Coatomer subunit gamma-1 (COPG1)
The protein contains 874 amino acids for an estimated molecular weight of 97718 Da.
The coatomer is a cytosolic protein complex that binds to dilysine motifs and reversibly associates with Golgi non-clathrin-coated vesicles, which further mediate biosynthetic protein transport from the ER, via the Golgi up to the trans Golgi network. Coatomer complex is required for budding from Golgi membranes, and is essential for the retrograde Golgi-to-ER transport of dilysine-tagged proteins. In mammals, the coatomer can only be recruited by membranes associated to ADP-ribosylation factors (ARFs), which are small GTP-binding proteins; the complex also influences the Golgi structural integrity, as well as the processing, activity, and endocytic recycling of LDL receptors. Required for limiting lipid storage in lipid droplets. Involved in lipid homeostasis by regulating the presence of perilipin family members PLIN2 and PLIN3 at the lipid droplet surface and promoting the association of adipocyte triglyceride lipase (PNPLA2) with the lipid droplet surface to mediate lipolysis (By similarity). (updated: March 4, 2015)
Protein identification was indicated in the following studies:
- Goodman and co-workers. (2013) The proteomics and interactomics of human erythrocytes. Exp Biol Med (Maywood) 238(5), 509-518.
- Hegedűs and co-workers. (2015) Inconsistencies in the red blood cell membrane proteome analysis: generation of a database for research and diagnostic applications. Database (Oxford) 1-8.
- Bryk and co-workers. (2017) Quantitative Analysis of Human Red Blood Cell Proteome. J Proteome Res. 16(8), 2752-2761.
- Chu and co-workers. (2018) Quantitative mass spectrometry of human reticulocytes reveal proteome-wide modifications during maturation. Br J Haematol. 180(1), 118-133.
Methods
The following articles were analysed to gather the proteome content of erythrocytes.
The gene or protein list provided in the studies were processed using the ID mapping API of Uniprot in September 2018. The number of proteins identified and mapped without ambiguity in these studies is indicated below.
Only Swiss-Prot entries (reviewed) were considered for protein evidence assignation.
| Publication | Identification 1 | Uniprot mapping 2 | Not mapped / Obsolete | TrEMBL | Swiss-Prot |
|---|---|---|---|---|---|
| Goodman (2013) | 2289 (gene list) | 2278 | 53 | 20599 | 2269 |
| Lange (2014) | 1234 | 1234 | 7 | 28 | 1224 |
| Hegedus (2015) | 2638 | 2622 | 0 | 235 | 2387 |
| Wilson (2016) | 1658 | 1528 | 170 | 291 | 1068 |
| d'Alessandro (2017) | 1826 | 1817 | 2 | 0 | 1815 |
| Bryk (2017) | 2090 | 2060 | 10 | 108 | 1942 |
| Chu (2018) | 1853 | 1804 | 55 | 362 | 1387 |
1 as available in the article and/or in supplementary material
2 uniprot mapping returns all protein isoforms as one entry
The compilation of older studies can be retrieved from the Red Blood Cell Collection database.
The data and differentiation stages presented below come from the proteomic study and analysis performed by our partners of the GReX consortium, more details are available in their published work.
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| Variant | Description |
|---|---|
| dbSNP:rs15648 |
Biological Process
COPI coating of Golgi vesicle
Endoplasmic reticulum to Golgi vesicle-mediated transport
Establishment of Golgi localization
Intra-Golgi vesicle-mediated transport
Intracellular protein transport
Membrane organization
Organelle transport along microtubule
Protein secretion
Retrograde vesicle-mediated transport, Golgi to endoplasmic reticulum
The reference OMIM entry for this protein is 615525
Coatomer protein complex, subunit gamma-1; copg1
Cop, gamma-1
DESCRIPTION
Intracellular cargo transport is mediated by vesicles decorated with protein complexes, such as coat protein complex I (COPI; see 601924). COPI consists of a 7-subunit coatomer subcomplex plus the small G protein ARF1 (103180). COPG1 and COPG2 (604355) are paralogous isoforms of the gamma subunit of the coatomer subcomplex (Moelleken et al., 2007).CLONING
By EST database analysis, followed by PCR of a human liver cDNA library, Futatsumori et al. (2000) cloned COPG1, which they called gamma-1 COP. The deduced protein contains 874 amino acids and shares about 80% identity with human gamma-2 COP. In transfected rat hepatocytes, epitope-tagged human gamma-1 COP colocalized with beta-COP (COPB; 600959) in the paranuclear region, characteristic of Golgi localization. Hahn et al. (2000) cloned mouse Copg1. The deduced 874-amino acid mouse protein shares 97% identity with human COPG1. Northern blot analysis detected variable expression of 3 Copg1 transcripts in all mouse tissues examined, with highest expression of all 3 transcripts in testis.GENE FUNCTION
Using yeast 2-hybrid analysis, Futatsumori et al. (2000) showed that both human gamma-1 and gamma-2 COP interacted directly with both human zeta-1 (COPZ1; 615472) and zeta-2 COP (COPZ2; 615526). None of the gamma or zeta subunits interacted with other COP subunits or with subunits of the AP1 clathrin adaptor complex (see 603531). Both gamma subunits also bound to the cytoplasmic domain of p23 (TMP21; 605406), a putative receptor for cargo proteins transported between the endoplasmic reticulum and Golgi complex. Futatsumori et al. (2000) concluded that gamma-1 and gamma-2 COP may be functionally redundant. By immunoprecipitation and immunoelectron microscopy of mouse and rat cells, Moelleken et al. (2007) found a preference for Copg1/Copz1- and Copg1/Copz2-containing coatomer complexes in the early Golgi apparatus and Copg2/Copz1-containing coatomer complexes in the late Golgi apparatus. They concluded that different coatomer isoforms may serve different intracellular transport routes.MAPPING
Hartz (2013) mapped the COPG1 gene to chromosome 3q21.3 based on an alignment of the COPG1 sequence (GenBank GENBANK AB047846) with the genomic sequence (GRCh37). ... More on the omim web site
Feb. 2, 2018: Protein entry updated
Automatic update: Uniprot description updated
Dec. 19, 2017: Protein entry updated
Automatic update: Uniprot description updated
Nov. 23, 2017: Protein entry updated
Automatic update: Uniprot description updated
March 16, 2016: Protein entry updated
Automatic update: OMIM entry 615525 was added.
Feb. 24, 2016: Protein entry updated
Automatic update: model status changed