Plk1-dependent recruitment of gamma-tubulin complexes to mitotic centrosomes involves multiple PCM components

PLoS One. 2009 Jun 19;4(6):e5976. doi: 10.1371/journal.pone.0005976.

Abstract

The nucleation of microtubules requires protein complexes containing gamma-tubulin, which are present in the cytoplasm and associate with the centrosome and with the mitotic spindle. We have previously shown that these interactions require the gamma-tubulin targeting factor GCP-WD/NEDD1, which has an essential role in spindle formation. The recruitment of additional gamma-tubulin to the centrosomes occurs during centrosome maturation at the G2/M transition and is regulated by the mitotic kinase Plk1. However, the molecular details of this important pathway are unknown and a Plk1 substrate that controls gamma-tubulin recruitment has not been identified. Here we show that Plk1 associates with GCP-WD in mitosis and Plk1 activity contributes to phosphorylation of GCP-WD. Plk1 depletion or inhibition prevents accumulation of GCP-WD at mitotic centrosomes, but GCP-WD mutants that are defective in Plk1-binding and -phosphorylation still accumulate at mitotic centrosomes and recruit gamma-tubulin. Moreover, Plk1 also controls the recruitment of other PCM proteins implicated in centrosomal gamma-tubulin attachment (Cep192/hSPD2, pericentrin, Cep215/Cdk5Rap2). Our results support a model in which Plk1-dependent recruitment of gamma-tubulin to mitotic centrosomes is regulated upstream of GCP-WD, involves multiple PCM proteins and therefore potentially multiple Plk1 substrates.

Publication types

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

MeSH terms

  • Cell Cycle Proteins / metabolism*
  • Cell Line, Tumor
  • Centrioles / metabolism*
  • Centrosome / metabolism*
  • Cloning, Molecular
  • HeLa Cells
  • Humans
  • Microscopy, Fluorescence / methods
  • Mitosis*
  • Models, Biological
  • Phosphorylation
  • Protein-Serine-Threonine Kinases / metabolism*
  • Proto-Oncogene Proteins / metabolism*
  • RNA / chemistry
  • RNA Interference
  • Spindle Apparatus
  • Tubulin / metabolism*

Substances

  • Cell Cycle Proteins
  • Proto-Oncogene Proteins
  • Tubulin
  • RNA
  • Protein-Serine-Threonine Kinases
  • polo-like kinase 1