Control of microtubule dynamics by the antagonistic activities of XMAP215 and XKCM1 in Xenopus egg extracts

Nat Cell Biol. 2000 Jan;2(1):13-9. doi: 10.1038/71330.


Microtubules are dynamic polymers that move stochastically between periods of growth and shrinkage, a property known as dynamic instability. Here, to investigate the mechanisms regulating microtubule dynamics in Xenopus egg extracts, we have cloned the complementary DNA encoding the microtubule-associated protein XMAP215 and investigated the function of the XMAP215 protein. Immunodepletion of XMAP215 indicated that it is a major microtubule-stabilizing factor in Xenopus egg extracts. During interphase, XMAP215 stabilizes microtubules primarily by opposing the activity of the destabilizing factor XKCM1, a member of the kinesin superfamily. These results indicate that microtubule dynamics in Xenopus egg extracts are regulated by a balance between a stabilizing factor, XMAP215, and a destabilizing factor, XKCM1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cloning, Molecular
  • DNA, Complementary / genetics
  • Evolution, Molecular
  • Fluorescent Antibody Technique, Indirect
  • Kinesin / genetics
  • Kinesin / metabolism*
  • Microtubule-Associated Proteins / genetics
  • Microtubule-Associated Proteins / metabolism*
  • Microtubules / metabolism*
  • Mitosis / genetics
  • Molecular Sequence Data
  • Oocytes / metabolism*
  • Phylogeny
  • Rabbits
  • Sequence Homology, Amino Acid
  • Spindle Apparatus / physiology
  • Xenopus
  • Xenopus Proteins*


  • CKAP5 protein, Xenopus
  • DNA, Complementary
  • KIF11 protein, Xenopus
  • Microtubule-Associated Proteins
  • Xenopus Proteins
  • Kinesin

Associated data

  • GENBANK/AJ251130