HPV E6 proteins interact with specific PML isoforms and allow distinctions to be made between different POD structures

Oncogene. 2004 Jun 10;23(27):4662-72. doi: 10.1038/sj.onc.1207631.

Abstract

Mucosal human papillomaviruses (HPVs) are the causative agents of a number of human pathologies, including benign condylomas, as well as of the majority of cervical cancers and their high-grade precursor lesions. Although the viral E6 protein is known to be essential for driving malignant progression of HPV-infected cells, there are still many uncertainties about its mode of action. In this study, we have analysed the intracellular distribution of the E6 oncoproteins from the high-risk HPV-18 and the low-risk HPV-11. We show that both E6 proteins localize within the nucleus in nuclear bodies that are confocal with the promyelocytic leukaemia (PML) protein. Using a panel of different PML isoforms, we demonstrate specific co-localization between the E6 proteins and PML isoforms I-IV, but not with PML isoforms V and VI. We also demonstrate the interaction between E6 and a subset of PML isoforms in vivo. As a consequence of this interaction, the insoluble form of PML IV is destabilized by HPV-18 E6 through a proteasome-dependent pathway. Interestingly, both HPV-11 E6 and HPV-18 E6 can readily overcome PML IV-induced cellular senescence in primary cells. These results show separable functions for different PML isoforms that are specifically targeted by the HPV E6 oncoproteins.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alternative Splicing
  • Animals
  • Antibodies, Monoclonal / metabolism
  • Blotting, Western
  • Cell Line, Tumor
  • Cell Nucleus / metabolism*
  • Cell Transformation, Neoplastic
  • Cysteine Endopeptidases / metabolism
  • Fibroblasts / cytology
  • Fibroblasts / metabolism*
  • Fibroblasts / virology
  • Fluorescent Antibody Technique, Direct
  • Humans
  • Microscopy, Confocal
  • Multienzyme Complexes / metabolism
  • Oncogene Proteins, Viral / analysis
  • Oncogene Proteins, Viral / genetics
  • Oncogene Proteins, Viral / metabolism*
  • Papillomaviridae / metabolism*
  • Precipitin Tests
  • Proteasome Endopeptidase Complex
  • Protein Isoforms / genetics
  • Protein Isoforms / metabolism*
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Rats

Substances

  • Antibodies, Monoclonal
  • Multienzyme Complexes
  • Oncogene Proteins, Viral
  • Protein Isoforms
  • RNA, Messenger
  • Cysteine Endopeptidases
  • Proteasome Endopeptidase Complex