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

This Article Full Text Full Text (PDF) 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 Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Guo, Z. Articles by Sturley, S. L. Search for Related Content PubMed PubMed Citation Articles by Guo, Z. Articles by Sturley, S. L. Social Bookmarking                      What's this?

Journal of Lipid Research, Vol. 42, 1282-1291, August 2001
Copyright © 2001 by Lipid Research, Inc.

Original Article

Identification of potential substrate-binding sites in yeast and human acyl-CoA sterol acyltransferases by mutagenesis of conserved sequences

Correspondence to: Stephen L. Sturley, To whom correspondence should be addressed., sls37{at}columbia.edu (E-mail)

In mammals, the esterification of sterols by ACAT plays a critical role in eukaryotic lipid homeostasis. Using the predominant isoform of the yeast ACAT-related enzyme family, Are2p, as a model, we targeted phylogenetically conserved sequences for mutagenesis in order to identify functionally important motifs. Deletion, truncation, and missense mutations implicate a regulatory role for the amino-terminal domain of Are2p and identified two carboxyl-terminal motifs as required for catalytic activity. A serine-to-leucine mutation in the (H/Y)SF motif (residues 338;–340), unique to sterol esterification enzymes, nullified the activity and stability of yeast Are2p. Similarly, a tyrosine-to-alanine change in the FYxDWWN motif of Are2p (residues 523;–529) produced an enzyme with decreased activity and apparent affinity for oleoyl-CoA. Mutagenesis of the tryptophan residues in this motif completely abolished activity. In human ACAT1, mutagenesis of the corresponding motifs (residues 268;–270, and 403;–409, respectively) also nullified enzymatic activity.

On the basis of their critical roles in enzymatic activity and their sequence conservation, we propose that these motifs mediate sterol and acyl-CoA binding by this class of enzymes. — Guo, Z., D. Cromley, J. T. Billheimer, and S. L. Sturley. Identification of potential substrate-binding sites in yeast and human acyl-CoA sterol acyltransferases by mutagenesis of conserved sequences. J. Lipid Res. 2001. 42: 1282;–1291.

Supplementary key words: ACAT cholesterol, steryl ester

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

This article has been cited by other articles:

				T.-Y. Chang, B.-L. Li, C. C. Y. Chang, and Y. Urano Acyl-coenzyme A:cholesterol acyltransferases Am J Physiol Endocrinol Metab, July 1, 2009; 297(1): E1 - E9. [Abstract] [Full Text] [PDF]

				C.-L. E. Yen, S. J. Stone, S. Koliwad, C. Harris, and R. V. Farese Jr. Thematic Review Series: Glycerolipids. DGAT enzymes and triacylglycerol biosynthesis J. Lipid Res., November 1, 2008; 49(11): 2283 - 2301. [Abstract] [Full Text] [PDF]

				Q. Chen, L. Steinhauer, J. Hammerlindl, W. Keller, and J. Zou Biosynthesis of Phytosterol Esters: Identification of a Sterol O-Acyltransferase in Arabidopsis Plant Physiology, November 1, 2007; 145(3): 974 - 984. [Abstract] [Full Text] [PDF]

				K. Malathi, K. Higaki, A. H. Tinkelenberg, D. A. Balderes, D. Almanzar-Paramio, L. J. Wilcox, N. Erdeniz, F. Redican, M. Padamsee, Y. Liu, et al. Mutagenesis of the putative sterol-sensing domain of yeast Niemann Pick C-related protein reveals a primordial role in subcellular sphingolipid distribution J. Cell Biol., February 16, 2004; 164(4): 547 - 556. [Abstract] [Full Text] [PDF]

				S. Lin, X. Lu, C. C.Y. Chang, and T.-Y. Chang Human Acyl-Coenzyme A:Cholesterol Acyltransferase Expressed in Chinese Hamster Ovary Cells: Membrane Topology and Active Site Location Mol. Biol. Cell, June 1, 2003; 14(6): 2447 - 2460. [Abstract] [Full Text] [PDF]

				X. Lu, S. Lin, C. C. Y. Chang, and T.-Y. Chang Mutant Acyl-coenzyme A:Cholesterol Acyltransferase 1 Devoid of Cysteine Residues Remains Catalytically Active J. Biol. Chem., January 4, 2002; 277(1): 711 - 718. [Abstract] [Full Text]

				T. Y. Chang, C. C. Y. Chang, X. Lu, and S. Lin Catalysis of ACAT may be completed within the plane of the membrane: a working hypothesis J. Lipid Res., December 1, 2001; 42(12): 1933 - 1938. [Abstract] [Full Text] [PDF]