Pub Date : 2020-10-01DOI: 10.1177/2515256420964170
S. Cockcroft, S. Lev
Phosphatidylinositol (PI)-transfer proteins (PITPs) have been long recognized as proteins that modulate phosphoinositide levels in membranes through their intrinsic PI/PC-exchange activity. Recent studies from flies and mammals suggest that certain PITPs bind phosphatidic acid (PA) and possess PI/PA-exchange activity. Phosphoinositides and PA play critical roles in cell signaling and membrane trafficking, and numerous biochemical, genetic and functional studies have shown that PITPs regulate cellular lipid metabolism, various signaling pathways and intracellular membrane transport events. In this mini-review, we discuss the function of mammalian PITPs at the Golgi and ER-Golgi membrane contact sites (MCS) and highlight DAG (Diacylglycerol) as a central hub of PITPs functions. We describe PITPs-associated phospho-signaling network at the ER-Golgi interface, and share our perspective on future studies related to PITPs at MCSs.
{"title":"Mammalian PITPs at the Golgi and ER-Golgi Membrane Contact Sites","authors":"S. Cockcroft, S. Lev","doi":"10.1177/2515256420964170","DOIUrl":"https://doi.org/10.1177/2515256420964170","url":null,"abstract":"Phosphatidylinositol (PI)-transfer proteins (PITPs) have been long recognized as proteins that modulate phosphoinositide levels in membranes through their intrinsic PI/PC-exchange activity. Recent studies from flies and mammals suggest that certain PITPs bind phosphatidic acid (PA) and possess PI/PA-exchange activity. Phosphoinositides and PA play critical roles in cell signaling and membrane trafficking, and numerous biochemical, genetic and functional studies have shown that PITPs regulate cellular lipid metabolism, various signaling pathways and intracellular membrane transport events. In this mini-review, we discuss the function of mammalian PITPs at the Golgi and ER-Golgi membrane contact sites (MCS) and highlight DAG (Diacylglycerol) as a central hub of PITPs functions. We describe PITPs-associated phospho-signaling network at the ER-Golgi interface, and share our perspective on future studies related to PITPs at MCSs.","PeriodicalId":87951,"journal":{"name":"Contact","volume":"63 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73576868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-09-01DOI: 10.1177/2515256420934671
Zhe Cao, H. Y. Mak
The endoplasmic reticulum (ER) is a hub that coordinates neutral lipid synthesis, storage, and export. To fulfill this role, the ER maintains close contact with lipid droplets (LDs), which are evolutionarily conserved organelles for the storage of neutral lipids. Decades of biochemical evidence points to fatty acid modification and neutral lipid synthesis in the ER. Conceptually, lipid export into extracellular space or lipid retention intracellularly require the subsequent remodeling of an ER membrane leaflet that faces the lumen or cytoplasm, respectively. This is because LDs and very-low-density lipoprotein particles are all structures surrounded by a phospholipid monolayer. While the export of neutral lipids via very-low-density lipoprotein production is well characterized, there has been increasing interest in the mechanisms that underlie neutral lipid retention in LDs. Structural determination, in vitro reconstitution, and localization of key proteins by advanced microscopy techniques collectively enrich models of ER-LD engagement. In this review, we consider current concepts on how LDs emerge from the ER in a directional manner and how sustained ER-LD contacts support LD expansion.
