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

J. Biol. Chem., Vol. 282, Issue 24, 17563-17567, June 15, 2007

This Article Full Text Full Text (PDF) All Versions of this Article: 282/24/17563    most recent M700454200v1 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 Stevens, H. C. Articles by Nichols, J. W. Search for Related Content PubMed PubMed Citation Articles by Stevens, H. C. Articles by Nichols, J. W. Social Bookmarking                      What's this?

The Proton Electrochemical Gradient across the Plasma Membrane of Yeast Is Necessary for Phospholipid Flip^*

From the Department of Physiology, Emory University School of Medicine, Atlanta, Georgia 30322

Recently, two members of the P4 family of P-type ATPases, Dnf1p and Dnf2p, were shown to be necessary for the internalization (flip) of fluorescent, 7-nitrobenz-2-oxa-1,3-diazol-4-yl(NBD)-labeled phospholipids across the plasma membrane of Saccharomyces cerevisiae. In the current study, we have demonstrated that ATP hydrolysis is not sufficient for phospholipid flip in the absence of the proton electrochemical gradient across the plasma membrane. This requirement was demonstrated by two independent means. First, collapse of the plasma membrane proton electrochemical gradient by the protonophore, carbonyl cyanide m-chlorophenylhydrazone (CCCP) almost completely blocked NBD-phospholipid flip while only moderately reducing the cytosolic ATP concentration. Second, strains with point mutations in PMA1, which encodes the plasma membrane proton pump that generates the proton electrochemical gradient, are defective in NBD-PC flip, whereas their cytosolic ATP content is actually increased. These results establish that the proton electrochemical gradient is required for NBD-phospholipid flip across the plasma membrane of yeast and raise the question whether it contributes an additional required driving force or whether it functions as a regulatory signal.

Received for publication, January 16, 2007 , and in revised form, April 5, 2007.

^* This work was supported by National Institutes of Health Grant GM64770 and, in part, by the University Research Committee of Emory University. 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 To whom correspondence should be addressed: Dept. of Physiology, Emory University School of Medicine, 615 Michael St., 605G Whitehead, Atlanta, GA 30322. Tel.: 404-727-7422; Fax: 404-727-2648; E-mail: wylie.nichols{at}emory.edu.

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

This article has been cited by other articles:

				L. Maresova, S. Muend, Y.-Q. Zhang, H. Sychrova, and R. Rao Membrane Hyperpolarization Drives Cation Influx and Fungicidal Activity of Amiodarone J. Biol. Chem., January 30, 2009; 284(5): 2795 - 2802. [Abstract] [Full Text] [PDF]

				H. C. Stevens, L. Malone, and J. W. Nichols The Putative Aminophospholipid Translocases, DNF1 and DNF2, Are Not Required for 7-Nitrobenz-2-oxa-1,3-diazol-4-yl-phosphatidylserine Flip across the Plasma Membrane of Saccharomyces cerevisiae J. Biol. Chem., December 12, 2008; 283(50): 35060 - 35069. [Abstract] [Full Text] [PDF]

				M. M. Monick, L. S. Powers, C. W. Barrett, S. Hinde, A. Ashare, D. J. Groskreutz, T. Nyunoya, M. Coleman, D. R. Spitz, and G. W. Hunninghake Constitutive ERK MAPK Activity Regulates Macrophage ATP Production and Mitochondrial Integrity J. Immunol., June 1, 2008; 180(11): 7485 - 7496. [Abstract] [Full Text] [PDF]