Hepatitis C virus NS5A physically associates with p53 and regulates p21/waf1 gene expression in a p53-dependent manner

N. Majumder, A. K. Ghosh, R. Steele, R. Ray, R. B. Ray

Research output: Contribution to journalArticle

197 Scopus citations


We have previously demonstrated that hepatitis C virus (HCV) NS5A protein promotes cell growth and transcriptionally regulates the p21/waf1 promoter, a downstream effector gene of p53. In this study, we investigated the molecular mechanism of NS5A-mediated transcriptional repression of p21/waf1. We observed that transcriptional repression of the p21/waf1 gene by NS5A is p53 dependent by using p53 wild-type (+/+) and null (-/-) cells. Interestingly, p53-mediated transcriptional activation from a synthetic promoter containing multiple p53 binding sites (PG13-LUC) was abrogated following expression of HCV NS5A. Additional studies using pull-down experiments, in vivo coimmunoprecipitation, and mammalian two-hybrid assays demonstrated that NS5A physically associates with p53. Confocal microscopy revealed sequestration of p53 in the perinuclear membrane and colocalization with NS5A in transfected HepG2 and Saos-2 cells. Together these results suggest that an association of NS5A and p53 allows transcriptional modulation of the p21/waf1 gene and may contribute to HCV-mediated pathogenesis.

Original languageEnglish (US)
Pages (from-to)1401-1407
Number of pages7
JournalJournal of virology
Issue number3
StatePublished - Feb 5 2001


ASJC Scopus subject areas

  • Microbiology
  • Immunology
  • Insect Science
  • Virology

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