{"title":"Married at Birth: Regulation of Cellular Fat Metabolism by ER–Lipid Droplet Crosstalk","authors":"Zhe Cao, H. Y. Mak","doi":"10.1177/2515256420934671","DOIUrl":"https://doi.org/10.1177/2515256420934671","url":null,"abstract":"The endoplasmic reticulum (ER) is a hub that coordinates neutral lipid synthesis, storage, and export. To fulfill this role, the ER maintains close contact with lipid droplets (LDs), which are evolutionarily conserved organelles for the storage of neutral lipids. Decades of biochemical evidence points to fatty acid modification and neutral lipid synthesis in the ER. Conceptually, lipid export into extracellular space or lipid retention intracellularly require the subsequent remodeling of an ER membrane leaflet that faces the lumen or cytoplasm, respectively. This is because LDs and very-low-density lipoprotein particles are all structures surrounded by a phospholipid monolayer. While the export of neutral lipids via very-low-density lipoprotein production is well characterized, there has been increasing interest in the mechanisms that underlie neutral lipid retention in LDs. Structural determination, in vitro reconstitution, and localization of key proteins by advanced microscopy techniques collectively enrich models of ER-LD engagement. In this review, we consider current concepts on how LDs emerge from the ER in a directional manner and how sustained ER-LD contacts support LD expansion.","PeriodicalId":87951,"journal":{"name":"Contact","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84377581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-09-01DOI: 10.1177/2515256420960303
Ji Seul Han, K. H. Han, J. B. Kim
Lipid droplets (LDs) are dynamic subcellular organelles which play critical roles for lipid homeostasis upon change of nutritional state. Although several organelles such as mitochondria and peroxisomes are involved in lipid metabolism, physiological roles and mediators involved in the spatiotemporal regulation of these subcellular organelles for energy metabolism has largely remained elusive. Our recent study implicates the importance of peroxisomes in the translocation of lipases onto LDs upon fasting cues. Also, we found that peroxisomal protein PEX5 modulates PKA-induced lipolysis by escorting ATGL toward LDs. This is accompanied by KIFC3-mediated migration of peroxisomes, leading to the physical contact between peroxisomes and LDs. In adipocyte-specific PEX5-knockout mice, fasting induced lipolysis is attenuated due to defective ATGL recruitment onto LDs. These results show that PEX5 plays a pivotal role in PKA induced lipolysis that occurs upon nutritional deprivation. We further speculate that the contact between LDs and peroxisomes could facilitate lipid metabolism via exchange of lipid metabolites between the organelles in response to nutritional changes.
{"title":"Peroxisomal-PEX5 Controls Fasting-Induced Lipolysis","authors":"Ji Seul Han, K. H. Han, J. B. Kim","doi":"10.1177/2515256420960303","DOIUrl":"https://doi.org/10.1177/2515256420960303","url":null,"abstract":"Lipid droplets (LDs) are dynamic subcellular organelles which play critical roles for lipid homeostasis upon change of nutritional state. Although several organelles such as mitochondria and peroxisomes are involved in lipid metabolism, physiological roles and mediators involved in the spatiotemporal regulation of these subcellular organelles for energy metabolism has largely remained elusive. Our recent study implicates the importance of peroxisomes in the translocation of lipases onto LDs upon fasting cues. Also, we found that peroxisomal protein PEX5 modulates PKA-induced lipolysis by escorting ATGL toward LDs. This is accompanied by KIFC3-mediated migration of peroxisomes, leading to the physical contact between peroxisomes and LDs. In adipocyte-specific PEX5-knockout mice, fasting induced lipolysis is attenuated due to defective ATGL recruitment onto LDs. These results show that PEX5 plays a pivotal role in PKA induced lipolysis that occurs upon nutritional deprivation. We further speculate that the contact between LDs and peroxisomes could facilitate lipid metabolism via exchange of lipid metabolites between the organelles in response to nutritional changes.","PeriodicalId":87951,"journal":{"name":"Contact","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82398853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-09-01DOI: 10.1177/2515256420945820
Veijo T. Salo, M. Hölttä-Vuori, E. Ikonen
Lipid droplets (LDs) are dynamic cellular hubs of lipid metabolism. While LDs contact a plethora of organelles, they have the most intimate relationship with the endoplasmic reticulum (ER). Indeed, LDs are initially assembled at specialized ER subdomains, and recent work has unraveled an increasing array of proteins regulating ER-LD contacts. Among these, seipin, a highly conserved lipodystrophy protein critical for LD growth and adipogenesis, deserves special attention. Here, we review recent insights into the role of seipin in LD biogenesis and as a regulator of ER-LD contacts. These studies have also highlighted the evolving concept of ER and LDs as a functional continuum for lipid partitioning and pinpointed a role for seipin at the ER-LD nexus in controlling lipid flux between these compartments.
