cDNA cloning and characterization of human and mouse Ca-independent phosphatidylethanolamine N-acyltransferases |
| |
Authors: | Xing-Hua Jin Toru Uyama Jun Wang Yasuo Okamoto Takeharu Tonai Natsuo Ueda |
| |
Institution: | 1. Department of Biochemistry, Kagawa University School of Medicine, 1750-1 Ikenobe, Miki, Kagawa 761-0793, Japan;2. Department of Chemistry, Qiqihar Medical University, Qiqihar 161006, China;3. Department of Anesthesiology, The First Affiliated Hospital, China Medical University, Shenyang 110001, China;4. Department of Physiology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa 920-8640, Japan;5. Department of Orthopedic Surgery and Clinical Research Institute, National Zentsuji Hospital, Zentsuji, Kagawa 765-0001, Japan |
| |
Abstract: | The formation of N-acylphosphatidylethanolamine by N-acylation of phosphatidylethanolamine (PE) is the initial step in the biosynthetic pathway of bioactive N-acylethanolamines, including the endocannabinoid anandamide and the anti-inflammatory substance N-palmitoylethanolamine. We recently cloned a rat enzyme capable of catalyzing this reaction, and referred to the enzyme as Ca2+-independent N-acyltransferase (iNAT). Here we report cDNA cloning and characterization of human and mouse iNATs. We cloned iNAT-homologous cDNAs from human and mouse testes, and overexpressed them in COS-7 cells. The purified recombinant proteins abstracted an acyl group from both sn-1 and sn-2 positions of phosphatidylcholine, and catalyzed N-acylation of PE as well as phospholipase A1/A2-like hydrolysis. The iNAT activity was mainly detected in soluble rather than particulate fractions, and was only slightly increased by Ca2+. These results demonstrated that the human and mouse homologues function as iNAT. As for the organ distribution of iNAT, human testis and pancreas and mouse testis exhibited by far the highest expression level, suggesting its physiological importance in the specific organs. Moreover, mutagenesis studies showed crucial roles of His-154 and Cys-241 of rat iNAT in the catalysis and a possible role of the N-terminal domain in membrane association or protein–protein interaction. |
| |
Keywords: | N-acylethanolamine N-acylphosphatidylethanolamine Anandamide Phospholipase A1/A2 Phospholipid |
本文献已被 ScienceDirect 等数据库收录! |
|