HPV-16 E2 contributes to induction of HPV-16 late gene expression by inhibiting early polyadenylation

EMBO J. 2012 May 22;31(14):3212-27. doi: 10.1038/emboj.2012.147.

Abstract

We provide evidence that the human papillomavirus (HPV) E2 protein regulates HPV late gene expression. High levels of E2 caused a read-through at the early polyadenylation signal pAE into the late region of the HPV genome, thereby inducing expression of L1 and L2 mRNAs. This is a conserved property of E2 of both mucosal and cutaneous HPV types. Induction could be reversed by high levels of HPV-16 E1 protein, or by the polyadenylation factor CPSF30. HPV-16 E2 inhibited polyadenylation in vitro by preventing the assembly of the CPSF complex. Both the N-terminal and hinge domains of E2 were required for induction of HPV late gene expression in transfected cells as well as for inhibition of polyadenylation in vitro. Finally, overexpression of HPV-16 E2 induced late gene expression from a full-length genomic clone of HPV-16. We speculate that the accumulation of high levels of E2 during the viral life cycle, not only turns off the expression of the pro-mitotic viral E6 and E7 genes, but also induces the expression of the late HPV genes L1 and L2.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Capsid Proteins / biosynthesis
  • Capsid Proteins / genetics
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Gene Expression Regulation, Viral / physiology*
  • HeLa Cells
  • Human papillomavirus 16 / physiology*
  • Humans
  • Oncogene Proteins, Viral / biosynthesis
  • Oncogene Proteins, Viral / genetics
  • Oncogene Proteins, Viral / metabolism*
  • Polyadenylation / physiology*
  • RNA 3' Polyadenylation Signals / physiology*
  • RNA, Viral / genetics
  • RNA, Viral / metabolism*
  • Repressor Proteins / genetics
  • Repressor Proteins / metabolism

Substances

  • Capsid Proteins
  • DNA-Binding Proteins
  • E2 protein, Human papillomavirus type 16
  • E6 protein, Human papillomavirus type 16
  • L2 protein, Human papillomavirus type 16
  • Oncogene Proteins, Viral
  • RNA, Viral
  • Repressor Proteins
  • oncogene protein E7, Human papillomavirus type 6
  • L1 protein, Human papillomavirus type 16