Phosphatidylserine-stimulated production of N-acyl-phosphatidylethanolamines by Ca2+-dependent N-acyltransferase.
Biochim Biophys Acta Mol Cell Biol Lipids
; 1863(5): 493-502, 2018 May.
Article
em En
| MEDLINE
| ID: mdl-29447909
ABSTRACT
N-acyl-phosphatidylethanolamine (NAPE) is known to be a precursor for various bioactive N-acylethanolamines including the endocannabinoid anandamide. NAPE is produced in mammals through the transfer of an acyl chain from certain glycerophospholipids to phosphatidylethanolamine (PE) by Ca2+-dependent or -independent N-acyltransferases. The ε isoform of mouse cytosolic phospholipase A2 (cPLA2ε) was recently identified as a Ca2+-dependent N-acyltransferase (Ca-NAT). In the present study, we first showed that two isoforms of human cPLA2ε function as Ca-NAT. We next purified both mouse recombinant cPLA2ε and its two human orthologues to examine their catalytic properties. The enzyme absolutely required Ca2+ for its activity and the activity was enhanced by phosphatidylserine (PS). PS enhanced the activity 25-fold in the presence of 1â¯mM CaCl2 and lowered the EC50 value of Ca2+ >8-fold. Using a PS probe, we showed that cPLA2ε largely co-localizes with PS in plasma membrane and organelles involved in the endocytic pathway, further supporting the interaction of cPLA2ε with PS in living cells. Finally, we found that the Ca2+-ionophore ionomycin increased [14C]NAPE levels >10-fold in [14C]ethanolamine-labeled cPLA2ε-expressing cells while phospholipase A/acyltransferase-1, acting as a Ca2+-independent N-acyltransferase, was insensitive to ionomycin for full activity. In conclusion, PS potently stimulated the Ca2+-dependent activity and human cPLA2ε isoforms also functioned as Ca-NAT.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fosfatidiletanolaminas
/
Fosfatidilserinas
/
Aciltransferases
/
Cálcio
Tipo de estudo:
Prognostic_studies
Limite:
Animals
/
Humans
Idioma:
En
Revista:
Biochim Biophys Acta Mol Cell Biol Lipids
Ano de publicação:
2018
Tipo de documento:
Article
País de afiliação:
Japão