Fretting about fat: a new look at the lipid droplet surface and the roundabout role of Plin2 in cellular lipid storage. Focus on “Direct interaction of Plin2 with lipids on the surface of lipid droplets: a live cell FRET analysis”

2012 ◽  
Vol 303 (7) ◽  
pp. C713-C714 ◽  
Author(s):  
Jeffrey S. Elmendorf
Keyword(s):  
Lipid Droplet ◽  
Lipid Droplets ◽  
Direct Interaction ◽  
Droplet Surface ◽  
Lipid Storage ◽  
Live Cell ◽  
Cellular Lipid ◽  
New Look

scholarly journals Recruitment of Peroxin14 to lipid droplets affects triglyceride storage in Drosophila

2021 ◽  
Author(s):  
Matthew Anderson-Baron ◽  
Kazuki Ueda ◽  
Julie Haskins ◽  
Sarah C Hughes ◽  
Andrew Simmonds
Keyword(s):  
Neutral Lipid ◽  
Lipid Droplet ◽  
Functional Role ◽  
Lipid Droplets ◽  
Droplet Surface ◽  
Lipid Homeostasis ◽  
Cellular Lipid ◽  
Peroxisome Biogenesis ◽  
Drosophila Cells

The activity of multiple organelles must be coordinated to ensure cellular lipid homeostasis. This includes the peroxisomes which metabolise certain lipids and lipid droplets which act as neutral lipid storage centres. Direct organellar contact between peroxisomes and lipid droplets has been observed, and interaction between proteins associated with the membranes of these organelles has been shown, but the functional role of these interactions is not clear. In Drosophila cells, we identified a novel localization of a subset of three transmembrane Peroxin proteins (Peroxin3, Peroxin13, and Peroxin14), normally required for peroxisome biogenesis, to newly formed lipid droplets. This event was not linked to significant changes in peroxisome size or number, nor was recruitment of other Peroxin proteins or mature peroxisomes observed. The presence of these Peroxin proteins at lipid droplets influences their function as changes in the relative levels of Peroxin14 associated with the lipid droplet surface directly affected the presence of regulatory perilipin and lipases with corresponding effects on triglyceride storage.

scholarly journals The Lipid Droplet Knowledge Portal: A resource for systematic analyses of lipid droplet biology

2021 ◽  
Author(s):  
Niklas Mejhert ◽  
Katlyn R Gabriel ◽  
Natalie Krahmer ◽  
Leena Kuruvilla ◽  
Chandramohan Chitraju ◽  
...  
Keyword(s):  
Lipid Droplet ◽  
Lipid Droplets ◽  
Human Genetics ◽  
Cell Types ◽  
Lipid Storage ◽  
Cellular Lipid ◽  
High Confidence ◽  
Genome Wide ◽  
Knowledge Portal

Lipid droplets (LDs) are organelles of cellular lipid storage with fundamental roles in energy metabolism and cell membrane homeostasis. There has been an explosion of research into the biology of LDs, in part due to their relevance in diseases of lipid storage, such as atherosclerosis, obesity, type 2 diabetes mellitus, and hepatic steatosis. Consequently, there is an increasing need for a resource that combines large datasets from systematic analyses of LD biology. Here we integrate high-confidence, systematically generated data on studies of LDs in the framework of an online platform named the Lipid Droplet Knowledge Portal. This scalable and interactive portal includes comprehensive datasets, across a variety of cell types, for LD biology, including transcriptional profiles of induced lipid storage, organellar proteomics, genome-wide screen phenotypes, and ties to human genetics. This new resource is a powerful platform that can be utilized to uncover new determinants of lipid storage.

scholarly journals Direct interaction of Plin2 with lipids on the surface of lipid droplets: a live cell FRET analysis

2012 ◽  
Vol 303 (7) ◽  
pp. C728-C742 ◽  
Author(s):  
Avery L. McIntosh ◽  
Subramanian Senthivinayagam ◽  
Kenneth C. Moon ◽  
Shipra Gupta ◽  
Joel S. Lwande ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Cholesteryl Ester ◽  
Lipid Droplet ◽  
Lipid Droplets ◽  
Nile Red ◽  
Direct Interaction ◽  
Structure And Function ◽  
Live Cell ◽  
High Yield ◽  
And Function

Despite increasing awareness of the health risks associated with excess lipid storage in cells and tissues, knowledge of events governing lipid exchange at the surface of lipid droplets remains unclear. To address this issue, fluorescence resonance energy transfer (FRET) was performed to examine live cell interactions of Plin2 with lipids involved in maintaining lipid droplet structure and function. FRET efficiencies ( E) between CFP-labeled Plin2 and fluorescently labeled phosphatidylcholine, sphingomyelin, stearic acid, and cholesterol were quantitated on a pixel-by-pixel basis to generate FRET image maps that specified areas with high E (>60%) in lipid droplets. The mean E and the distance R between the probes indicated a high yield of energy transfer and demonstrated molecular distances on the order of 44–57 Å, in keeping with direct molecular contact. In contrast, FRET between CFP-Plin2 and Nile red was not detected, indicating that the CFP-Plin2/Nile red interaction was beyond FRET proximity (>100 Å). An examination of the effect of Plin2 on cellular metabolism revealed that triacylglycerol, fatty acid, and cholesteryl ester content increased while diacylglycerol remained constant in CFP-Plin2-overexpressing cells. Total phospholipids also increased, reflecting increased phosphatidylcholine and sphingomyelin. Consistent with these results, expression levels of enzymes involved in triacylglycerol, cholesteryl ester, and phospholipid synthesis were significantly upregulated in CFP-Plin2-expressing cells while those associated with lipolysis either decreased or were unaffected. Taken together, these data show for the first time that Plin2 interacts directly with lipids on the surface of lipid droplets and influences levels of key enzymes and lipids involved in maintaining lipid droplet structure and function.

