Cnn1 inhibits the interactions between the KMN complexes of the yeast kinetochore

Nat Cell Biol. 2012 May 6;14(6):614-24. doi: 10.1038/ncb2495.

Abstract

Kinetochores attach the replicated chromosomes to the mitotic spindle and orchestrate their transmission to the daughter cells. Kinetochore-spindle binding and chromosome segregation are mediated by the multi-copy KNL1(Spc105), MIS12(Mtw1) and NDC80(Ndc80) complexes that form the so-called KMN network. KMN-spindle attachment is regulated by the Aurora B(Ipl1) and MPS1(Mps1) kinases. It is unclear whether other mechanisms exist that support KMN activity during the cell cycle. Using budding yeast, we show that kinetochore protein Cnn1 localizes to the base of the Ndc80 complex and promotes a functionally competent configuration of the KMN network. Cnn1 regulates KMN activity in a spatiotemporal manner by inhibiting the interaction between its complexes. Cnn1 activity peaks in anaphase and is driven by the Cdc28, Mps1 and Ipl1 kinases.

Publication types

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

MeSH terms

  • Anaphase
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism*
  • Chromosomes, Fungal / metabolism
  • Kinetochores / metabolism*
  • Microtubule-Associated Proteins / genetics
  • Microtubule-Associated Proteins / metabolism*
  • Phosphorylation
  • Protein Binding
  • Protein-Serine-Threonine Kinases / genetics
  • Protein-Serine-Threonine Kinases / metabolism*
  • Saccharomyces cerevisiae / cytology
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Spindle Apparatus / metabolism

Substances

  • Cell Cycle Proteins
  • Cnn1 protein, S cerevisiae
  • MTW1 protein, S cerevisiae
  • Microtubule-Associated Proteins
  • Saccharomyces cerevisiae Proteins
  • Spc105 protein, S cerevisiae
  • Protein-Serine-Threonine Kinases
  • MPS1 protein, S cerevisiae