TP53 Regulating Kinase (TP53RK)

The deduced 253-amino acid has a nuclear localization signal and characteristics of a protein kinase, but it lacks some typical protein kinase motifs. PRPK shares 83% amino acid identity with the 244-amino acid mouse protein, with most differences in 9 N-terminal amino acids. Northern blot analysis detected an abundant transcript of about 1.0 kb in testis. Lower expression was found in heart, kidney, and spleen, and no expression was found in the other tissues examined. RT-PCR detected expression in human adherent cancer cell lines of epithelial origin, but not in B-cell lymphoid tumor cell lines. Western blot analysis detected endogenous PRPK in embryonic kidney cells, activated T cells, and a T-cell lymphoma cell line. The apparent molecular mass was 31 kD. Epitope-tagged PRPK localized to the nucleus of transfected COS-7 cells.