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

J. Biol. Chem., Vol. 283, Issue 10, 6040-6049, March 7, 2008

This Article Full Text Full Text (PDF) All Versions of this Article: 283/10/6040    most recent M708248200v1 Alert me when this article is cited 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 Google Scholar Articles by Ashe, M. Articles by Wittenberg, C. PubMed PubMed Citation Articles by Ashe, M. Articles by Wittenberg, C. Social Bookmarking                      What's this?

The SBF- and MBF-associated Protein Msa1 Is Required for Proper Timing of G₁-specific Transcription in Saccharomyces cerevisiae^*

Mabelle Ashe, Robertus A. M. de Bruin, Tatyana Kalashnikova, W. Hayes McDonald¹, John R. Yates, III, and Curt Wittenberg²

From the Departments of Molecular Biology and Cell Biology, The Scripps Research Institute, La Jolla, California 92037

In the budding yeast Saccharomyces cerevisiae, cell cycle initiation is prompted during G₁ phase by Cln3/cyclin-dependent protein kinase-mediated transcriptional activation of G₁-specific genes. A recent screening performed to reveal novel interactors of SCB-binding factor (SBF) and MCB-binding factor (MBF) identified, in addition to the SBF-specific repressor Whi5 and the MBF-specific corepressor Nrm1, a pair of homologous proteins, Msa1 and Msa2 (encoded by YOR066w and YKR077w), as interactors of SBF and MBF, respectively. MSA1 is expressed periodically during the cell cycle with peak mRNA levels occurring at the late M/early G₁ phase and peak protein levels occurring in early G₁. Msa1 associates with SBF- and MBF-regulated target promoters consistent with a role in G₁-specific transcriptional regulation. Msa1 affects cell cycle initiation by advancing the timing of transcription of G₁-specific genes. Msa1 binds to SBF- and MBF-regulated promoters and binding is maximal during the G₁ phase. Binding depends upon the cognate transcription factor. Msa1 overexpression advances the timing of SBF-dependent transcription and budding, whereas depletion delays both indicators of cell cycle initiation. Similar effects on MBF-regulated transcription are observed. Based upon these results, we conclude that Msa1 acts to advance the timing of G₁-specific transcription and cell cycle initiation.

Received for publication, October 3, 2007 , and in revised form, December 13, 2007.

^* This work was supported by United States Public Health Service Grants GM059441 and GM043487 (to C. W.) and Grant P4 1RR11823 from the National Center for Research Resources of the National Institutes of Health (to T. N. D.). 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.

¹ Present address: Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831.

² To whom correspondence should be addressed: Dept. of Molecular Biology, MB-3, The Scripps Research Institute, 10550 North Torrey Pines Rd., La Jolla, CA 92037. E-mail: curtw{at}scripps.edu.

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