The membrane-bound O-acyltransferase Ale1 transfers an acyl moiety to newly synthesized 2-alkyl-sn-glycero-3-phosphocholine in yeast.

To elucidate the mechanism of acyl chain remodeling at the sn-1 position of phosphatidylcholine (PC), we investigated acyl chain introduction using a newly synthesized 1-hydroxy-2-hexadecyl-sn-glycero-3-phosphocholine (HHPC) in Saccharomyces cerevisiae. HHPC is incorporated into yeast cells and converted to a PC species containing acyl residues of 16 or 18 carbons. The efficiency of palmitoleic acid introduction to HHPCin vitro is lower in the reaction with the extract from the deletion mutant of ALE1, which encodes a membrane-bound O-acyltransferase, than in that with extracts from the wild-type strain. In addition, deletion of ALE1 causes reductions in the molecular species containing acyl residues in HHPC. These results reveal that ALE1 is involved in acyl chain transfer to the sn-1 position of HHPC in yeast.