Tumor Protein p53 Inducible Nuclear Protein 1 (TP53INP1)

Alternative splicing generates 2 P53DINP1 transcripts, P53DINP1a and P53DINP1b, which encode 240- and 164-amino acid proteins, respectively. Northern blot analysis detected a 6-kb P53DINP1 transcript in all tissues tested, with relatively higher expression in pancreas, spleen, testis, and peripheral leukocyte.Overexpression of P53DINP1 and DNA damage by DSBs synergistically enhanced ser46 phosphorylation of p53, induction of P53AIP1 expression, and apoptotic cell death. Furthermore, the protein complex interacting with P53DINP1 was found to phosphorylate ser46 of p53. These results suggested that P53DINP1 may regulate p53-dependent apoptosis through phosphorylation of p53 at ser46, serving as a cofactor for the putative p53-ser46 kinase.