JCB logo
Avanti Polar Lipids, Inc.
  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents
This Article
Right arrow Full Text
Right arrow Full Text (PDF, 7638K)
Right arrow PPT slides of all figures
Right arrow Alert me when this article is cited
Right arrow Citation Map
Services
Right arrow Email this article
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new content in the JCB
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Tassin, A.-M.
Right arrow Articles by Bornens, M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Tassin, A.-M.
Right arrow Articles by Bornens, M.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Facebook   Add to Reddit   Add to Technorati   Add to Twitter  
What's this?

© The Rockefeller University Press, 0021-9525/1998//689 $5.00
The Journal of Cell Biology, Volume 141, Number 3, , 1998 689-701

Articles

Characterization of the Human Homologue of the Yeast Spc98p and Its Association with {gamma}-Tubulin



Anne-Marie Tassin, Claude Celati, Mohammed Moudjou, and Michel Bornens

Institut Curie, Section Recherche, Unité Mixte de Recherche 144 du Centre National de la Recherche Scientifique, 75248 Paris Cedex 05, France

A trimeric complex formed by Tub4p, the budding yeast {gamma}-tubulin, and the two spindle pole body components, Spc98p and Spc97p, has recently been characterized in Saccharomyces cerevisiae. We reasoned that crucial functions, such as the control of microtubule nucleation, could be maintained among divergent species. SPC98-related sequences were searched in dbEST using the BLASTN program. Primers derived from the human expressed sequence tag matching SPC98 were used to clone the 5' and 3' cDNA ends by rapid amplification of cDNA ends (RACE)-PCR. The human Spc98 cDNA presents an alternative splicing at the 3' end. The deduced protein possesses 22% identity and 45% similarity with the yeast homologue. We further report that the human Spc98p, like {gamma}-tubulin, is concentrated at the centrosome, although a large fraction is found in cytosolic complexes. Sucrose gradient sedimentation of the cytosolic fraction and immunoprecipitation experiments demonstrate that both {gamma}-tubulin and HsSpc98p are in the same complex. Interestingly, Xenopus sperm centrosomes, which are incompetent for microtubule nucleation before their activation in the egg cytoplasm, were found to contain similar amounts of both Spc98p and {gamma}-tubulin to human somatic centrosomes, which are competent for microtubule nucleation. Finally, affinity-purified antibodies against Spc98p inhibit microtubule nucleation on isolated centrosomes, as well as in microinjected cells, suggesting that this novel protein is indeed required for the nucleation reaction.

Abbreviations used in this paper: EST, expressed sequence tag; PCM, pericentriolar material; RACE, rapid amplification of cDNA ends; SPB, spindle pole body; {gamma}-TuRC, {gamma}-tubulin ring complex.

Address all correspondence to Anne-Marie Tassin, Institut Curie, Section Recherche, UMR 144 du Centre National de la Recherche Scientifique (CNRS), 26 rue d'Ulm, 75248 Paris Cedex 05, France. Tel.: (33) 1 42346403. Fax: (33) 1 42346421. E-mail: atassin{at}curie.fr


Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Facebook Facebook   Add to Reddit Reddit   Add to Technorati Technorati   Add to Twitter Twitter    What's this?


This article has been cited by other articles:



  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents