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

J. Biol. Chem., Vol. 283, Issue 42, 28392-28400, October 17, 2008

This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 283/42/28392    most recent M801801200v1 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 Asiedu, M. Articles by Wei, Q. Search for Related Content PubMed PubMed Citation Articles by Asiedu, M. Articles by Wei, Q. Social Bookmarking                      What's this?

Phosphorylation of MyoGEF on Thr-574 by Plk1 Promotes MyoGEF Localization to the Central Spindle^*

Michael Asiedu, Di Wu, Fumio Matsumura, and Qize Wei¹

From the Department of Biochemistry, Kansas State University, Manhattan, Kansas 66506 and the Department of Molecular Biology & Biochemistry, Rutgers University, Piscataway, New Jersey 08855

We reported previously that a guanine nucleotide exchange factor, MyoGEF, localizes to the central spindle, activates RhoA, and is required for cytokinesis. In this study, we have found that Plk1 (polo-like kinase 1) can phosphorylate MyoGEF, thereby recruiting MyoGEF to the central spindle as well as enhancing MyoGEF activity toward RhoA. The in vitro kinase assay shows that Plk1 can phosphorylate MyoGEF on threonine 574. Immunoprecipitation/immunoblot analysis demonstrates that mutation of threonine 574 to alanine dramatically decreases threonine phosphorylation of MyoGEF in transfected HeLa cells, suggesting that threonine 574 is phosphorylated in vivo. Consistent with these observations, immunofluorescence shows that Plk1 and MyoGEF colocalize at the spindle pole and central spindle during mitosis and cytokinesis. Importantly, RNA interference-mediated depletion of Plk1 interferes with the localization of MyoGEF at the spindle pole and central spindle. Moreover, mutation of threonine 574 to alanine in MyoGEF or depletion of Plk1 by RNA interference leads to a decrease in MyoGEF activity toward RhoA in HeLa cells. Therefore, our results suggest that Plk1 can regulate MyoGEF activity and localization, contributing to the regulation of cytokinesis.

Received for publication, March 6, 2008 , and in revised form, August 5, 2008.

^* This work was supported, in whole or in part, by National Institutes of Health Grants k22 HL071542 (to Q. W.) and P20 RR17708 and P20 RR15563. This work was also supported by a fund from the Terry C. Johnson Center for Basic Cancer Research (to Q. W.). This is contribution 08-296-J from the Kansas Agricultural Experiment Station (Manhattan, KS). 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 Movie S1 and Fig. S1.

¹ To whom correspondence should be addressed: Dept. of Biochemistry, Kansas State University, 141 Chalmers Hall, Manhattan, KS 66506. Tel.: 785-532-6736; Fax: 785-532-7278; E-mail: weiq{at}ksu.edu.

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

This article has been cited by other articles:

				M. Asiedu, D. Wu, F. Matsumura, and Q. Wei Centrosome/Spindle Pole-associated Protein Regulates Cytokinesis via Promoting the Recruitment of MyoGEF to the Central Spindle Mol. Biol. Cell, March 1, 2009; 20(5): 1428 - 1440. [Abstract] [Full Text] [PDF]