{"title":"Seipin-Mediated Contacts as Gatekeepers of Lipid Flux at the Endoplasmic Reticulum–Lipid Droplet Nexus","authors":"Veijo T. Salo, M. Hölttä-Vuori, E. Ikonen","doi":"10.1177/2515256420945820","DOIUrl":"https://doi.org/10.1177/2515256420945820","url":null,"abstract":"Lipid droplets (LDs) are dynamic cellular hubs of lipid metabolism. While LDs contact a plethora of organelles, they have the most intimate relationship with the endoplasmic reticulum (ER). Indeed, LDs are initially assembled at specialized ER subdomains, and recent work has unraveled an increasing array of proteins regulating ER-LD contacts. Among these, seipin, a highly conserved lipodystrophy protein critical for LD growth and adipogenesis, deserves special attention. Here, we review recent insights into the role of seipin in LD biogenesis and as a regulator of ER-LD contacts. These studies have also highlighted the evolving concept of ER and LDs as a functional continuum for lipid partitioning and pinpointed a role for seipin at the ER-LD nexus in controlling lipid flux between these compartments.","PeriodicalId":87951,"journal":{"name":"Contact","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86290694","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-09-01DOI: 10.1177/2515256420956818
Y. Aw, Andrew J. Brown, Jia-Wei Wu, Hongyuan Yang
Lipid transfer proteins are crucial for intracellular cholesterol trafficking at sites of membrane contact. In the OSBP/ORPs (oxysterol binding protein and OSBP-related proteins) family of lipid transfer proteins, ORP1L, ORP1S and ORP2 play important roles in cholesterol transport. ORP1L is an endosome/lysosome-anchored cholesterol sensor which may also move cholesterol bidirectionally at the interface between the endoplasmic reticulum and the endosome/lysosome. ORP2 delivers cholesterol to the plasma membrane, driven by PI(4,5)P2 hydrolysis. ORP1S may also transport cholesterol to the plasma membrane, although it is unclear if phosphoinositides are involved. The source of cholesterol delivered to the plasma membrane by ORP1S and ORP2 remains unclear. This review summarises the roles of these proteins in maintaining cellular cholesterol homeostasis and in human disease.
{"title":"ORP1L, ORP1S, and ORP2: Lipid Sensors and Transporters","authors":"Y. Aw, Andrew J. Brown, Jia-Wei Wu, Hongyuan Yang","doi":"10.1177/2515256420956818","DOIUrl":"https://doi.org/10.1177/2515256420956818","url":null,"abstract":"Lipid transfer proteins are crucial for intracellular cholesterol trafficking at sites of membrane contact. In the OSBP/ORPs (oxysterol binding protein and OSBP-related proteins) family of lipid transfer proteins, ORP1L, ORP1S and ORP2 play important roles in cholesterol transport. ORP1L is an endosome/lysosome-anchored cholesterol sensor which may also move cholesterol bidirectionally at the interface between the endoplasmic reticulum and the endosome/lysosome. ORP2 delivers cholesterol to the plasma membrane, driven by PI(4,5)P2 hydrolysis. ORP1S may also transport cholesterol to the plasma membrane, although it is unclear if phosphoinositides are involved. The source of cholesterol delivered to the plasma membrane by ORP1S and ORP2 remains unclear. This review summarises the roles of these proteins in maintaining cellular cholesterol homeostasis and in human disease.","PeriodicalId":87951,"journal":{"name":"Contact","volume":"74 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72910719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-09-01DOI: 10.1177/2515256420959514
Asako Goto, Aya Mizuike, K. Hanada
Proteins and lipids represent the two major constituents of biological membranes. Different organelles have different lipid compositions, which may be crucial for the execution and control of various organelle-specific functions. The interorganellar transport of lipids is dominated by mechanisms that are distinct from the vesicular mechanisms that underlie the interorganellar transport of proteins. Lipid transfer proteins (LTPs) efficiently and accurately mediate the trafficking of membrane lipids at the interfaces between different organelles. In this review, which focuses on sphingolipids, we describe the coordinated synthesis and transfer of lipids that occur at the endoplasmic reticulum (ER)-Golgi apparatus contact zones and discuss the impacts of lipid metabolism on membrane trafficking from the trans-Golgi network (TGN).
