 binds Apl2 even in the absence of Aps1 and Apl4, and Apl4 binds Aps1 even in the absence of Apm1 and Apl2. Consistently, the deletion of any subunit generally caused the disassociation of the heterotetrameric complex from endosomes, although some subunits weakly localized to endosomes. In addition, the deletion of individual subunits caused similar endosomal accumulation of v-SNARE synaptobrevin Syb1. Altogether, results suggest that the four subunits are all essential for the heterotetrameric complex formation and for the AP-1 function in exit transport from endosomes.
Summary: clathrin-cargo adaptor activity is supported.
Reason: Aps1 contributes to the clathrin-cargo adaptor function of assembled AP-1, whose four subunits organize membrane cargo sorting. The contributes_to row captures this precisely; the broad domain mapping should also be interpreted in the obligate adaptor-complex context.
In pull-down assay, Apm1 binds Apl2 even in the absence of Aps1 and Apl4, and Apl4 binds Aps1 even in the absence of Apm1 and Apl2. Consistently, the deletion of any subunit generally caused the disassociation of the heterotetrameric complex from endosomes, although some subunits weakly localized to endosomes. In addition, the deletion of individual subunits caused similar endosomal accumulation of v-SNARE synaptobrevin Syb1. Altogether, results suggest that the four subunits are all essential for the heterotetrameric complex formation and for the AP-1 function in exit transport from endosomes.
We report that the gamma/sigma1 or alpha/sigma2 hemicomplexes bound the dileucine-based motifs of several proteins quite strongly, whereas binding by the beta1/mu1 and beta2/mu2 hemicomplexes, and the individual beta or mu subunits, was extremely weak or undetectable.
Summary: clathrin-cargo adaptor activity is supported.
Reason: Aps1 contributes to the clathrin-cargo adaptor function of assembled AP-1, whose four subunits organize membrane cargo sorting. The contributes_to row captures this precisely; the broad domain mapping should also be interpreted in the obligate adaptor-complex context.
In pull-down assay, Apm1 binds Apl2 even in the absence of Aps1 and Apl4, and Apl4 binds Aps1 even in the absence of Apm1 and Apl2. Consistently, the deletion of any subunit generally caused the disassociation of the heterotetrameric complex from endosomes, although some subunits weakly localized to endosomes. In addition, the deletion of individual subunits caused similar endosomal accumulation of v-SNARE synaptobrevin Syb1. Altogether, results suggest that the four subunits are all essential for the heterotetrameric complex formation and for the AP-1 function in exit transport from endosomes.
We report that the gamma/sigma1 or alpha/sigma2 hemicomplexes bound the dileucine-based motifs of several proteins quite strongly, whereas binding by the beta1/mu1 and beta2/mu2 hemicomplexes, and the individual beta or mu subunits, was extremely weak or undetectable.
GO:0042147 retrograde transport, endosome to Golgi
IDA PMID:19624755 Deletion mutants of AP-1 adaptin subunits display distinct p...
ACCEPT
Summary: retrograde transport, endosome to Golgi is supported.
Reason: The Aps1 sigma subunit is required for normal AP-1 complex formation and exit transport from endosomes; loss of individual subunits causes endosomal accumulation of Syb1. Retain the curated routes supported by the original target experiments and distinguish them from transport between cells.
In pull-down assay, Apm1 binds Apl2 even in the absence of Aps1 and Apl4, and Apl4 binds Aps1 even in the absence of Apm1 and Apl2. Consistently, the deletion of any subunit generally caused the disassociation of the heterotetrameric complex from endosomes, although some subunits weakly localized to endosomes. In addition, the deletion of individual subunits caused similar endosomal accumulation of v-SNARE synaptobrevin Syb1. Altogether, results suggest that the four subunits are all essential for the heterotetrameric complex formation and for the AP-1 function in exit transport from endosomes.
GO:0099638 endosome to plasma membrane protein transport
IDA PMID:19624755 Deletion mutants of AP-1 adaptin subunits display distinct p...
ACCEPT
Summary: endosome to plasma membrane protein transport is supported.
Reason: The Aps1 sigma subunit is required for normal AP-1 complex formation and exit transport from endosomes; loss of individual subunits causes endosomal accumulation of Syb1. Retain the curated routes supported by the original target experiments and distinguish them from transport between cells.
In pull-down assay, Apm1 binds Apl2 even in the absence of Aps1 and Apl4, and Apl4 binds Aps1 even in the absence of Apm1 and Apl2. Consistently, the deletion of any subunit generally caused the disassociation of the heterotetrameric complex from endosomes, although some subunits weakly localized to endosomes. In addition, the deletion of individual subunits caused similar endosomal accumulation of v-SNARE synaptobrevin Syb1. Altogether, results suggest that the four subunits are all essential for the heterotetrameric complex formation and for the AP-1 function in exit transport from endosomes.
Core Functions
Sigma subunit of AP-1 contributing to cargo sorting and vesicular exit transport from endosomes.
In pull-down assay, Apm1 binds Apl2 even in the absence of Aps1 and Apl4, and Apl4 binds Aps1 even in the absence of Apm1 and Apl2. Consistently, the deletion of any subunit generally caused the disassociation of the heterotetrameric complex from endosomes, although some subunits weakly localized to endosomes. In addition, the deletion of individual subunits caused similar endosomal accumulation of v-SNARE synaptobrevin Syb1. Altogether, results suggest that the four subunits are all essential for the heterotetrameric complex formation and for the AP-1 function in exit transport from endosomes.
We report that the gamma/sigma1 or alpha/sigma2 hemicomplexes bound the dileucine-based motifs of several proteins quite strongly, whereas binding by the beta1/mu1 and beta2/mu2 hemicomplexes, and the individual beta or mu subunits, was extremely weak or undetectable.
These computational predictions are reviewed separately from the GOA annotation set used for this review. The assessments below are from this project and do not constitute official GO annotations or endorsement by GO/UniProt. They are not included in the existing annotation review above.
Vas2/Aps1 supports AP-1-mediated membrane-protein sorting and exit transport from endosomes. Intracellular protein transport is supported but less precise than the established cargo-transport routes.
Review rationale: Fission yeast Aps1/Vas2 deletion and pull-down experiments establish AP-1 assembly and exit transport from endosomes, including trafficking of the membrane protein Syb1. GOA already records endosome-to-Golgi and endosome-to-plasma-membrane protein transport. The predicted intracellular protein transport is correct but less precise than those established routes. The unrelated ARBA intercellular-transport assertion means movement between cells and is not evidence supporting this assessment.
Supporting Evidence:
PMID:19624755: "In pull-down assay, Apm1 binds Apl2 even in the absence of Aps1 and Apl4, and Apl4 binds Aps1 even in the absence of Apm1 and Apl2. Consistently, the deletion of any subunit generally caused the disassociation of the heterotetrameric complex from endosomes, although some subunits weakly localized to endosomes. In addition, the deletion of individual subunits caused similar endosomal accumulation of v-SNARE synaptobrevin Syb1. Altogether, results suggest that the four subunits are all essential for the heterotetrameric complex formation and for the AP-1 function in exit transport from endosomes."