Anti-PSMB4 Antibody Picoband®

Proteasome subunit beta type-4 also known as 20S proteasome subunit beta-7 (based on systematic nomenclature) is a protein that in humans is encoded by the PSMB4 gene. The proteasome is a multicatalytic proteinase complex with a highly ordered ring-shaped 20S core structure. The core structure is composed of 4 rings of 28 non-identical subunits; 2 rings are composed of 7 alpha subunits and 2 rings are composed of 7 beta subunits. Proteasomes are distributed throughout eukaryotic cells at a high concentration and cleave peptides in an ATP/ubiquitin-dependent process in a non-lysosomal pathway. An essential function of a modified proteasome, the immunoproteasome, is the processing of class I MHC peptides. This gene encodes a member of the proteasome B-type family, also known as the T1B family, that is a 20S core beta subunit.

Protease that deconjugates SUMO1, SUMO2 and SUMO3 from targeted proteins. Processes preferentially poly-SUMO2 and poly-SUMO3 chains, but does not efficiently process SUMO1, SUMO2 and SUMO3 precursors. Deconjugates SUMO1 from RXRA, leading to transcriptional activation. Involved in chromosome alignment and spindle assembly, by regulating the kinetochore CENPH-CENPI-CENPK complex. Desumoylates PML and CENPI, protecting them from degradation by the ubiquitin ligase RNF4, which targets polysumoylated proteins for proteasomal degradation. Desumoylates also RPA1, thus preventing recruitment of RAD51 to the DNA damage foci to initiate DNA repair through homologous recombination.

1. Brehm, A., Liu, Y., Sheikh, A., Marrero, B., Omoyinmi, E., Zhou, Q., Montealegre, G., Biancotto, A., Reinhardt, A., Almeida de Jesus, A., Pelletier, M., Tsai, W. L., and 31 others. Additive loss-of-function proteasome subunit mutations in CANDLE/PRAAS patients promote type I IFN production. J. Clin. Invest. 125: 4196-4211, 2015. Note: Erratum: J. Clin. Invest. 126: 795 only, 2016. 2. Gerards, W. L. H., Hop, F. W. H., Hendriks, I. L. A. M., Bloemendal, H. Cloning and expression of a human pro (tea) some beta-subunit cDNA: a homologue of the yeast PRE4-subunit essential for peptidylglutamyl-peptide hydrolase activity. FEBS Lett. 346: 151-155, 1994. 3. Liu, Y., Ramot, Y., Torrelo, A., Paller, A. S., Si, N., Babay, S., Kim, P. W., Sheikh, A., Lee, C.-C. R., Chen, Y., Vera, A., Zhang, X., Goldbach-Mansky, R., Zlotogorski, A. Mutations in proteasome subunit beta type 8 cause chronic atypical neutrophilic dermatosis with lipodystrophy and elevated temperature with evidence of genetic and phenotypic heterogeneity. Arthritis Rheum. 64: 895-907, 2012.

At -20°C for one year from date of receipt. After reconstitution, at 4°C for one month. It can also be aliquotted and stored frozen at -20°C for six months. Avoid repeated freezing and thawing.