Aberrant expression and function of p53 in T-cells immortalized by HTLV-I Tax1.

The expression and function of p53 tumor suppressor protein was investigated in T-cells immortalized by the Tax1 protein of HTLV-I. Conformationally wild-type p53 was expressed at elevated levels in Tax1-immortalized T-cells by post-transcriptional mechanisms when compared with normal T-cells. Luciferase assays with a reporter plasmid containing p53-binding sites revealed an impairment in the transactivating function of p53 in Tax1-immortalized T-cells. Our results suggest an important role for Tax1 in the aberrant expression and function of p53 observed in many HTLV-I transformed cells.