TY - JOUR
T1 - Synthesis of oxidized phospholipids by sn-1 acyltransferase using 2–15-HETE lysophospholipids
AU - Liu, Gao Yuan
AU - Moon, Sung Ho
AU - Jenkins, Christopher M.
AU - Sims, Harold F.
AU - Guan, Shaoping
AU - Gross, Richard W.
N1 - Publisher Copyright:
© 2019 Liu et al. Published under exclusive license by The American Society for Biochemistry and Molecular Biology, Inc.
PY - 2019/6/28
Y1 - 2019/6/28
N2 - Recently, oxidized phospholipid species have emerged as important signaling lipids in activated immune cells and platelets. The canonical pathway for the synthesis of oxidized phospholipids is through the release of arachidonic acid by cytosolic phospholipase A2 (cPLA2) followed by its enzymatic oxidation, activation of the carboxylate anion by acyl-CoA synthetase(s), and re-esterification to the sn-2 position by sn-2 acyltransferase activity (i.e. the Lands cycle). However, recent studies have demonstrated the unanticipated significance of sn-1 hydrolysis of arachidonoyl-containing choline and ethanolamine glycerophospholipids by other phospholipases to generate the corresponding 2-arachidonoyl-lysolipids. Herein, we identified a pathway for oxidized phospholipid synthesis comprising sequential sn-1 hydrolysis by a phospholipase A1 (e.g. by patatin-like phospholipase domain– containing 8 (PNPLA8)), direct enzymatic oxidation of the resultant 2-arachidonoyl-lysophos-pholipids, and the esterification of oxidized 2-arachidonoyl-lysophospholipids by acyl-CoA– dependent sn-1 acyltransferase(s). To circumvent ambiguities associated with acyl migration or hydrolysis, we developed a synthesis for optically active (D- and L-enantiomers) nonhydrolyzable analogs of 2-arachidonoyl-lysophosphatidylcholine (2-AA-LPC). sn-1 acyltransferase activity in murine liver microsomes stereospe-cifically and preferentially utilized the naturally occurring L-enantiomer of the ether analog of lysophosphatidylcholine. Next, we demonstrated the high selectivity of the sn-1 acyltransferase activity for saturated acyl-CoA species. Importantly, we established that 2–15-hydroxyeicosatetraenoic acid (HETE) ether-LPC sn-1 esterification is markedly activated by thrombin treatment of murine platelets to generate oxidized PC. Collectively, these findings demonstrate the enantiomeric specificity and saturated acyl-CoA selectivity of microsomal sn-1 acyltransferase(s) and reveal its participation in a previously uncharacterized pathway for the synthesis of oxidized phospholipids with cell-signaling properties.
AB - Recently, oxidized phospholipid species have emerged as important signaling lipids in activated immune cells and platelets. The canonical pathway for the synthesis of oxidized phospholipids is through the release of arachidonic acid by cytosolic phospholipase A2 (cPLA2) followed by its enzymatic oxidation, activation of the carboxylate anion by acyl-CoA synthetase(s), and re-esterification to the sn-2 position by sn-2 acyltransferase activity (i.e. the Lands cycle). However, recent studies have demonstrated the unanticipated significance of sn-1 hydrolysis of arachidonoyl-containing choline and ethanolamine glycerophospholipids by other phospholipases to generate the corresponding 2-arachidonoyl-lysolipids. Herein, we identified a pathway for oxidized phospholipid synthesis comprising sequential sn-1 hydrolysis by a phospholipase A1 (e.g. by patatin-like phospholipase domain– containing 8 (PNPLA8)), direct enzymatic oxidation of the resultant 2-arachidonoyl-lysophos-pholipids, and the esterification of oxidized 2-arachidonoyl-lysophospholipids by acyl-CoA– dependent sn-1 acyltransferase(s). To circumvent ambiguities associated with acyl migration or hydrolysis, we developed a synthesis for optically active (D- and L-enantiomers) nonhydrolyzable analogs of 2-arachidonoyl-lysophosphatidylcholine (2-AA-LPC). sn-1 acyltransferase activity in murine liver microsomes stereospe-cifically and preferentially utilized the naturally occurring L-enantiomer of the ether analog of lysophosphatidylcholine. Next, we demonstrated the high selectivity of the sn-1 acyltransferase activity for saturated acyl-CoA species. Importantly, we established that 2–15-hydroxyeicosatetraenoic acid (HETE) ether-LPC sn-1 esterification is markedly activated by thrombin treatment of murine platelets to generate oxidized PC. Collectively, these findings demonstrate the enantiomeric specificity and saturated acyl-CoA selectivity of microsomal sn-1 acyltransferase(s) and reveal its participation in a previously uncharacterized pathway for the synthesis of oxidized phospholipids with cell-signaling properties.
UR - http://www.scopus.com/inward/record.url?scp=85068621898&partnerID=8YFLogxK
U2 - 10.1074/jbc.RA119.008766
DO - 10.1074/jbc.RA119.008766
M3 - Article
C2 - 31080170
AN - SCOPUS:85068621898
SN - 0021-9258
VL - 294
SP - 10146
EP - 10159
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 26
ER -