{"title":"Sphingolipid Metabolism at the ER-Golgi Contact Zone and Its Impact on Membrane Trafficking","authors":"Asako Goto, Aya Mizuike, K. Hanada","doi":"10.1177/2515256420959514","DOIUrl":"https://doi.org/10.1177/2515256420959514","url":null,"abstract":"Proteins and lipids represent the two major constituents of biological membranes. Different organelles have different lipid compositions, which may be crucial for the execution and control of various organelle-specific functions. The interorganellar transport of lipids is dominated by mechanisms that are distinct from the vesicular mechanisms that underlie the interorganellar transport of proteins. Lipid transfer proteins (LTPs) efficiently and accurately mediate the trafficking of membrane lipids at the interfaces between different organelles. In this review, which focuses on sphingolipids, we describe the coordinated synthesis and transfer of lipids that occur at the endoplasmic reticulum (ER)-Golgi apparatus contact zones and discuss the impacts of lipid metabolism on membrane trafficking from the trans-Golgi network (TGN).","PeriodicalId":87951,"journal":{"name":"Contact","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89598403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-01DOI: 10.1177/2515256420926354
M. Hayes, Anne Zakrzewski, T. Levine, M. Telford
Symsagittifera roscoffensis is a small marine worm found in the intertidal zone of sandy beaches around the European shores of the Atlantic. S. roscoffensis is a member of the Acoelomorpha, a group of flatworms formerly classified with the Platyhelminthes, but now recognized as Xenacoelomorpha, a separate phylum of disputed affinity. We have used electron microscopy to examine the process of spermiogenesis (the final stage of spermatogenesis) in S. roscoffensis, by which spermatids form highly elongated spermatozoa. Their nuclei are long and thread-like, running most of the cell’s length, and during the process, a pair of flagella are fully incorporated into the cell body. Two previously undescribed interorganelle contact sites form at different stages of spermiogenesis. Strikingly, there is an extensive nucleus–plasma membrane contact site. Golgi-derived granules containing electron-dense filaments line up along the spermatid plasma membrane, undergo a conformational change, and donate material that forms a perinuclear layer that cements this contact site. We also show in spermatids at an earlier stage that the same granules are associated with microtubules, presumably for traffic along the elongating cell. We identify a second spermiogenesis-specific contact site where sheaths engulfing each internalizing flagellum contact the nuclear envelope.
{"title":"Nucleus–Plasma Membrane Contact Sites Are Formed During Spermiogenesis in the Acoel Symsagittifera roscoffensis","authors":"M. Hayes, Anne Zakrzewski, T. Levine, M. Telford","doi":"10.1177/2515256420926354","DOIUrl":"https://doi.org/10.1177/2515256420926354","url":null,"abstract":"Symsagittifera roscoffensis is a small marine worm found in the intertidal zone of sandy beaches around the European shores of the Atlantic. S. roscoffensis is a member of the Acoelomorpha, a group of flatworms formerly classified with the Platyhelminthes, but now recognized as Xenacoelomorpha, a separate phylum of disputed affinity. We have used electron microscopy to examine the process of spermiogenesis (the final stage of spermatogenesis) in S. roscoffensis, by which spermatids form highly elongated spermatozoa. Their nuclei are long and thread-like, running most of the cell’s length, and during the process, a pair of flagella are fully incorporated into the cell body. Two previously undescribed interorganelle contact sites form at different stages of spermiogenesis. Strikingly, there is an extensive nucleus–plasma membrane contact site. Golgi-derived granules containing electron-dense filaments line up along the spermatid plasma membrane, undergo a conformational change, and donate material that forms a perinuclear layer that cements this contact site. We also show in spermatids at an earlier stage that the same granules are associated with microtubules, presumably for traffic along the elongating cell. We identify a second spermiogenesis-specific contact site where sheaths engulfing each internalizing flagellum contact the nuclear envelope.","PeriodicalId":87951,"journal":{"name":"Contact","volume":" 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91412384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-05-01DOI: 10.1177/2515256420926795
R. Zimmermann, Sven Lang
Pioneering work in the 1990s started to address an interesting question. How is the main cellular energy source, adenosine triphosphate (ATP), imported into the mammalian endoplasmic reticulum (ER)? Despite its high-energy demand, large volume, and structural as well as functional complexity, the ER harbors no intricate system for ATP synthesis or regeneration. Although the original biochemical reconstitution approaches established hallmarks of the ATP transport into the ER including nucleotide selectivity, affinity, and antiport mode, the more recent live-cell imaging methods employing sensitive, localized molecular probes identified the elusive ATP/adenosine diphosphate (ADP) exchanger. According to its selectivity and localization, the identified SLC35B1 protein was rebranded AXER. Here, we discuss the identification and regulation of AXER plus the cytosolic partners (AMP-activated protein kinase, AMPK) and subcellular structures (mitochondrial–ER contact sites, MERCs) acting in concert with it to orchestrate energy homeostasis of the mammalian ER. Furthermore, we combine the two seemingly controversial regulatory mechanisms (lowER and CaATiER) in a unifying hypothesis.
