GOLGA8K (Golgin subfamily A member 8K) is a poorly characterized member of the GOLGA8/CASP-related golgin subfamily. Like other golgins, it contains extensive coiled-coil domains that are predicted to form elongated structures projecting from the Golgi membrane. Based on conserved domain architecture and phylogenetic inference from characterized golgin family members, GOLGA8K is predicted to localize to the cis-Golgi compartment where it likely functions as a vesicle tether or scaffold involved in Golgi organization. The gene resides within the 15q11-q13 region, where GOLGA8 core duplicons are known to mediate recurrent chromosomal rearrangements associated with Prader-Willi and Angelman syndromes. Direct experimental characterization of GOLGA8K specifically is lacking; all functional inferences derive from domain conservation and family-level evidence.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0000137 Golgi cis cisterna | IBA GO_REF:0000033 | ACCEPT | Summary: IBA annotation for cis-Golgi localization inferred from phylogenetic analysis using PANTHER. Supporting evidence from orthologs includes FB:FBgn0034697 (Drosophila), RGD:620282 (rat), and UniProtKB:Q08379 (human golgin-84/CASP). Golgin-84/CASP (Q08379) is a well-characterized cis-Golgi tether that interacts with other golgins during intra-Golgi trafficking. The annotation is consistent with GOLGA8K domain architecture containing GOLGA domains (IPR024858, IPR043937) and the conserved coiled-coil structure typical of Golgi-localized golgins. Reason: The IBA annotation is well-supported by phylogenetic inference. GOLGA8K shares conserved domain architecture with characterized cis-Golgi golgins including golgin-84/CASP. Deep research confirms that golgins occupy the cytoplasmic face of the Golgi and function as tethers/scaffolds, with cis-Golgi localization being consistent with the GOLGA8/CASP subfamily. The coiled-coil regions and GOLGA domains in GOLGA8K strongly support Golgi cisterna localization. Supporting Evidence: GO_REF:0000033 Phylogenetic inference from orthologs FB:FBgn0034697, RGD:620282, UniProtKB:Q08379 |
| GO:0005801 cis-Golgi network | IBA GO_REF:0000033 | ACCEPT | Summary: IBA annotation for cis-Golgi network localization based on phylogenetic inference. The annotation derives from orthologs including MGI:MGI:2139395 (mouse), RGD:620282 (rat), and UniProtKB:Q08379 (human golgin-84/CASP). The cis-Golgi network is the entry point for ER-derived vesicles, and golgins in this region function as vesicle tethers. Deep research indicates golgins "occupy the cytoplasmic face of the Golgi, functioning as tethers/scaffolds in ER-to-Golgi and intra-Golgi trafficking." Reason: The cis-Golgi network annotation is phylogenetically well-supported and consistent with the GOLGA8/CASP subfamily function. Family-level evidence demonstrates that golgins with GOLGA domains localize to cis-Golgi compartments where they participate in vesicle capture. This annotation complements the Golgi cis cisterna annotation and represents an appropriate level of specificity for a golgin family member. Supporting Evidence: GO_REF:0000033 Phylogenetic inference from orthologs MGI:MGI:2139395, RGD:620282, UniProtKB:Q08379 |
| GO:0007030 Golgi organization | IBA GO_REF:0000033 | ACCEPT | Summary: IBA annotation for biological process involvement in Golgi organization. Phylogenetic inference from orthologs FB:FBgn0034697, RGD:620282, and UniProtKB:Q08379. Golgins are established as major structural components of the Golgi matrix. Deep research notes that golgins are "Golgi-matrix tethers that project into the cytoplasm and mediate vesicle capture, Golgi structural integrity, and trafficking." Super-resolution studies describe organized arrangements of golgins at the Golgi rim contributing to architecture. Reason: The annotation to Golgi organization is strongly supported by family-level evidence. Golgins are well-established as structural scaffolds that maintain Golgi integrity. The coiled-coil architecture of GOLGA8K is consistent with the extended tether function that golgins use to organize Golgi structure. This represents a core function for golgin family members and is appropriate for GOLGA8K based on phylogenetic conservation. Supporting Evidence: GO_REF:0000033 Phylogenetic inference from orthologs FB:FBgn0034697, RGD:620282, UniProtKB:Q08379 |