scholarly journals Lipids Affect the Cryptococcus neoformans-Macrophage Interaction and Promote Nonlytic Exocytosis

2017 ◽  
Vol 85 (12) ◽  
Author(s):  
Sabrina J. Nolan ◽  
Man Shun Fu ◽  
Isabelle Coppens ◽  
Arturo Casadevall
Keyword(s):  
Oleic Acid ◽  
Cryptococcus Neoformans ◽  
Lipid Droplets ◽  
Fungal Pathogens ◽  
Cellular Lipid ◽  
Content Type ◽  
Acid Supplementation

ABSTRACT Many microbes exploit host cellular lipid droplets during the host-microbe interaction, but this phenomenon has not been extensively studied for fungal pathogens. In this study, we analyzed the role of lipid droplets during the interaction of Cryptococcus neoformans with macrophages in the presence and the absence of exogenous lipids, in particular, oleate. The addition of oleic acid increased the frequency of lipid droplets in both C. neoformans and macrophages. C. neoformans responded to oleic acid supplementation by faster growth inside and outside macrophages. Fungal cells were able to harvest lipids from macrophage lipid droplets. Supplementation of C. neoformans and macrophages with oleic acid significantly increased the rate of nonlytic exocytosis while having no effect on lytic exocytosis. The process for lipid modulation of nonlytic exocytosis was associated with actin changes in macrophages. In summary, C. neoformans harvests lipids from macrophages, and the C. neoformans-macrophage interaction is modulated by exogenous lipids, providing a new tool for studying nonlytic exocytosis.

773 HEPATITIS C VIRUS AND LIPID DROPLETS: ROLE OF SEIPIN IN LIPID DROPLET MATURATION AND VIRAL LIFE CYCLE

2011 ◽  
Vol 54 ◽  
pp. S311 ◽  
Author(s):  
S. Clement ◽  
C. Fauvelle ◽  
S. Pascarella ◽  
S. Conzelmann ◽  
V. Kaddai ◽  
...  
Keyword(s):  
Life Cycle ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Lipid Droplet ◽  
Lipid Droplets ◽  
Viral Life Cycle

scholarly journals Seipin-Mediated Contacts as Gatekeepers of Lipid Flux at the Endoplasmic Reticulum–Lipid Droplet Nexus 

Contact ◽  
2020 ◽  
Vol 3 ◽  
pp. 251525642094582
Author(s):  
Veijo T. Salo ◽  
Maarit Hölttä-Vuori ◽  
Elina Ikonen
Keyword(s):  
Endoplasmic Reticulum ◽  
Lipid Metabolism ◽  
Recent Work ◽  
Lipid Droplet ◽  
Lipid Droplets ◽  
Intimate Relationship

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.

Subcellular localization of skeletal muscle lipid droplets and PLIN family proteins OXPAT and ADRP at rest and following contraction in rat soleus muscle

2012 ◽  
Vol 302 (1) ◽  
pp. R29-R36 ◽  
Author(s):  
Rebecca E. K. MacPherson ◽  
Eric A. F. Herbst ◽  
Erica J. Reynolds ◽  
Rene Vandenboom ◽  
Brian D. Roy ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Lipid Droplet ◽  
Protein Interactions ◽  
Lipid Droplets ◽  
Droplet Surface ◽  
Protein Protein Interactions ◽  
Muscle Lipid ◽  
Droplet Distribution ◽  
Associated Proteins ◽  
Skeletal Muscle Lipid

Skeletal muscle lipid droplet-associated proteins (PLINs) are thought to regulate lipolysis through protein-protein interactions on the lipid droplet surface. In adipocytes, PLIN2 [adipocyte differentiation-related protein (ADRP)] is found only on lipid droplets, while PLIN5 (OXPAT, expressed only in oxidative tissues) is found both on and off the lipid droplet and may be recruited to lipid droplet membranes when needed. Our purpose was to determine whether PLIN5 is recruited to lipid droplets with contraction and to investigate the myocellular location and colocalization of lipid droplets, PLIN2, and PLIN5. Rat solei were isolated, and following a 30-min equilibration period, they were assigned to one of two groups: 1) 30 min of resting incubation and 2) 30 min of stimulation ( n = 10 each). Immunofluorescence microscopy was used to determine subcellular content, distribution, and colocalization of lipid droplets, PLIN2, and PLIN5. There was a main effect for lower lipid and PLIN2 content in stimulated compared with rested muscles ( P < 0.05). Lipid droplet distribution declined exponentially from the sarcolemma to the fiber center in the rested muscles ( P = 0.001, r2= 0.99) and linearly in stimulated muscles (slope = −0.0023 ± 0.0006, P < 0.001, r2= 0.93). PLIN2 distribution declined exponentially from the sarcolemma to the fiber center in both rested and stimulated muscles ( P < 0.0001, r2= 0.99 rest; P = 0.0004, r2= 0.98 stimulated), while PLIN5 distribution declined linearly (slope = −0.0085 ± 0.0009, P < 0.0001, r2= 0.94 rest; slope=−0.0078 ± 0.0010, P = 0.0003, r2= 0.91 stimulated). PLIN5-lipid droplets colocalized at rest with no difference poststimulation ( P = 0.47; rest r2= 0.55 ± 0.02, stimulated r2= 0.58 ± 0.03). PLIN2-lipid droplets colocalized at rest with no difference poststimulation ( P = 0.48; rest r2= 0.66 ± 0.02, stimulated r2= 0.65 ± 0.02). Contrary to our hypothesis, these results show that PLIN5 is not recruited to lipid droplets with contraction in isolated skeletal muscle.

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