Mini spindles, the XMAP215 homologue, suppresses pausing of interphase microtubules in Drosophila

EMBO J. 2005 Apr 6;24(7):1387-96. doi: 10.1038/sj.emboj.7600629. Epub 2005 Mar 17.

Abstract

Drosophila Mini spindles (Msps) protein belongs to a conserved family of microtubule-associated proteins (MAPs). Intriguingly, this family of MAPs, including Xenopus XMAP215, was reported to have both microtubule stabilising and destabilising activities. While they are shown to regulate various aspects of microtubules, the role in regulating interphase microtubules in animal cells has yet to be established. Here, we show that the depletion or mutation of Msps prevents interphase microtubules from extending to the cell periphery and leads to the formation of stable microtubule bundles. The effect is independent of known Msps regulator or effector proteins, kinesin-13/KinI homologues or D-TACC. Real-time analysis revealed that the depletion of Msps results in a dramatic increase of microtubule pausing with little or no growth. Our study provides the first direct evidence to support a hypothesis that this family of MAPs acts as an antipausing factor to exhibit both microtubule stabilising and destabilising activities.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cells, Cultured
  • Drosophila / genetics
  • Drosophila / metabolism*
  • Drosophila Proteins / genetics
  • Drosophila Proteins / metabolism*
  • Fluorescence Recovery After Photobleaching
  • Green Fluorescent Proteins
  • Immunoblotting
  • Interphase / physiology*
  • Microscopy, Fluorescence
  • Microtubule-Associated Proteins / genetics
  • Microtubule-Associated Proteins / metabolism*
  • Microtubules / metabolism*
  • Microtubules / physiology
  • Molecular Sequence Data
  • RNA Interference
  • Sequence Alignment

Substances

  • Drosophila Proteins
  • Microtubule-Associated Proteins
  • msps protein, Drosophila
  • Green Fluorescent Proteins