%0 Journal Article
%T Phosphatidylcholine formation by LPCAT1 is regulated by Ca2+ and the redox status of the cell
%A Eric Soupene
%A Frans A Kuypers
%J BMC Biochemistry
%D 2012
%I BioMed Central
%R 10.1186/1471-2091-13-8
%X Activity of LPCAT1 is inhibited by Ca2+, and a Ca2+-binding motif of the EF-hand type, EFh-1, was identified in the carboxyl-terminal domain of the protein. The residues Asp-392 and Glu-403 define the loop of the hairpin structure formed by EFh-1. Substitution of D392 and E403 to alanine rendered an enzyme insensitive to Ca2+, which established that Ca2+ binding to that region negatively regulates the activity of the acyltransferase amino-terminal domain. Residue Cys-211 of the conserved motif III is not essential for catalysis and not sufficient for sensitivity to treatment by sulfhydryl-modifier agents. Among the several active cysteine-substitution mutants of LPCAT1 generated, we identified one to be resistant to treatment by sulfhydryl-alkylating and sulfhydryl-oxidizer agents.Mutant forms of LPCAT1 that are not inhibited by Ca2+ and sulfhydryl-alkylating and ¨Coxidizing agents will provide a better understanding of the physiological function of a mechanism that places the formation of PC, and the disposal of the bioactive species lysoPC, under the control of the redox status and Ca2+ concentration of the cell.
%K Lands¡¯ cycle
%K Cysteine oxidation
%K Calcium binding
%K Plasma membrane
%U http://www.biomedcentral.com/1471-2091/13/8/abstract