Transcriptional repression of p53 by human T-cell leukemia virus type I Tax protein. The state of the art may have changed since the publication date. Transcriptional repression of p53 by human T-cell leukemia virus type I Tax protein. J Biol Chem.
Tax transcriptionally deregulates a wide variety of viral and cellular genes.
Tax deregulation of gene expression is mediated through interaction with a variety of structurally unrelated cellular transcription factors, as Tax does not bind DNA in a sequence-specific manner. In this report, we examined whether Tax might repress transcription of the tumor suppressor p53, as the p53 gene has recently been demonstrated to be regulated by the bHLH protein c-Myc. Furthermore, loss or inactivation of the p53 gene has been shown to be causally associated with oncogenic transformation. We show that Tax represses transcription of the p53 gene and that this repression is dependent upon the bHLH recognition element in the p53 promoter. Together, these results suggest that Tax may promote malignant transformation through repression of p53 transcription.