{"title":"A Little AXER ABC: ATP, BiP, and Calcium Form a Triumvirate Orchestrating Energy Homeostasis of the Endoplasmic Reticulum","authors":"R. Zimmermann, Sven Lang","doi":"10.1177/2515256420926795","DOIUrl":"https://doi.org/10.1177/2515256420926795","url":null,"abstract":"Pioneering work in the 1990s started to address an interesting question. How is the main cellular energy source, adenosine triphosphate (ATP), imported into the mammalian endoplasmic reticulum (ER)? Despite its high-energy demand, large volume, and structural as well as functional complexity, the ER harbors no intricate system for ATP synthesis or regeneration. Although the original biochemical reconstitution approaches established hallmarks of the ATP transport into the ER including nucleotide selectivity, affinity, and antiport mode, the more recent live-cell imaging methods employing sensitive, localized molecular probes identified the elusive ATP/adenosine diphosphate (ADP) exchanger. According to its selectivity and localization, the identified SLC35B1 protein was rebranded AXER. Here, we discuss the identification and regulation of AXER plus the cytosolic partners (AMP-activated protein kinase, AMPK) and subcellular structures (mitochondrial–ER contact sites, MERCs) acting in concert with it to orchestrate energy homeostasis of the mammalian ER. Furthermore, we combine the two seemingly controversial regulatory mechanisms (lowER and CaATiER) in a unifying hypothesis.","PeriodicalId":87951,"journal":{"name":"Contact","volume":"58 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85382828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-03-01DOI: 10.1177/2515256420908142
Maria Bohnert
Lipid droplets (LDs) are central hubs in cellular lipid handling. They serve as lipid storage organelles and are involved in neutral lipid biosynthesis and breakdown as well as in the production of phospholipids and sterols. For communication with other organelles, LDs are heavily engaged in contact sites. The molecular basis of these structures is formed by proteins or protein complexes termed tethers, which attach partner organelles to the surface of LDs. Here, we describe the structural and functional characteristics of recently identified LD tethers. Intriguingly, these LD tethers have additional features, such as the structural capacity to form tri-organellar contacts, domains specialized for interorganellar bulk lipid transfer, and connections to specific lipid metabolism enzymes, which might collectively contribute to the key role of LDs in cellular lipid flux.
{"title":"Tethering Fat: Tethers in Lipid Droplet Contact Sites","authors":"Maria Bohnert","doi":"10.1177/2515256420908142","DOIUrl":"https://doi.org/10.1177/2515256420908142","url":null,"abstract":"Lipid droplets (LDs) are central hubs in cellular lipid handling. They serve as lipid storage organelles and are involved in neutral lipid biosynthesis and breakdown as well as in the production of phospholipids and sterols. For communication with other organelles, LDs are heavily engaged in contact sites. The molecular basis of these structures is formed by proteins or protein complexes termed tethers, which attach partner organelles to the surface of LDs. Here, we describe the structural and functional characteristics of recently identified LD tethers. Intriguingly, these LD tethers have additional features, such as the structural capacity to form tri-organellar contacts, domains specialized for interorganellar bulk lipid transfer, and connections to specific lipid metabolism enzymes, which might collectively contribute to the key role of LDs in cellular lipid flux.","PeriodicalId":87951,"journal":{"name":"Contact","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78455472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-03-01DOI: 10.1177/2515256420912090
W. Henne
Lipid droplets (LDs) are the primary lipid-storage compartments of eukaryotes and feature a unique architecture distinct from membrane-bound organelles. Observed for over a century but initially ignored, recent cell biological, structural, and modeling studies provide new insights into how LDs are made, how they form connections with other organelles, and the roles they play in human physiology and disease. In this brief review, we highlight some key insights that helped define the LD and its roles in the cell. We also summarize new studies of molecular tethers that facilitate the LD interorganelle crosstalk and emerging technologies that provide key insights into the functions and organization of LDs.
{"title":"The Molecular Era of Lipid Droplets","authors":"W. Henne","doi":"10.1177/2515256420912090","DOIUrl":"https://doi.org/10.1177/2515256420912090","url":null,"abstract":"Lipid droplets (LDs) are the primary lipid-storage compartments of eukaryotes and feature a unique architecture distinct from membrane-bound organelles. Observed for over a century but initially ignored, recent cell biological, structural, and modeling studies provide new insights into how LDs are made, how they form connections with other organelles, and the roles they play in human physiology and disease. In this brief review, we highlight some key insights that helped define the LD and its roles in the cell. We also summarize new studies of molecular tethers that facilitate the LD interorganelle crosstalk and emerging technologies that provide key insights into the functions and organization of LDs.","PeriodicalId":87951,"journal":{"name":"Contact","volume":"40 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86563591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}