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
{"title":"人类鞘磷脂合成酶的低温电子显微镜结构及其对鞘磷脂合成的机理影响","authors":"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","doi":"10.1038/s41594-024-01237-2","DOIUrl":null,"url":null,"abstract":"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. Researchers unveiled the structural details of sphingomyelin synthase (SMSr), shedding light on its role in sphingolipid biosynthesis. SMSr transfers the phosphoethanolamine from PE to ceramide, adding complexity to the field of lipid homeostasis.","PeriodicalId":49141,"journal":{"name":"Nature Structural & Molecular Biology","volume":null,"pages":null},"PeriodicalIF":12.5000,"publicationDate":"2024-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Cryo-EM structure of human sphingomyelin synthase and its mechanistic implications for sphingomyelin synthesis\",\"authors\":\"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\",\"doi\":\"10.1038/s41594-024-01237-2\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"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. Researchers unveiled the structural details of sphingomyelin synthase (SMSr), shedding light on its role in sphingolipid biosynthesis. SMSr transfers the phosphoethanolamine from PE to ceramide, adding complexity to the field of lipid homeostasis.\",\"PeriodicalId\":49141,\"journal\":{\"name\":\"Nature Structural & Molecular Biology\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":12.5000,\"publicationDate\":\"2024-02-22\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Nature Structural & Molecular Biology\",\"FirstCategoryId\":\"99\",\"ListUrlMain\":\"https://www.nature.com/articles/s41594-024-01237-2\",\"RegionNum\":1,\"RegionCategory\":\"生物学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"BIOCHEMISTRY & MOLECULAR BIOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Nature Structural & Molecular Biology","FirstCategoryId":"99","ListUrlMain":"https://www.nature.com/articles/s41594-024-01237-2","RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"BIOCHEMISTRY & MOLECULAR BIOLOGY","Score":null,"Total":0}
Cryo-EM structure of human sphingomyelin synthase and its mechanistic implications for sphingomyelin synthesis
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. Researchers unveiled the structural details of sphingomyelin synthase (SMSr), shedding light on its role in sphingolipid biosynthesis. SMSr transfers the phosphoethanolamine from PE to ceramide, adding complexity to the field of lipid homeostasis.
期刊介绍:
Nature Structural & Molecular Biology is a comprehensive platform that combines structural and molecular research. Our journal focuses on exploring the functional and mechanistic aspects of biological processes, emphasizing how molecular components collaborate to achieve a particular function. While structural data can shed light on these insights, our publication does not require them as a prerequisite.