Proteasome activator complex subunit 2 (PSME2)
The protein contains 239 amino acids for an estimated molecular weight of 27402 Da.
Implicated in immunoproteasome assembly and required for efficient antigen processing. The PA28 activator complex enhances the generation of class I binding peptides by altering the cleavage pattern of the proteasome. (updated: April 1, 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.
- 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 |
|---|---|
| dbSNP:rs7146672 |
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
Interleukin-12-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
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
Positive regulation of endopeptidase activity
Post-translational protein modification
Pre-replicative complex assembly
Proteasome-mediated ubiquitin-dependent protein catabolic process
Protein deubiquitination
Protein polyubiquitination
Regulation of apoptotic process
Regulation of cellular amino acid metabolic process
Regulation of G1/S transition of mitotic cell cycle
Regulation of hematopoietic stem cell differentiation
Regulation of mitotic cell cycle phase transition
Regulation of mRNA stability
Regulation of proteasomal protein catabolic process
Regulation of transcription from RNA polymerase II promoter in response to hypoxia
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
Viral process
Wnt signaling pathway, planar cell polarity pathway
The reference OMIM entry for this protein is 602161
Proteasome activator subunit 2; psme2
Proteasome activator 28-beta
Pa28-beta; pa28b
Mcp activator, 31-kd subunit
DESCRIPTION
The PA28 complex is an alternative proteasome activator that does not employ the use of ubiquitin. The complex is composed of 2 homologous subunits, PA28-alpha (PSME1; 600654) and PA28-beta (PSME2; 602161), which form a hexameric ring. The PA28 complex is expressed constitutively in antigen-presenting cells. Its expression is upregulated by gamma-interferon (147570), and it appears to be involved in the presentation of endogenous antigens by MHC class I molecules (summary by McCusker et al., 1999).CLONING
Ahn et al. (1995) reported the sequence of the human PA28-beta (PSME2) gene and those of rat Pa28-alpha and -beta. The deduced 239-amino acid human PA28-beta protein has a calculated molecular mass of 27.1 kD. It shares 89% amino acid identity with rat Pa28-beta.GENE STRUCTURE
McCusker et al. (1999) sequenced the PSME1 and PSME2 genes. Both genes contain 11 exons, consistent with gene duplication during vertebrate evolution. The intron/exon organization of the genes is highly conserved, the major difference being the absence of the exon encoding the lysine and glutamic acid-rich KEKE motif in the gene product of the PSME2 gene.MAPPING
By fluorescence in situ hybridization, McCusker et al. (1997) showed that the PSME1 and PSME2 genes lie within 30 to 40 kb of each other on chromosome 14q11.2.GENE FUNCTION
In vitro, PA28 binds and activates proteasomes. Preckel et al. (1999) demonstrated that mice with a disrupted Pa28b gene lack Pa28a (Psme1) and Pa28b polypeptides, demonstrating that Pa28 functions as a heterooligomer in vivo. Processing of antigenic epitopes derived from exogenous or endogenous antigens is altered in Pa28 -/- mice. Cytotoxic T-lymphocyte responses are impaired and assembly of immunoproteasomes is greatly inhibited in mice lacking Pa28. These results showed that PA28 is necessary for immunoproteasome assembly and is required for efficient antigen processing, thus demonstrating the importance of PA28-mediated proteasome function in immune responses. ... 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 602161 was added.