Alternative titles; symbols
HGNC Approved Gene Symbol: PSME4
Cytogenetic location: 2p16.2 Genomic coordinates (GRCh38) : 2:53,864,069-53,970,993 (from NCBI)
By sequencing clones obtained from a size-fractionated myeloid cell line cDNA library, Nomura et al. (1994) cloned a partial PSME4 cDNA, which they designated KIAA0077. Northern blot analysis detected ubiquitous expression, with highest expression in skeletal muscle and testis, and lowest expression in colon and peripheral blood leukocytes.
Ustrell et al. (2002) cloned full-length mouse and human PSME4, which they designated PA200. The deduced 1,843-amino acid proteins share over 90% sequence identity. PA200 contains a bipartite nuclear targeting sequence and several potential phosphorylation sites, many of which are sites for the DNA repair kinases ATM (607585) and PRKDC (600899). Two-dimensional gel electrophoresis of bovine testis PA200 resolved the 200-kD band into several isoelectric variants that were unaffected by phosphatase treatment. Western blot analysis of mouse tissues detected 3 species: a 200-kD species that was most abundant in testis; a 60-kD species that was most prominent in brain but also abundant in liver and lung; and a 160-kD species that was abundant in other organs.
Ustrell et al. (2002) found that PA200 purified from bovine testis activated proteasomal hydrolysis of peptides, but not proteins. It particularly activated the peptidylglutamyl peptidase activity, and activation was ATP-independent. Proteasome activation was also accompanied by the formation of a PA200-proteasome complex in HeLa cells. Following gamma irradiation, but not UV irradiation or peroxide treatment, the uniform nuclear distribution of endogenous PA200 in HeLa cells reorganized into punctate nuclear foci. Ustrell et al. (2002) hypothesized that PA200 is involved in DNA repair by recruiting proteasomes to double-strand breaks.
By analysis of a panel of human/rodent hybrid cell lines, Nomura et al. (1994) mapped the PSME4 gene to chromosome 2.
Nomura, N., Nagase, T., Miyajima, N., Sazuka, T., Tanaka, A., Sato, S., Seki, N., Kawarabayasi, Y., Ishikawa, K., Tabata, S. Prediction of the coding sequences of unidentified human genes. II. The coding sequences of 40 new genes (KIAA0041-KIAA0080) deduced by analysis of cDNA clones from human cell line KG-1. DNA Res. 1: 223-229, 1994. [PubMed: 7584044] [Full Text: https://doi.org/10.1093/dnares/1.5.223]
Ustrell, V., Hoffman, L., Pratt, G., Rechsteiner, M. PA200, a nuclear proteasome activator involved in DNA repair. EMBO J. 21: 3516-3525, 2002. [PubMed: 12093752] [Full Text: https://doi.org/10.1093/emboj/cdf333]