Lesley A Everett, Zesen Lin, Ann Friedman, Vi T Tang, Greggory Myers, Ginette Balbin-Cuesta, Richard King, Guojing Zhu, Beth McGee, Rami Khoriaty
{"title":"LMAN1 是血小板生成素的货物受体。","authors":"Lesley A Everett, Zesen Lin, Ann Friedman, Vi T Tang, Greggory Myers, Ginette Balbin-Cuesta, Richard King, Guojing Zhu, Beth McGee, Rami Khoriaty","doi":"10.1172/jci.insight.175704","DOIUrl":null,"url":null,"abstract":"<p><p>Thrombopoietin (TPO) is a plasma glycoprotein that binds its receptor on megakaryocytes (MK) and MK progenitors, resulting in enhanced platelet production. The mechanism by which TPO is secreted from hepatocytes remains poorly understood. LMAN1 and MCFD2 form a complex at the endoplasmic reticulum membrane, recruiting cargo proteins into COPII vesicles for secretion. In this study, we showed that LMAN1 deficient mice (with complete germline LMAN1 deficiency) exhibited mild thrombocytopenia, whereas the platelet count was entirely normal in mice with approximately 7% Lman1 expression. Surprisingly, mice deleted for Mcfd2 did not exhibit thrombocytopenia. Analysis of peripheral blood from LMAN1 deficient mice demonstrated normal platelet size and normal morphology of dense and alpha granules. LMAN1 deficient mice exhibited a trend toward reduced MK and MK progenitors in the bone marrow. We next showed that hepatocyte-specific but not hematopoietic Lman1 deletion results in thrombocytopenia, with plasma TPO level reduced in LMAN1 deficient mice, despite normal Tpo mRNA levels in LMAN1 deficient livers. TPO and LMAN1 interacted by co-immunoprecipitation in a heterologous cell line and TPO accumulated intracellularly in LMAN1 deleted cells. Altogether, these studies confirmed the hepatocyte as the cell of origin for TPO production in vivo and were consistent with LMAN1 as the endoplasmic reticulum cargo receptor that mediates the efficient secretion of TPO. To our knowledge, TPO is the first example of an LMAN1-dependent cargo that is independent of MCFD2.</p>","PeriodicalId":14722,"journal":{"name":"JCI insight","volume":" ","pages":""},"PeriodicalIF":6.3000,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"LMAN1 serves as a cargo receptor for thrombopoietin.\",\"authors\":\"Lesley A Everett, Zesen Lin, Ann Friedman, Vi T Tang, Greggory Myers, Ginette Balbin-Cuesta, Richard King, Guojing Zhu, Beth McGee, Rami Khoriaty\",\"doi\":\"10.1172/jci.insight.175704\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>Thrombopoietin (TPO) is a plasma glycoprotein that binds its receptor on megakaryocytes (MK) and MK progenitors, resulting in enhanced platelet production. The mechanism by which TPO is secreted from hepatocytes remains poorly understood. LMAN1 and MCFD2 form a complex at the endoplasmic reticulum membrane, recruiting cargo proteins into COPII vesicles for secretion. In this study, we showed that LMAN1 deficient mice (with complete germline LMAN1 deficiency) exhibited mild thrombocytopenia, whereas the platelet count was entirely normal in mice with approximately 7% Lman1 expression. Surprisingly, mice deleted for Mcfd2 did not exhibit thrombocytopenia. Analysis of peripheral blood from LMAN1 deficient mice demonstrated normal platelet size and normal morphology of dense and alpha granules. LMAN1 deficient mice exhibited a trend toward reduced MK and MK progenitors in the bone marrow. We next showed that hepatocyte-specific but not hematopoietic Lman1 deletion results in thrombocytopenia, with plasma TPO level reduced in LMAN1 deficient mice, despite normal Tpo mRNA levels in LMAN1 deficient livers. TPO and LMAN1 interacted by co-immunoprecipitation in a heterologous cell line and TPO accumulated intracellularly in LMAN1 deleted cells. Altogether, these studies confirmed the hepatocyte as the cell of origin for TPO production in vivo and were consistent with LMAN1 as the endoplasmic reticulum cargo receptor that mediates the efficient secretion of TPO. To our knowledge, TPO is the first example of an LMAN1-dependent cargo that is independent of MCFD2.</p>\",\"PeriodicalId\":14722,\"journal\":{\"name\":\"JCI insight\",\"volume\":\" \",\"pages\":\"\"},\"PeriodicalIF\":6.3000,\"publicationDate\":\"2024-11-05\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"JCI insight\",\"FirstCategoryId\":\"3\",\"ListUrlMain\":\"https://doi.org/10.1172/jci.insight.175704\",\"RegionNum\":1,\"RegionCategory\":\"医学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"MEDICINE, RESEARCH & EXPERIMENTAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"JCI insight","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1172/jci.insight.175704","RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MEDICINE, RESEARCH & EXPERIMENTAL","Score":null,"Total":0}
LMAN1 serves as a cargo receptor for thrombopoietin.
Thrombopoietin (TPO) is a plasma glycoprotein that binds its receptor on megakaryocytes (MK) and MK progenitors, resulting in enhanced platelet production. The mechanism by which TPO is secreted from hepatocytes remains poorly understood. LMAN1 and MCFD2 form a complex at the endoplasmic reticulum membrane, recruiting cargo proteins into COPII vesicles for secretion. In this study, we showed that LMAN1 deficient mice (with complete germline LMAN1 deficiency) exhibited mild thrombocytopenia, whereas the platelet count was entirely normal in mice with approximately 7% Lman1 expression. Surprisingly, mice deleted for Mcfd2 did not exhibit thrombocytopenia. Analysis of peripheral blood from LMAN1 deficient mice demonstrated normal platelet size and normal morphology of dense and alpha granules. LMAN1 deficient mice exhibited a trend toward reduced MK and MK progenitors in the bone marrow. We next showed that hepatocyte-specific but not hematopoietic Lman1 deletion results in thrombocytopenia, with plasma TPO level reduced in LMAN1 deficient mice, despite normal Tpo mRNA levels in LMAN1 deficient livers. TPO and LMAN1 interacted by co-immunoprecipitation in a heterologous cell line and TPO accumulated intracellularly in LMAN1 deleted cells. Altogether, these studies confirmed the hepatocyte as the cell of origin for TPO production in vivo and were consistent with LMAN1 as the endoplasmic reticulum cargo receptor that mediates the efficient secretion of TPO. To our knowledge, TPO is the first example of an LMAN1-dependent cargo that is independent of MCFD2.
期刊介绍:
JCI Insight is a Gold Open Access journal with a 2022 Impact Factor of 8.0. It publishes high-quality studies in various biomedical specialties, such as autoimmunity, gastroenterology, immunology, metabolism, nephrology, neuroscience, oncology, pulmonology, and vascular biology. The journal focuses on clinically relevant basic and translational research that contributes to the understanding of disease biology and treatment. JCI Insight is self-published by the American Society for Clinical Investigation (ASCI), a nonprofit honor organization of physician-scientists founded in 1908, and it helps fulfill the ASCI's mission to advance medical science through the publication of clinically relevant research reports.