Polo-like kinase 1 and Chk2 interact and co-localize to centrosomes and the midbody

J Biol Chem. 2003 Mar 7;278(10):8468-75. doi: 10.1074/jbc.M211202200. Epub 2002 Dec 18.

Abstract

Chk2 is a protein kinase intermediary in DNA damage checkpoint pathways. DNA damage induces phosphorylation of Chk2 at multiple sites concomitant with activation. Chk2 phosphorylated at Thr-68 is found in nuclear foci at sites of DNA damage (1). We report here that Chk2 phosphorylated at Thr-68 and Thr-26 or Ser-28 is localized to centrosomes and midbodies in the absence of DNA damage. In a search for interactions between Chk2 and proteins with similar subcellular localization patterns, we found that Chk2 coimmunoprecipitates with Polo-like kinase 1, a regulator of chromosome segregation, mitotic entry, and mitotic exit. Plk1 overexpression enhances phosphorylation of Chk2 at Thr-68. Plk1 phosphorylates recombinant Chk2 in vitro. Indirect immunofluorescence (IF) microscopy revealed the co-localization of Chk2 and Plk1 to centrosomes in early mitosis and to the midbody in late mitosis. These findings suggest lateral communication between the DNA damage and mitotic checkpoints.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Cell Cycle Proteins
  • Cell Line
  • Centrosome / metabolism*
  • Checkpoint Kinase 2
  • Humans
  • Microscopy, Fluorescence
  • Plasmids
  • Polo-Like Kinase 1
  • Precipitin Tests
  • Protein Binding
  • Protein Kinases / metabolism*
  • Protein Serine-Threonine Kinases*
  • Proto-Oncogene Proteins
  • Recombinant Proteins / metabolism
  • Subcellular Fractions / metabolism

Substances

  • Cell Cycle Proteins
  • Proto-Oncogene Proteins
  • Recombinant Proteins
  • Protein Kinases
  • Checkpoint Kinase 2
  • CHEK2 protein, human
  • Protein Serine-Threonine Kinases