Phosphorylation of PCNA by EGFR inhibits mismatch repair and promotes misincorporation during DNA synthesis

Proc Natl Acad Sci U S A. 2015 May 5;112(18):5667-72. doi: 10.1073/pnas.1417711112. Epub 2015 Mar 30.

Abstract

Proliferating cell nuclear antigen (PCNA) plays essential roles in eukaryotic cells during DNA replication, DNA mismatch repair (MMR), and other events at the replication fork. Earlier studies show that PCNA is regulated by posttranslational modifications, including phosphorylation of tyrosine 211 (Y211) by the epidermal growth factor receptor (EGFR). However, the functional significance of Y211-phosphorylated PCNA remains unknown. Here, we show that PCNA phosphorylation by EGFR alters its interaction with mismatch-recognition proteins MutSα and MutSβ and interferes with PCNA-dependent activation of MutLα endonuclease, thereby inhibiting MMR at the initiation step. Evidence is also provided that Y211-phosphorylated PCNA induces nucleotide misincorporation during DNA synthesis. These findings reveal a novel mechanism by which Y211-phosphorylated PCNA promotes cancer development and progression via facilitating error-prone DNA replication and suppressing the MMR function.

Keywords: EGFR; PCNA phosphorylation; cancer; genome instability; mismatch repair.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line, Tumor
  • Cell Proliferation
  • Colorectal Neoplasms / metabolism
  • DNA / biosynthesis*
  • DNA Mismatch Repair*
  • Disease Progression
  • ErbB Receptors / metabolism*
  • Genome
  • Genome, Human
  • HeLa Cells
  • Humans
  • Microscopy, Fluorescence
  • Models, Molecular
  • Mutation
  • Neoplasms / genetics
  • Neoplasms / metabolism*
  • Phosphorylation
  • Proliferating Cell Nuclear Antigen / metabolism*
  • Protein Binding
  • Sequence Analysis, DNA
  • Tyrosine / chemistry

Substances

  • Proliferating Cell Nuclear Antigen
  • Tyrosine
  • DNA
  • ErbB Receptors