HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

J. Biol. Chem., Vol. 281, Issue 50, 38293-38301, December 15, 2006

This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 281/50/38293    most recent M607203200v1 Submit a Letter to Editor Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Albee, A. J. Articles by Wiese, C. Search for Related Content PubMed PubMed Citation Articles by Albee, A. J. Articles by Wiese, C. Social Bookmarking                      What's this?

Phosphorylation of Maskin by Aurora-A Is Regulated by RanGTP and Importin ^*

From the Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706

Mitotic spindle assembly in Xenopus egg extracts is regulated at least in part by importin and its regulator, the small GTPase, Ran. RanGTP stabilizes microtubules near the chromosomes during spindle assembly by selectively releasing spindle assembly factors from inhibition by importin / in the vicinity of the chromosomes. Several spindle assembly factors are regulated in this manner. We identified maskin, the Xenopus member of the transforming acidic coiled coil family of proteins, as a potential candidate in a two-step affinity chromatography approach designed to uncover additional downstream targets of importin / in mitosis. Here, we show that although maskin lacks a canonical nuclear localization sequence, it binds importin in a RanGTP-regulated manner. We further show that importin inhibits the regulatory phosphorylation of maskin by Aurora-A. This suggests a novel mechanism by which importin regulates the activity of a spindle assembly factor.

Received for publication, July 28, 2006 , and in revised form, September 12, 2006.

^* This work was supported by National Science Foundation Grant MCB-0344723 (to C. W.), a Kimmel Scholar Award from the Sidney Kimmel Foundation for Cancer Research (to C. W.), a Steenbock Predoctoral Fellowship from the Dept. of Biochemistry (to A. J. A.), and start-up funds from the University of Wisconsin, Madison, Graduate School, the College of Agricultural and Life Sciences, and the Department of Biochemistry. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement"in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

The on-line version of this article (available at http://www.jbc.org) contains supplemental Fig. S1.

¹ Current address: School of Life Sciences, Peking University, Beijing 100871, China.

² To whom correspondence should be addressed: 433 Babcock Dr., Madison, WI 53706. Tel.: 608-263-7608; Fax: 608-262-3453; E-mail: wiese{at}biochem.wisc.edu.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				A. J. Albee and C. Wiese Xenopus TACC3/Maskin Is Not Required for Microtubule Stability but Is Required for Anchoring Microtubules at the Centrosome Mol. Biol. Cell, August 1, 2008; 19(8): 3347 - 3356. [Abstract] [Full Text] [PDF]

				P. Kalab and R. Heald The RanGTP gradient - a GPS for the mitotic spindle J. Cell Sci., May 15, 2008; 121(10): 1577 - 1586. [Abstract] [Full Text] [PDF]