Molecular Biology of the Cell track citations

Home Help [Feedback] [For Subscribers] [Archive] [Search] --
QUICK SEARCH:   [advanced]


     

MBC in Press, published online ahead of print August 3, 2005
Mol. Biol. Cell 10.1091/mbc.E05-04-0315

A more recent version of this article appeared on October 1, 2005
This Article
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
E05-04-0315v1
16/10/4827    most recent
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Roig, J.
Right arrow Articles by Avruch, J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Roig, J.
Right arrow Articles by Avruch, J.

Submitted on April 15, 2005
Revised on July 21, 2005
Accepted on July 22, 2005

Active Nercc1 Protein Kinase Concentrates at Centrosomes Early in Mitosis and Is Necessary for Proper Spindle Assembly

Joan Roig,* Aaron Groen,{dagger} Jennifer Caldwell,{ddagger} and Joseph Avruch*

*Department of Molecular Biology and Medical Services, Massachusetts General Hospital and Department of Medicine, Harvard Medical School, Boston, MA 02114; {dagger}Department of Systems Biology, Harvard Medical School, Boston, MA 02115; {ddagger}MDS Proteomics, Charlottesville, VA 22911

Monitoring Editor: Yixian Zheng

The Nercc1 protein kinase autoactivates in vitro and is activated in vivo during mitosis. Autoactivation in vitro requires phosphorylation of the activation loop at threonine 210. Mitotic activation of Nercc1 in mammalian cells is accompanied by Thr210 phosphorylation, and involves a small fraction of total Nercc1. Mammalian Nercc1 coimmunoprecipitates {gamma}-tubulin and the activated Nercc1 polypeptides localize to the centrosomes and spindle poles during early mitosis, suggesting that active Nercc has important functions at the microtubular organizing center during cell division. To test this hypothesis, we characterized the Xenopus Nercc1 orthologue (XNercc). XNercc endogenous to meiotic egg extracts coprecipitates a multiprotein complex that contains {gamma}-tubulin and several components of the {gamma}-tubulin ring complex and localizes to the poles of spindles formed in vitro. Reciprocally, immunoprecipitates of the {gamma}-tubulin ring complex polypeptide Xgrip109 contain XNercc. Immunodepletion of XNercc from egg extracts results in delayed spindle assembly, fewer bipolar spindles, and the appearance of aberrant microtubule structures, aberrations corrected by addition of purified recombinant XNercc. XNercc immunodepletion also slows aster assembly induced by Ran-GTP, producing Ran-asters of abnormal size and morphology. Thus, Nercc1 contributes to both the centrosomal and the chromatin/Ran pathways that collaborate in the organization of a bipolar spindle. Keywords: Nek, mitosis, spindle, centrosome, {gamma}-tubulin.

Address correspondence to: Joan Roig (roig{at}molbio.mgh.harvard.edu) or Joseph Avruch (avruch{at}helix.mgh.harvard.edu)




This article has been cited by other articles:


Home page
 J. Biol. Chem.Home page
P. Rellos, F. J. Ivins, J. E. Baxter, A. Pike, T. J. Nott, D.-M. Parkinson, S. Das, S. Howell, O. Fedorov, Q. Y. Shen, et al.
Structure and Regulation of the Human Nek2 Centrosomal Kinase
J. Biol. Chem., March 2, 2007; 282(9): 6833 - 6842.
[Abstract] [Full Text] [PDF]

Home page
 J. Cell Sci.Home page
L. M. Quarmby and M. R. Mahjoub
Caught Nek-ing: cilia and centrioles
J. Cell Sci., November 15, 2005; 118(22): 5161 - 5169.
[Abstract] [Full Text] [PDF]


Home Help [Feedback] [For Subscribers] [Archive] [Search] --
Copyright © 2005 by The American Society for Cell Biology. Terms of copyright protection, warranties, and disclaimers.