Murine CENP-F regulates centrosomal microtubule nucleation and interacts with Hook2 at the centrosome

Mol Biol Cell. 2009 Nov;20(22):4790-803. doi: 10.1091/mbc.e09-07-0560. Epub 2009 Sep 30.

Abstract

The microtubule (MT) network is essential in a broad spectrum of cellular functions. Many studies have linked CENP-F to MT-based activities as disruption of this protein leads to major changes in MT structure and function. Still, the basis of CENP-F regulation of the MT network remains elusive. Here, our studies reveal a novel and critical localization and role for CENP-F at the centrosome, the major MT organizing center (MTOC) of the cell. Using a yeast two-hybrid screen, we identify Hook2, a linker protein that is essential for regulation of the MT network at the centrosome, as a binding partner of CENP-F. With recently developed immunochemical reagents, we confirm this interaction and reveal the novel localization of CENP-F at the centrosome. Importantly, in this first report of CENP-F(-/-) cells, we demonstrate that ablation of CENP-F protein function eliminates MT repolymerization after standard nocodazole treatment. This inhibition of MT regrowth is centrosome specific because MT repolymerization is readily observed from the Golgi in CENP-F(-/-) cells. The centrosome-specific function of CENP-F in the regulation of MT growth is confirmed by expression of truncated CENP-F containing only the Hook2-binding domain. Furthermore, analysis of partially reconstituted MTOC asters in cells that escape complete repolymerization block shows that disruption of CENP-F function impacts MT nucleation and anchoring rather than promoting catastrophe. Our study reveals a major new localization and function of CENP-F at the centrosome that is likely to impact a broad array of MT-based actions in the cell.

Publication types

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

MeSH terms

  • Animals
  • COS Cells
  • Cell Line
  • Centrosome / metabolism*
  • Chlorocebus aethiops
  • Chromosomal Proteins, Non-Histone / genetics
  • Chromosomal Proteins, Non-Histone / metabolism*
  • Humans
  • Mice
  • Mice, Knockout
  • Microfilament Proteins / genetics
  • Microfilament Proteins / metabolism*
  • Microtubule-Associated Proteins / genetics
  • Microtubule-Associated Proteins / metabolism*
  • Microtubule-Organizing Center / metabolism
  • Microtubules / drug effects
  • Microtubules / metabolism*
  • Nocodazole / pharmacology
  • Tubulin Modulators / pharmacology
  • Two-Hybrid System Techniques

Substances

  • Chromosomal Proteins, Non-Histone
  • Hook2 protein, human
  • Hook2 protein, mouse
  • Microfilament Proteins
  • Microtubule-Associated Proteins
  • Tubulin Modulators
  • centromere protein F
  • Nocodazole