Protein Phosphatase 1, Regulatory Subunit 13 Like Protein (PPP1R13L)

IASPP is one of the most evolutionarily conserved inhibitors of p53 (TP53), whereas ASPP1 and ASPP2 are activators of p53. The deduced 351-amino acid partial protein has a calculated molecular mass of 40 kD. RAI contains 4 consecutive ankyrin repeats and a C-terminal SH3 domain. The C-terminal 223 amino acids share 52% sequence identity with the C terminus of 53BP2, a p53-binding protein. Northern blot analysis detected transcripts of 3.4 and 6 kb. Expression of RAI was high in heart, placenta, and prostate, and was reduced in brain, liver, skeletal muscle, testis, and peripheral blood leukocytes. Fluorescence-tagged RAI transfected into HeLa cells showed a nuclear subcellular distribution, as did RELA.The deduced 824-amino acid has predicted molecular mass of 98 kD that was confirmed by Western blot analysis.