Anti-B23 antibody, Mouse monoclonal
clone FC82291, purified from hybridoma cell culture
Anti-NPM, Anti-Nucleophosmin
B23 (also known as NPM, nucleophosmin, numatrin or NO38) is a phosphoprotein, widely expressed in all cell types, and localized in granular regions of the nucleolus associated with pre-ribosomal particles. This protein was found to be involved in several nuclear functions such as assembly and/or intranuclear transport of preribosomal particles, cytoplasmic/nuclear trafficking, regulation of DNA polymerase A activity and centrosome duplication. Phosphorylation of B23 is mediated by a cyclin complex, CDK2/cyclin E.
Phosphorylation causes the dissociation of B23 from the centrosome and enables the duplication of the centrosome during cell mitosis. B23 was also found to be involved in pro-myelocytic leukemia in which the gene for B23 fuses with retinoic acid receptor a (RARa). As a consequence, a fusion protein (60-7 0 kDa) is produced containing parts of the two genes.