Proteasome subunit alpha type-2 (PSMA2)
The protein contains 234 amino acids for an estimated molecular weight of 25899 Da.
Component of the 20S core proteasome complex involved in the proteolytic degradation of most intracellular proteins. This complex plays numerous essential roles within the cell by associating with different regulatory particles. Associated with two 19S regulatory particles, forms the 26S proteasome and thus participates in the ATP-dependent degradation of ubiquitinated proteins. The 26S proteasome plays a key role in the maintenance of protein homeostasis by removing misfolded or damaged proteins that could impair cellular functions, and by removing proteins whose functions are no longer required. Associated with the PA200 or PA28, the 20S proteasome mediates ubiquitin-independent protein degradation. This type of proteolysis is required in several pathways including spermatogenesis (20S-PA200 complex) or generation of a subset of MHC class I-presented antigenic peptides (20S-PA28 complex). (updated: Jan. 31, 2018)
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.
- 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.
- Wilson and co-workers. (2016) Comparison of the Proteome of Adult and Cord Erythroid Cells, and Changes in the Proteome Following Reticulocyte Maturation. Mol Cell Proteomics. 15(6), 1938-1946.
- Bryk and co-workers. (2017) Quantitative Analysis of Human Red Blood Cell Proteome. J Proteome Res. 16(8), 2752-2761.
- D'Alessandro and co-workers. (2017) Red blood cell proteomics update: is there more to discover? Blood Transfus. 15(2), 182-187.
- 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 |
|---|---|
| a colorectal cancer sample; somatic mutation |
Biological Process
Anaphase-promoting complex-dependent catabolic process
Antigen processing and presentation of exogenous peptide antigen via MHC class I
Antigen processing and presentation of exogenous peptide antigen via MHC class I, TAP-dependent
Antigen processing and presentation of peptide antigen via MHC class I
Apoptotic process
Cellular nitrogen compound metabolic process
DNA damage response, signal transduction by p53 class mediator resulting in cell cycle arrest
Fc-epsilon receptor signaling pathway
G1/S transition of mitotic cell cycle
Gene expression
Interleukin-1-mediated signaling pathway
MAPK cascade
Mitotic cell cycle
Negative regulation of apoptotic process
Negative regulation of canonical Wnt signaling pathway
Negative regulation of G2/M transition of mitotic cell cycle
Neutrophil degranulation
NIK/NF-kappaB signaling
Obsolete negative regulation of ubiquitin-protein ligase activity involved in mitotic cell cycle
Obsolete positive regulation of ubiquitin-protein ligase activity involved in regulation of mitotic cell cycle transition
Obsolete regulation of ubiquitin-protein ligase activity involved in mitotic cell cycle
Positive regulation of canonical Wnt signaling pathway
Post-translational protein modification
Pre-replicative complex assembly
Proteasomal protein catabolic process
Proteasomal ubiquitin-independent protein catabolic process
Proteasome-mediated ubiquitin-dependent protein catabolic process
Protein deubiquitination
Protein polyubiquitination
Regulation of apoptotic process
Regulation of cellular amino acid metabolic process
Regulation of hematopoietic stem cell differentiation
Regulation of mitotic cell cycle phase transition
Regulation of mRNA stability
Regulation of transcription from RNA polymerase II promoter in response to hypoxia
Response to virus
SCF-dependent proteasomal ubiquitin-dependent protein catabolic process
Small molecule metabolic process
Stimulatory C-type lectin receptor signaling pathway
T cell receptor signaling pathway
Transmembrane transport
Tumor necrosis factor-mediated signaling pathway
Ubiquitin-dependent protein catabolic process
Viral process
Wnt signaling pathway, planar cell polarity pathway
The reference OMIM entry for this protein is 176842
Proteasome subunit, alpha-type, 2; psma2
Hc3
Psc2
CLONING
Proteasomes (multicatalytic proteinase complexes) are symmetric, ring-shaped or cylindrical cytoplasmic particles with the unusually large size of 20S (Mr approximately 750,000). They are composed of polysubunits of similar sizes (Mr 21,000-32,000) but different charges. They are ubiquitously distributed in eukaryotic cells at considerably high concentrations, suggesting their general importance in cellular functions. Proteasomes have been demonstrated to catalyze an energy-dependent degradative process in a nonlysosomal pathway (summary by Tamura et al., 1991). Tamura et al. (1991) reported molecular cloning and sequencing of full-length cDNAs for 5 subunits of proteasomes which they symbolized HC2 (602854), HC3, HC5 (602017), HC8 (176843), and HC9 (PSMA4; 176846). The proteasomes of human liver were studied with description of their structure and homology with the subunits of proteasomes from other species. The 5 subunits had 263, 234, 241, 255, and 261 amino acid residues and calculated molecular weights of 29,554, 25,897, 26,847, 28,431, and 29,482, respectively. They were encoded by single independent genes. Most of the genes for proteasome components are highly homologous and their proteins show approximately 30% identity in amino acid sequence. The exception is component 5 (PSMA5; 176844), which may have diverged in eukaryotes during evolution.GENE STRUCTURE
Tamura et al. (1994) isolated 2 human proteasome genes encoding the alpha-type HC3 and the beta-type HC5 subunits. Analysis of their promoter sequences revealed the absence of TATA and CAAT elements and the existence of 2 or 3 GC boxes that function coordinately as promoters of the 2 genes. Differences in the exon/intron organizations of these genes, however, suggested that they diverged at an early stage of evolution.MAPPING
Okumura et al. (1995) mapped the PSMA2 gene to chromosome 6q27 by fluorescence in situ hybridization. ... More on the omim web site
Feb. 10, 2018: Protein entry updated
Automatic update: Entry updated from uniprot information.
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 176842 was added.