Tumor Protein p53 Regulated Apoptosis Inducing Protein 1 (TP53AIP1)

The p53AIP1 gene has 3 major transcripts, designated alpha, beta, and gamma, which encode proteins of 124, 86, and 108 amino acids, respectively.The gene spans an 8.2-kb genomic region and contains 5 exons. The 3 transcripts are generated by alternative splicing; exon 2 of p53AIP1-gamma includes introns 2 and 3 of p53AIP1-alpha. Northern blot analysis of 16 normal tissues detected p53AIP1 expression only in thymus. Substitution of ser46 inhibited the ability of p53 to induce apoptosis and selectively blocked expression of p53AIP1. These results suggested that p53AIP1 is likely to play an important role in mediating p53-dependent apoptosis, and phosphorylation of ser46 on p53 regulates the transcriptional activation of this apoptosis-inducing gene.