Regulated HsSAS-6 levels ensure formation of a single procentriole per centriole during the centrosome duplication cycle

Dev Cell. 2007 Aug;13(2):203-13. doi: 10.1016/j.devcel.2007.07.004.

Abstract

Centrosome duplication involves the formation of a single procentriole next to each centriole, once per cell cycle. The mechanisms governing procentriole formation and those restricting its occurrence to one event per centriole are poorly understood. Here, we show that HsSAS-6 is necessary for procentriole formation and that it localizes asymmetrically next to the centriole at the onset of procentriole formation. HsSAS-6 levels oscillate during the cell cycle, with the protein being degraded in mitosis and starting to accumulate again at the end of the following G1. Our findings indicate that APC(Cdh1) targets HsSAS-6 for degradation by the 26S proteasome. Importantly, we demonstrate that increased HsSAS-6 levels promote formation of more than one procentriole per centriole. Therefore, regulated HsSAS-6 levels normally ensure that each centriole seeds the formation of a single procentriole per cell cycle, thus playing a fundamental role in driving the centrosome duplication cycle and ensuring genome integrity.

Publication types

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

MeSH terms

  • Anaphase
  • Cell Cycle Proteins / chemistry
  • Cell Cycle Proteins / metabolism*
  • Cell Cycle*
  • Centrioles / metabolism*
  • Centrioles / ultrastructure
  • HeLa Cells
  • Humans
  • Models, Biological
  • Proteasome Endopeptidase Complex / metabolism
  • Protein Processing, Post-Translational
  • Protein Structure, Tertiary
  • Protein Transport
  • Protein-Serine-Threonine Kinases / metabolism

Substances

  • Cell Cycle Proteins
  • SASS6 protein, human
  • PLK4 protein, human
  • Protein-Serine-Threonine Kinases
  • Proteasome Endopeptidase Complex
  • ATP dependent 26S protease