Proteasome assembly chaperone 2 (PSMG2)
The protein contains 264 amino acids for an estimated molecular weight of 29396 Da.
Chaperone protein which promotes assembly of the 20S proteasome as part of a heterodimer with PSMG1. The PSMG1-PSMG2 heterodimer binds to the PSMA5 and PSMA7 proteasome subunits, promotes assembly of the proteasome alpha subunits into the heteroheptameric alpha ring and prevents alpha ring dimerization. (updated: March 4, 2015)
Protein identification was indicated in the following studies:
- Lange and co-workers. (2014) Annotating N termini for the human proteome project: N termini and Nα-acetylation status differentiate stable cleaved protein species from degradation remnants in the human erythrocyte proteome. J Proteome Res. 13(4), 2028-2044.
- 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.
- D'Alessandro and co-workers. (2017) Red blood cell proteomics update: is there more to discover? Blood Transfus. 15(2), 182-187.
- Bryk and co-workers. (2017) Quantitative Analysis of Human Red Blood Cell Proteome. J Proteome Res. 16(8), 2752-2761.
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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The reference OMIM entry for this protein is 609702
Proteasome-assembling chaperone 2; psmg2
Proteasome assembly chaperone 2; pac2
Tnfsf5-induced protein 1; tnfsf5ip1
Hepatocellular carcinoma-associated protein 3; hcca3
Cd40 ligand-activated specific transcript 3; clast3
CLONING
By differential display PCR to identify genes upregulated in hepatocellular carcinoma, followed by screening a placenta cDNA library, Wang et al. (2001) cloned TNFSF5IP1, which they called HCCA3. The deduced 264-amino acid protein contains 2 N-glycosylation sites, 3 N-myristoylation sites, and several phosphorylation sites. Northern blot analysis detected a 1.7-kb HCCA3 transcript in all tissues examined. Expression was high in lung, brain, and colon, moderate in muscle, stomach, spleen, and heart, and weak in small intestine, pancreas, and liver. Elevated HCCA3 expression in hepatocellular carcinoma was associated with tumor invasiveness and metastasis, but not with tumor size, degree of differentiation, or other parameters. Using immunofluorescence, Bahar et al. (2002) found that mouse Clast3 localized in nuclear dot-like foci in transfected mouse fibroblasts.GENE FUNCTION
Bahar et al. (2002) found that CLAST3 expression increased in human and mouse B cells upon activation. In synchronized mouse fibroblasts, Clast3 expression was low in G1-arrested cells and increased during S and G2-M phases. Overexpression of Clast3 resulted in growth retardation, polyploidy, and generation of multinucleated cells. Treatment of Clast3 transfectants with nocodazole, a spindle-damaging agent, enhanced the incidence of multinucleated cells, suggesting that Clast3 impairs the same checkpoint activated by nocodazole. Downregulation of Clast3 expression by antisense oligonucleotides decreased the number of cells at G2-M phase and concomitantly increased the number of apoptotic cells. Hirano et al. (2005) reported 2 chaperones designated proteasome-assembling chaperone-1 (PAC1; 605296) and PAC2, that are involved in the maturation of the mammalian 20S proteasomes. PAC1 and PAC2 associate as heterodimers with proteasome precursors and are degraded after formation of the 20S proteasome is completed. Overexpression of PAC1 or PAC2 accelerates the formation of precursor proteasomes, whereas knockdown by short interfering RNA impairs it, resulting in poor maturation of 20S proteasomes. Furthermore, Hirano et al. (2005) showed that the PAC complex provides a scaffold for alpha ring formation and keeps the alpha rings competent for the subsequent formation of half-proteasomes. Thus, Hirano et al. (2005) concluded that their results identify a mechanism for the correct assembly of 20S proteasomes.MAPPING
The International Radiation Hybrid Mapping Consortium mapped the TNFSF5IP1 gene to chromosome 18 (TMAP A006T17). ... 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 609702 was added.