Ypr140wp, 'the yeast tafazzin', displays a mitochondrial lysophosphatidylcholine (lyso-PC) acyltransferase activity related to triacylglycerol and mitochondrial lipid synthesis.
When the yeast protein Ypr140w was expressed in Escherichia coli, a lyso-PC [lysophosphatidylcholine (1-acylglycerophosphorylcholine)] acyltransferase activity was found associated with the membranes of the bacteria. To our knowledge, this is the first identification of a protein capable of catalysing the acylation of lyso-PC molecules to form PC. Fluorescence microscopy analysis of living yeasts revealed that the fusion protein Ypr140w-green fluorescent protein is targeted to the mitochondria. Moreover, in contrast with wild-type cells, in the absence of acyl-CoA, the yeast mutant deleted for the YPR140w gene has no lyso-PC acyltransferase activity associated with the mitochondrial fraction. When yeast cells were grown in the presence of lactate, the mutant synthesized 2-fold more triacylglycerols when compared with the wild-type. Moreover, its mitochondrial membranes contained a lesser amount of PC and cardiolipin, and the fatty acid composition of these latter was greatly changed. These modifications were accompanied by a 2-fold increase in the respiration rates (states 3 and 4) of the mitochondria. The relationship between the deletion of the YPR140w gene and the lipid composition of the ypr140wDelta cells is discussed.
Testet
Eric
E
Laboratoire de Biogenèse Membranaire, UMR 5200, CNRS-Université Victor Segalen, Bordeaux 2/ESTBB, case 92, 146 rue Léo Saignat, 33076 Bordeaux Cedex, France. Eric.Testet@biomemb.u-bordeaux2.fr
Laroche-Traineau
Jeanny
J
Noubhani
Abdelmajid
A
Coulon
Denis
D
Bunoust
Odile
O
Camougrand
Nadine
N
Manon
Stephen
S
Lessire
René
R
Bessoule
Jean-Jacques
JJ
D008243:1-Acylglycerophosphocholine O-Acyltransferase / Q000378:metabolism*; D000217:Acyltransferases / Q000378:metabolism*; D000595:Amino Acid Sequence; D002462:Cell Membrane / Q000201:enzymology; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D008055:Lipids / Q000096:biosynthesis*; D008928:Mitochondria / Q000201:enzymology*; D008969:Molecular Sequence Data; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D014280:Triglycerides / Q000096:biosynthesis*
D008055:Lipids; D029701:Saccharomyces cerevisiae Proteins; D014280:Triglycerides; D000217:Acyltransferases; C481660:Taz1 protein, S cerevisiae; D008243:1-Acylglycerophosphocholine O-Acyltransferase