Polo-like kinase controls vertebrate spindle elongation and cytokinesis

PLoS One. 2007 May 2;2(5):e409. doi: 10.1371/journal.pone.0000409.

Abstract

During cell division, chromosome segregation must be coordinated with cell cleavage so that cytokinesis occurs after chromosomes have been safely distributed to each spindle pole. Polo-like kinase 1 (Plk1) is an essential kinase that regulates spindle assembly, mitotic entry and chromosome segregation, but because of its many mitotic roles it has been difficult to specifically study its post-anaphase functions. Here we use small molecule inhibitors to block Plk1 activity at anaphase onset, and demonstrate that Plk1 controls both spindle elongation and cytokinesis. Plk1 inhibition did not affect anaphase A chromosome to pole movement, but blocked anaphase B spindle elongation. Plk1-inhibited cells failed to assemble a contractile ring and contract the cleavage furrow due to a defect in Rho and Rho-GEF localization to the division site. Our results demonstrate that Plk1 coordinates chromosome segregation with cytokinesis through its dual control of anaphase B and contractile ring assembly.

Publication types

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

MeSH terms

  • Cell Cycle Proteins / antagonists & inhibitors
  • Cell Cycle Proteins / metabolism*
  • Cell Cycle*
  • HeLa Cells
  • Humans
  • Protein Kinase Inhibitors / pharmacology
  • Protein-Serine-Threonine Kinases / antagonists & inhibitors
  • Protein-Serine-Threonine Kinases / metabolism*
  • Proto-Oncogene Proteins / antagonists & inhibitors
  • Proto-Oncogene Proteins / metabolism*
  • Spindle Apparatus*

Substances

  • Cell Cycle Proteins
  • Protein Kinase Inhibitors
  • Proto-Oncogene Proteins
  • Protein-Serine-Threonine Kinases
  • polo-like kinase 1