CDK-dependent phosphorylation and nuclear exclusion coordinately control kinetochore assembly state

J Cell Biol. 2013 Apr 1;201(1):23-32. doi: 10.1083/jcb.201301006. Epub 2013 Mar 25.

Abstract

Accurate chromosome segregation requires assembly of the multiprotein kinetochore complex. Prior work has identified more than 100 different kinetochore components in human cells. However, little is known about the regulatory processes that specify their assembly upon mitotic entry and disassembly at mitotic exit. In this paper, we used a live-cell imaging-based assay to quantify kinetochore disassembly kinetics and systematically analyze the role of potential regulatory mechanisms in controlling kinetochore assembly state. We find that kinetochore assembly and disassembly was driven primarily by mitotic phosphorylation downstream of cyclin-dependent kinase (CDK). In addition, we demonstrate that nuclear exclusion of the Ndc80 complex helped restrict kinetochore formation to mitosis. Combining constitutive CDK-dependent phosphorylation of CENP-T and forced nuclear localization of the Ndc80 complex partially prevented kinetochore disassembly at mitotic exit and led to chromosome segregation defects in subsequent divisions. In total, we find that the coordinated temporal regulation of outer kinetochore assembly is essential for accurate cell division.

Publication types

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

MeSH terms

  • Active Transport, Cell Nucleus / physiology
  • Cell Line
  • Cell Nucleus / genetics
  • Cell Nucleus / metabolism*
  • Chromosomal Proteins, Non-Histone / genetics
  • Chromosomal Proteins, Non-Histone / metabolism
  • Chromosome Segregation / physiology*
  • Cyclin-Dependent Kinases / genetics
  • Cyclin-Dependent Kinases / metabolism*
  • Cytoskeletal Proteins
  • Humans
  • Kinetochores / metabolism*
  • Mitosis / physiology*
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism
  • Phosphorylation / physiology

Substances

  • CENPT protein, human
  • Chromosomal Proteins, Non-Histone
  • Cytoskeletal Proteins
  • NDC80 protein, human
  • Nuclear Proteins
  • Cyclin-Dependent Kinases