Vasiliki Lalioti, Galina V Beznoussenko, Alexander A Mironov, Ignacio V Sandoval
{"title":"E-Syt3的分裂和转运揭示了原始池,这是一种新的细胞器,在脂肪细胞中产生脂滴。","authors":"Vasiliki Lalioti, Galina V Beznoussenko, Alexander A Mironov, Ignacio V Sandoval","doi":"10.1111/tra.12823","DOIUrl":null,"url":null,"abstract":"<p><p>Extended synaptotagmins are endoplasmic reticulum proteins consisting of an SMP domain and multiple C2 domains that bind phospholipids and Ca<sup>2+</sup> . E-Syts create contact junctions between the ER and plasma membrane (PM) to facilitate the exchange of glycerophospholipids between the apposed membranes. We find in the differentiating adipocyte that the E-Syt3 carboxyl domain is cleaved by a multi-step mechanism that includes removing the C2C domain. Confocal and live-cell time-lapse studies show that truncated E-Syt3ΔC2C, as well as endogenous E-Syt3 and the coat protein PLIN1, target the LDs from an annular, single giant ER cisterna. Inhibition of the proteasome blocks the proteolytic cleavage of Esyt3 and E-Syt3ΔC2C and causes the E-Syt3ΔC2C retention in the giant cisterna. The Esyt3 and PLIN1 distributions and LDs biogenesis show that the primordial cisterna, as we call it, is the birth and nurturing site of LDs in the adipocyte. Isoproterenol-induced lipolysis results in loss of cytoplasmic LDs and reappearance of the primordial cisterna. Electron microscopy and 3D-electron tomography studies show that the primordial cisterna consists of a tightly packed network of varicose tubules with extensively blistered membranes. Rounds of homotypic fusions from nascent to mature LDs play a central role in LD growth. The knockdown of E-Syt3 inhibits LD biogenesis. The identification of the primordial cisterna, an organelle that substitutes the randomly scattered ER foci that mother the LDs in non-adipose cells, sets the stage for a better understanding of LD biogenesis in the adipocyte.</p>","PeriodicalId":23207,"journal":{"name":"Traffic","volume":null,"pages":null},"PeriodicalIF":3.6000,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"3","resultStr":"{\"title\":\"The E-Syt3 cleavage and traffic uncovers the primordial cisterna, a new organelle that mothers the lipid droplets in the adipocyte.\",\"authors\":\"Vasiliki Lalioti, Galina V Beznoussenko, Alexander A Mironov, Ignacio V Sandoval\",\"doi\":\"10.1111/tra.12823\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>Extended synaptotagmins are endoplasmic reticulum proteins consisting of an SMP domain and multiple C2 domains that bind phospholipids and Ca<sup>2+</sup> . E-Syts create contact junctions between the ER and plasma membrane (PM) to facilitate the exchange of glycerophospholipids between the apposed membranes. We find in the differentiating adipocyte that the E-Syt3 carboxyl domain is cleaved by a multi-step mechanism that includes removing the C2C domain. Confocal and live-cell time-lapse studies show that truncated E-Syt3ΔC2C, as well as endogenous E-Syt3 and the coat protein PLIN1, target the LDs from an annular, single giant ER cisterna. Inhibition of the proteasome blocks the proteolytic cleavage of Esyt3 and E-Syt3ΔC2C and causes the E-Syt3ΔC2C retention in the giant cisterna. The Esyt3 and PLIN1 distributions and LDs biogenesis show that the primordial cisterna, as we call it, is the birth and nurturing site of LDs in the adipocyte. Isoproterenol-induced lipolysis results in loss of cytoplasmic LDs and reappearance of the primordial cisterna. Electron microscopy and 3D-electron tomography studies show that the primordial cisterna consists of a tightly packed network of varicose tubules with extensively blistered membranes. Rounds of homotypic fusions from nascent to mature LDs play a central role in LD growth. The knockdown of E-Syt3 inhibits LD biogenesis. The identification of the primordial cisterna, an organelle that substitutes the randomly scattered ER foci that mother the LDs in non-adipose cells, sets the stage for a better understanding of LD biogenesis in the adipocyte.</p>\",\"PeriodicalId\":23207,\"journal\":{\"name\":\"Traffic\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":3.6000,\"publicationDate\":\"2022-01-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"3\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Traffic\",\"FirstCategoryId\":\"99\",\"ListUrlMain\":\"https://doi.org/10.1111/tra.12823\",\"RegionNum\":3,\"RegionCategory\":\"生物学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"2021/11/10 0:00:00\",\"PubModel\":\"Epub\",\"JCR\":\"Q3\",\"JCRName\":\"CELL BIOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Traffic","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1111/tra.12823","RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2021/11/10 0:00:00","PubModel":"Epub","JCR":"Q3","JCRName":"CELL BIOLOGY","Score":null,"Total":0}
The E-Syt3 cleavage and traffic uncovers the primordial cisterna, a new organelle that mothers the lipid droplets in the adipocyte.
Extended synaptotagmins are endoplasmic reticulum proteins consisting of an SMP domain and multiple C2 domains that bind phospholipids and Ca2+ . E-Syts create contact junctions between the ER and plasma membrane (PM) to facilitate the exchange of glycerophospholipids between the apposed membranes. We find in the differentiating adipocyte that the E-Syt3 carboxyl domain is cleaved by a multi-step mechanism that includes removing the C2C domain. Confocal and live-cell time-lapse studies show that truncated E-Syt3ΔC2C, as well as endogenous E-Syt3 and the coat protein PLIN1, target the LDs from an annular, single giant ER cisterna. Inhibition of the proteasome blocks the proteolytic cleavage of Esyt3 and E-Syt3ΔC2C and causes the E-Syt3ΔC2C retention in the giant cisterna. The Esyt3 and PLIN1 distributions and LDs biogenesis show that the primordial cisterna, as we call it, is the birth and nurturing site of LDs in the adipocyte. Isoproterenol-induced lipolysis results in loss of cytoplasmic LDs and reappearance of the primordial cisterna. Electron microscopy and 3D-electron tomography studies show that the primordial cisterna consists of a tightly packed network of varicose tubules with extensively blistered membranes. Rounds of homotypic fusions from nascent to mature LDs play a central role in LD growth. The knockdown of E-Syt3 inhibits LD biogenesis. The identification of the primordial cisterna, an organelle that substitutes the randomly scattered ER foci that mother the LDs in non-adipose cells, sets the stage for a better understanding of LD biogenesis in the adipocyte.
期刊介绍:
Traffic encourages and facilitates the publication of papers in any field relating to intracellular transport in health and disease. Traffic papers span disciplines such as developmental biology, neuroscience, innate and adaptive immunity, epithelial cell biology, intracellular pathogens and host-pathogen interactions, among others using any eukaryotic model system. Areas of particular interest include protein, nucleic acid and lipid traffic, molecular motors, intracellular pathogens, intracellular proteolysis, nuclear import and export, cytokinesis and the cell cycle, the interface between signaling and trafficking or localization, protein translocation, the cell biology of adaptive an innate immunity, organelle biogenesis, metabolism, cell polarity and organization, and organelle movement.
All aspects of the structural, molecular biology, biochemistry, genetics, morphology, intracellular signaling and relationship to hereditary or infectious diseases will be covered. Manuscripts must provide a clear conceptual or mechanistic advance. The editors will reject papers that require major changes, including addition of significant experimental data or other significant revision.
Traffic will consider manuscripts of any length, but encourages authors to limit their papers to 16 typeset pages or less.