Identification of a novel GPCAT activity and a new pathway for phosphatidylcholine biosynthesis in S. cerevisiae

Turnover of phospholipids in the yeast Saccharomyces cerevisiae generates intracellular glycerophosphocholine (GPC). Here we show that GPC can be reacylated in an acyl-CoA-dependent reaction by yeast microsomal membranes. The lysophosphatidylcholine that is formed in this reaction is efficiently fur...

Full description

Saved in:
Bibliographic Details
Published in:Journal of lipid research 2008-08, Vol.49 (8), p.1794-1806
Main Authors: Stålberg, Kjell, Neal, Andrea C., Ronne, Hans, Ståhl, Ulf
Format: Article
Language:English
Subjects:
1-Acylglycerophosphocholine O-Acyltransferase - isolation & purification
1-Acylglycerophosphocholine O-Acyltransferase - metabolism
Acyltransferases - isolation & purification
Acyltransferases - metabolism
Biologi
Biology
fatty acid
Glycerol-3-Phosphate O-Acyltransferase - metabolism
glycerophosphocholine acyltransferase
glycerophosphoethanolamine
Kinetics
lysophosphatidylcholine
membrane
NATURAL SCIENCES
NATURVETENSKAP
Phosphatidylcholines - biosynthesis
phosphatidylethanolamine
phospholipid
recycling
remodeling
Saccharomyces cerevisiae
Saccharomyces cerevisiae - metabolism
Saccharomyces cerevisiae Proteins - isolation & purification
Saccharomyces cerevisiae Proteins - metabolism
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Turnover of phospholipids in the yeast Saccharomyces cerevisiae generates intracellular glycerophosphocholine (GPC). Here we show that GPC can be reacylated in an acyl-CoA-dependent reaction by yeast microsomal membranes. The lysophosphatidylcholine that is formed in this reaction is efficiently further acylated to phosphatidylcholine (PC) by yeast microsomes, thus providing a new pathway for PC biosynthesis that can either recycle endogenously generated GPC or utilize externally provided GPC. Genetic and biochemical evidence suggests that this new enzymatic activity, which we call GPC acyltransferase (GPCAT), is not mediated by any of the previously known acyltransferases in yeast. The GPCAT activity has an apparent Vmax of 8.7 nmol/min/mg protein and an apparent Km of 2.5 mM. It has a neutral pH optimum, similar to yeast glycerol-3-phosphate acyltransferase, but differs from the latter in being more heat stable. The GPCAT activity is sensitive to N-ethylmaleimide, phenanthroline, and Zn2+ ions. In vivo experiments showed that PC is efficiently labeled when yeast cells are fed with [3H]choline-GPC, and that this reaction occurs also in pct1 knockout strains, where de novo synthesis of PC by the CDP-choline pathway is blocked. This suggests that GPCAT can provide an alternative pathway for PC biosynthesis in vivo.
ISSN:0022-2275
1539-7262
1539-7262
DOI:10.1194/jlr.M800129-JLR200