PPP1R13B polyclonal antibody

ASPP proteins interact with p53 and are responsible for enhancing p53-induced apoptosis but not cell cycle arrest. Inhibition of endogenous ASPP1 (PPP1R13B) function inhibits the apoptotic function of endogenous p53 in response to apoptotic stimuli. ASPP1 amplifies DNA binding and transactivation function of p53 on the promoters of proapoptotic genes in vivo. Expres-sion of ASPP1 is often downregulated in human breast carcinomas expressing wildtype p53, but not in those expressing mutant p53. This research indicates that ASPP1 regulates the tumor suppression function of p53 in vivo. ASPP1 is predominantly a cytoplasmic protein, although some fraction of the polypeptide is nuclear. Defects in PPP1R13B, the gene which encodes ASPP1, may be a cause of breast cancers. The deduced ASPP1 protein contains 1,090 amino acid residues.