National Natural Science Foundation of China (NSFC)
82072468
中国
National Natural Science Foundation of China (NSFC)
82272519
中国
引用
ジャーナル: Nat Struct Mol Biol / 年: 2024 タイトル: Cryo-EM structure of human sphingomyelin synthase and its mechanistic implications for sphingomyelin synthesis. 著者: Kexin Hu / Qing Zhang / Yang Chen / Jintong Yang / Ying Xia / Bing Rao / Shaobai Li / Yafeng Shen / Mi Cao / Hongliang Lu / An Qin / Xian-Cheng Jiang / Deqiang Yao / Jie Zhao / Lu Zhou / Yu Cao / 要旨: Sphingomyelin (SM) has key roles in modulating mammalian membrane properties and serves as an important pool for bioactive molecules. SM biosynthesis is mediated by the sphingomyelin synthase (SMS) ...Sphingomyelin (SM) has key roles in modulating mammalian membrane properties and serves as an important pool for bioactive molecules. SM biosynthesis is mediated by the sphingomyelin synthase (SMS) family, comprising SMS1, SMS2 and SMS-related (SMSr) members. Although SMS1 and SMS2 exhibit SMS activity, SMSr possesses ceramide phosphoethanolamine synthase activity. Here we determined the cryo-electron microscopic structures of human SMSr in complexes with ceramide, diacylglycerol/phosphoethanolamine and ceramide/phosphoethanolamine (CPE). The structures revealed a hexameric arrangement with a reaction chamber located between the transmembrane helices. Within this structure, a catalytic pentad E-H/D-H-D was identified, situated at the interface between the lipophilic and hydrophilic segments of the reaction chamber. Additionally, the study unveiled the two-step synthesis process catalyzed by SMSr, involving PE-PLC (phosphatidylethanolamine-phospholipase C) hydrolysis and the subsequent transfer of the phosphoethanolamine moiety to ceramide. This research provides insights into the catalytic mechanism of SMSr and expands our understanding of sphingolipid metabolism.