| GO:0032580 Golgi cisterna membrane | IBA GO_REF:0000033 | ACCEPT | Summary: IBA annotation for Golgi cisterna membrane localization from phylogenetic analysis with PANTHER:PTN000094136 and orthologs including RGD:620282. Golgins are known to be membrane-associated through their C-termini while projecting coiled-coil domains into the cytoplasm. Deep research confirms that golgins are "C-terminus anchored to Golgi membrane or via adaptors" with "long cytosolic extensions projecting from Golgi surface." Reason: The Golgi cisterna membrane annotation is consistent with golgin biology. GOLGA8K contains the GOLGA_C domain (IPR043937) which is associated with C-terminal membrane anchoring in golgins. The annotation appropriately captures the membrane-associated nature of golgins while the other cellular component annotations capture the specific sub-Golgi localization. Supporting Evidence: GO_REF:0000033 Phylogenetic inference from PANTHER:PTN000094136, RGD:620282 |
| GO:0005794 Golgi apparatus | IEA GO_REF:0000002 | ACCEPT | Summary: IEA annotation from InterPro domain mapping (InterPro:IPR024858 GOLGA, InterPro:IPR043937 GOLGA_C). These domains are characteristic of golgins, which by definition localize to the Golgi apparatus. The annotation is broader than the IBA annotations for cis-Golgi network and Golgi cis cisterna, which provide more specific localization. Reason: The Golgi apparatus annotation is accurate based on the presence of GOLGA-family domains. While it is less specific than the IBA annotations for cis-Golgi localization, it is not incorrect. IEA annotations from InterPro mappings are generally reliable for cellular component when based on well-characterized domain families. The GOLGA domains have strong predictive value for Golgi localization. Supporting Evidence: GO_REF:0000002 InterPro domain mapping from IPR024858 (GOLGA) and IPR043937 (GOLGA_C) |
| GO:0005801 cis-Golgi network | IEA GO_REF:0000002 | ACCEPT | Summary: IEA annotation for cis-Golgi network from InterPro domain mapping (InterPro:IPR043937 GOLGA_C). This is the same term as the IBA annotation above, but derived through a different evidence pathway (InterPro domain mapping vs phylogenetic inference). The GOLGA_C domain is associated with cis-Golgi localization in golgin family members. Reason: This annotation is a duplicate of the IBA annotation for the same GO term (GO:0005801) but with different evidence. Both IEA (from domain mapping) and IBA (from phylogeny) support cis-Golgi network localization. The redundancy is acceptable in GO as different evidence types can independently support the same annotation. The InterPro-based inference is consistent with the phylogenetic inference. Supporting Evidence: GO_REF:0000002 InterPro domain mapping from IPR043937 (GOLGA_C) |
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Download this section (compressed HTML)Q: Does GOLGA8K have functional redundancy with other GOLGA8 family paralogs, or does it have a distinct role in Golgi organization? The GOLGA8 family has expanded through segmental duplications in the human genome.
Q: What is the expression pattern and tissue-specific function of GOLGA8K, given its reported enrichment in testis (per HPA data)?
Experiment: Immunofluorescence microscopy with GOLGA8K-specific antibodies to confirm sub-Golgi localization and compare to other golgin family members.
Experiment: CRISPR knockout or knockdown of GOLGA8K to assess effects on Golgi morphology and secretory pathway function.
Experiment: Proximity labeling (BioID/APEX) to identify GOLGA8K-interacting proteins and determine its position in the golgin interaction network.
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