The pseudo GTPase CENP-M drives human kinetochore assembly

Elife. 2014 Jul 8:3:e02978. doi: 10.7554/eLife.02978.

Abstract

Kinetochores, multi-subunit complexes that assemble at the interface with centromeres, bind spindle microtubules to ensure faithful delivery of chromosomes during cell division. The configuration and function of the kinetochore-centromere interface is poorly understood. We report that a protein at this interface, CENP-M, is structurally and evolutionarily related to small GTPases but is incapable of GTP-binding and conformational switching. We show that CENP-M is crucially required for the assembly and stability of a tetramer also comprising CENP-I, CENP-H, and CENP-K, the HIKM complex, which we extensively characterize through a combination of structural, biochemical, and cell biological approaches. A point mutant affecting the CENP-M/CENP-I interaction hampers kinetochore assembly and chromosome alignment and prevents kinetochore recruitment of the CENP-T/W complex, questioning a role of CENP-T/W as founder of an independent axis of kinetochore assembly. Our studies identify a single pathway having CENP-C as founder, and CENP-H/I/K/M and CENP-T/W as CENP-C-dependent followers.DOI: http://dx.doi.org/10.7554/eLife.02978.001.

Keywords: centromeres; kinetochores; mitosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Cell Cycle Proteins
  • Chromosomal Proteins, Non-Histone / chemistry
  • Chromosomal Proteins, Non-Histone / genetics
  • Chromosomal Proteins, Non-Histone / metabolism*
  • Crystallography, X-Ray
  • GTP Phosphohydrolases / chemistry
  • GTP Phosphohydrolases / genetics
  • GTP Phosphohydrolases / metabolism*
  • HeLa Cells
  • Humans
  • Kinetochores / chemistry
  • Kinetochores / metabolism*
  • Models, Biological
  • Models, Molecular
  • Molecular Sequence Data
  • Multiprotein Complexes / chemistry
  • Multiprotein Complexes / genetics
  • Multiprotein Complexes / metabolism
  • Mutation
  • Nuclear Proteins / chemistry
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Protein Folding
  • Protein Stability
  • Protein Structure, Quaternary
  • Protein Subunits
  • RNA, Small Interfering / genetics
  • Sequence Homology, Amino Acid

Substances

  • CENPM protein, human
  • Cell Cycle Proteins
  • Chromosomal Proteins, Non-Histone
  • Multiprotein Complexes
  • Nuclear Proteins
  • Protein Subunits
  • RNA, Small Interfering
  • GTP Phosphohydrolases

Grants and funding

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.