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, 620K)
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 Murphy, S. M.
Right arrow Articles by Stearns, T.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Murphy, S. M.
Right arrow Articles by Stearns, T.
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//663 $5.00
The Journal of Cell Biology, Volume 141, Number 3, , 1998 663-674

Articles

The Mammalian {gamma}-Tubulin Complex Contains Homologues of the Yeast Spindle Pole Body Components Spc97p and Spc98p



Steven M. Murphy, Lenore Urbani, and Tim Stearns

Department of Biological Sciences, Stanford University, Stanford, California

{gamma}-Tubulin is a universal component of microtubule organizing centers where it is believed to play an important role in the nucleation of microtubule polymerization. {gamma}-Tubulin also exists as part of a cytoplasmic complex whose size and complexity varies in different organisms. To investigate the composition of the cytoplasmic {gamma}-tubulin complex in mammalian cells, cell lines stably expressing epitope-tagged versions of human {gamma}-tubulin were made. The epitope-tagged {gamma}-tubulins expressed in these cells localize to the centrosome and are incorporated into the cytoplasmic {gamma}-tubulin complex. Immunoprecipitation of this complex identifies at least seven proteins, with calculated molecular weights of 48, 71, 76, 100, 101, 128, and 211 kD. We have identified the 100- and 101-kD components of the {gamma}-tubulin complex as homologues of the yeast spindle pole body proteins Spc97p and Spc98p, and named the corresponding human proteins hGCP2 and hGCP3. Sequence analysis revealed that these proteins are not only related to their respective homologues, but are also related to each other. GCP2 and GCP3 colocalize with {gamma}-tubulin at the centrosome, cosediment with {gamma}-tubulin in sucrose gradients, and coimmunoprecipitate with {gamma}-tubulin, indicating that they are part of the {gamma}-tubulin complex. The conservation of a complex involving {gamma}-tubulin, GCP2, and GCP3 from yeast to mammals suggests that structurally diverse microtubule organizing centers such as the yeast spindle pole body and the animal centrosome share a common molecular mechanism for microtubule nucleation.

Abbreviations used in this paper: GCP, {gamma}-tubulin complex protein; GST, glutathione-S-transferase; SPB, spindle pole body.

Address all correspondence to T. Stearns, Department of Biological Sciences, Stanford University, Stanford, CA 94305-5020. Tel.: (650) 725-6934. Fax: (650) 725-8309. E-mail: stearns{at}stanford.edu


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