In vitro reconstitution of centrosome assembly and function: the central role of gamma-tubulin

Cell. 1994 Feb 25;76(4):623-37. doi: 10.1016/0092-8674(94)90503-7.


The centrosome nucleates microtubule polymerization, affecting microtubule number, polarity, and structure. We use an in vitro system based on extracts of Xenopus eggs to examine the role of gamma-tubulin in centrosome assembly and function. gamma-Tubulin is present in the cytoplasm of frog eggs and vertebrate somatic cells in a large approximately 25S complex. The egg extracts assemble centrosomes around sperm centrioles. Formation of a centrosome in the extract requires both the gamma-tubulin complex and ATP and can take place in the absence of microtubules. gamma-Tubulin is not present on the sperm prior to incubation in extract, but is recruited from the cytoplasm during centrosome assembly. The gamma-tubulin complex also binds to microtubules, likely the minus end, independent of the centrosome. These results suggest that gamma-tubulin is an essential component of the link between the centrosome and the microtubule, probably playing a direct role in microtubule nucleation.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Cytoplasm / ultrastructure
  • Cytoskeleton / ultrastructure*
  • Male
  • Microscopy, Fluorescence
  • Microtubule-Associated Proteins / immunology
  • Microtubule-Associated Proteins / metabolism*
  • Microtubules / metabolism*
  • Oocytes / ultrastructure
  • Solubility
  • Spermatozoa / ultrastructure
  • Spindle Apparatus / ultrastructure
  • Tetrahymena / ultrastructure
  • Tubulin / metabolism*
  • Xenopus laevis


  • Microtubule-Associated Proteins
  • Tubulin