Coatomer subunit beta' (COPB2)
The protein contains 906 amino acids for an estimated molecular weight of 102487 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 (By similarity).', 'This coatomer complex protein, essential for Golgi budding and vesicular trafficking, is a selective binding protein (RACK) for protein kinase C, epsilon type. It binds to Golgi membranes in a GTP-dependent manner (By similarity). (updated: Oct. 10, 2018)
Protein identification was indicated in the following studies:
- 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 |
|---|---|
| MCPH19 |
Biological Process
Endoplasmic reticulum to Golgi vesicle-mediated transport
Intra-Golgi vesicle-mediated transport
Intracellular protein transport
Retrograde vesicle-mediated transport, Golgi to endoplasmic reticulum
Toxin transport
Cellular Component
COPI vesicle coat
Cytosol
Endoplasmic reticulum membrane
Golgi membrane
Transport vesicle
The reference OMIM entry for this protein is 606990
Coatomer protein complex, subunit beta-2; copb2
Beta-2 coat protein
Beta-prime cop
DESCRIPTION
The Golgi coatomer complex (see 601924) constitutes the coat of nonclathrin-coated vesicles and is essential for Golgi budding and vesicular trafficking. It consists of 7 protein subunits, including COPB2.CLONING
Using monoclonal antibodies cross-reactive with mouse Tcp1 (186980), Harrison Lavoie et al. (1993) detected a 102-kD Golgi-associated protein by Western blot analysis and immunofluorescence microscopy. By screening human cDNA expression libraries, they isolated a cDNA encoding p102, or COPB2. The deduced 906-amino acid protein contains 6 N-terminal WD40 repeats and a leu-asp-asp (LDD) motif at the C terminus, like mouse Tcp1. Biochemical fractionation, immunoprecipitation, and Western blot analyses showed that COPB2 is a component of a 500- to 600-kD coatomer protein complex that includes COPB (600959). Immunofluorescence microscopy demonstrated that COPB and COPB2 disperse from Golgi membranes in the presence of brefeldin A. Harrison-Lavoie et al. (1993) suggested that COPB2 may be involved in regulating membrane traffic in the constitutive exocytic pathway. Csukai et al. (1997) used the V1 region of protein kinase C-epsilon (PRKCE; 176975) to clone a PRKCE-selective RACK (see RACK1; 176981), which they identified as Copb2, from rat. The predicted rat protein contains 7 WD40 motifs. Immunofluorescence microscopy and immunoprecipitation analysis demonstrated colocalization of Copb2 with activated PRKCE in cardiac myocytes and that PRKCE binds to Golgi membranes in a Copb2-dependent manner.MAPPING
Using FISH, De Baere et al. (1998) mapped the COPB2 gene to chromosome 3q23. ... More on the omim web site
June 30, 2020: Protein entry updated
Automatic update: OMIM entry 606990 was added.
Oct. 19, 2018: Additional information
Initial protein addition to the database. This entry was referenced in Bryk and co-workers. (2017).