Centrioles resist forces applied on centrosomes during G2/M transition

Biol Cell. 2005 Jun;97(6):425-34. doi: 10.1042/BC20040112.

Abstract

Background information: Centrosome movements at the onset of mitosis result from a balance between the pulling and pushing forces mediated by microtubules. The structural stability of the centrosome core structure, the centriole pair, is correlated with a heavy polyglutamylation of centriole tubulin.

Results: Using HeLa cells stably expressing centrin-green fluorescent protein as a centriole marker, we monitored the effect of microinjecting an anti-(polyglutamylated tubulin) monoclonal antibody, GT335, in G1/S or G2 cells. In contrast with the slow effect of the monoclonal antibody GT335 during interphase, a dramatic and rapid centrosome fragmentation occurred in cells microinjected in G2 that was both Eg5- and dynein-dependent. Inhibition of either one of these two motors significantly decreased the scattering of centrosome fragments, and inhibition of centrosome segregation by impairing microtubule dynamics abolished centrosome fragmentation.

Conclusions: Our results demonstrate that the compact structure of the mitotic centrosome is capable of absorbing most of the pulling and pushing forces during G2/M transition and suggest that centrosomes could act as mechanosensors integrating tensions during cell division.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Monoclonal / chemistry
  • Cell Cycle
  • Cell Division
  • Centrioles / metabolism
  • Centrioles / ultrastructure*
  • Centrosome / metabolism
  • Centrosome / ultrastructure
  • Dyneins / metabolism
  • G1 Phase
  • G2 Phase
  • Green Fluorescent Proteins / metabolism
  • HeLa Cells
  • Humans
  • Kinesin / metabolism
  • Microscopy, Fluorescence
  • Microscopy, Video
  • Models, Biological
  • Molecular Motor Proteins
  • Peptides / chemistry
  • S Phase
  • Time Factors
  • Tubulin / chemistry

Substances

  • Antibodies, Monoclonal
  • KIF11 protein, human
  • Molecular Motor Proteins
  • Peptides
  • Tubulin
  • Green Fluorescent Proteins
  • polyglutamine
  • Dyneins
  • Kinesin