Lipid droplets at a glance

Guo, Yi; Cordes, Kimberly R.; Farese, Robert V.; Walther, Tobias C.

doi:10.1242/jcs.037630

Cited by 354 publications

(336 citation statements)

References 36 publications

Supporting

Mentioning

320

Contrasting

Unclassified

Order By: Relevance

“…The main model for OB biogenesis relies on the budding of LDs from the ER followed by the fusion of small OBs to form larger ones (Murphy and Vance, 1999;Siloto et al, 2006;Guo et al, 2009), although the mechanisms underlying the delivery of the newly synthesized TAGs to the OB remain unclear. While we did not study these early stages of OB biogenesis, our data clearly showed that OB growth can occur by fusion.…”

Section: Oleosins Ole1 Ole2 and Ole4 Have Different Rolesmentioning

confidence: 99%

Specialization of Oleosins in Oil Body Dynamics during Seed Development in Arabidopsis Seeds

et al. 2014

View full text Add to dashboard Cite

Oil bodies (OBs) are seed-specific lipid storage organelles that allow the accumulation of neutral lipids that sustain plantlet development after the onset of germination. OBs are covered with specific proteins embedded in a single layer of phospholipids. Using fluorescent dyes and confocal microscopy, we monitored the dynamics of OBs in living Arabidopsis (Arabidopsis thaliana) embryos at different stages of development. Analyses were carried out with different genotypes: the wild type and three mutants affected in the accumulation of various oleosins (OLE1, OLE2, and OLE4), three major OB proteins. Image acquisition was followed by a detailed statistical analysis of OB size and distribution during seed development in the four dimensions (x, y, z, and t). Our results indicate that OB size increases sharply during seed maturation, in part by OB fusion, and then decreases until the end of the maturation process. In single, double, and triple mutant backgrounds, the size and spatial distribution of OBs are modified, affecting in turn the total lipid content, which suggests that the oleosins studied have specific functions in the dynamics of lipid accumulation.The seed is a complex, specific structure that allows a quiescent plant embryo to cope with unfavorable germinating conditions and also permits dissemination of the species. To achieve these functions, seeds accumulate reserve compounds that will ensure the survival of the embryo and fuel the growth of the plantlet upon germination. Accumulation of lipids occurs in many eukaryotic cells and is a rather common means of storing carbon and energy. Lipid droplets (LDs) can be found in all eukaryotes, such as yeast (Saccharomyces cerevisiae;

show abstract

Section: Oleosins Ole1 Ole2 and Ole4 Have Different Rolesmentioning

confidence: 99%

Specialization of Oleosins in Oil Body Dynamics during Seed Development in Arabidopsis Seeds

et al. 2014

View full text Add to dashboard Cite

show abstract

“…1,7,8 Understanding LD homeostasis, biogenesis and catabolism is critical for understanding the pathophysiology of lipid storage disorders like obesity, lipodystrophy (abnormal distribution of fat), type2-diabetes, insulin resistance, atherosclerosis and its associated diseases. 9,10 These metabolic diseases have a wide range of crippling symptoms, the treatment options of which are few and not very effective.…”

mentioning

confidence: 99%

Keeping FIT, storing fat: Lipid droplet biogenesis

Choudhary

Golden

Prinz

2016

Worm

View full text Add to dashboard Cite

All eukaryotes store excess lipids in organelles known as lipid droplets (LDs), which play central roles in lipid metabolism. Understanding LD biogenesis and metabolism is critical for understanding the pathophysiology of lipid metabolic disorders like obesity and atherosclerosis. LDs are composed of a core of neutral lipids surrounded by a monolayer of phospholipids that often contains coat proteins. Nascent LDs bud from the endoplasmic reticulum (ER) but the mechanism is not known. In this commentary we discuss our recent finding that a conserved family of proteins called fat storage-inducing transmembrane (FIT) proteins is necessary for LDs budding from the ER. In cells lacking FIT proteins, LDs remain in the ER membrane. C. elegans has a single FIT protein (FITM-2), which we found is essential; almost all homozygous fitm-2 animals die as larvae and those that survive to adulthood give rise to embryos that die as L1 and L2 larvae. Homozygous fitm-2 animals have a number of abnormalities including a significant decrease in intestinal LDs and dramatic defects in muscle development. Understanding how FIT proteins mediate LD biogenesis and what roles they play in lipid metabolism and development are fascinating challenges for the future. Lipid droplets (LDs) are the major storage organelle for fat in most organisms. 1,2 LDs play a key role in lipid homeostasis. However, recent findings suggest that LDs have many other functions; they play roles in protein degradation 3,4 and the endoplasmic reticulum (ER) stress response, 5 they act as sites for assembly of infectious virions, 6 are involved in membrane trafficking and signal transduction, and act as a temporary storehouse of proteins. 1,7,8 Understanding LD homeostasis, biogenesis and catabolism is critical for understanding the pathophysiology of lipid storage disorders like obesity, lipodystrophy (abnormal distribution of fat), type2-diabetes, insulin resistance, atherosclerosis and its associated diseases. 9,10 These metabolic diseases have a wide range of crippling symptoms, the treatment options of which are few and not very effective.We are still just beginning to understand the biogenesis of LDs. Before discussing what is known about this process, it is important to understand how LDs differ from other organelles. Most organelles are surrounded by a membrane bilayer that separates the lumen of the organelle from the cytoplasm. In contrast LDs have a phospholipid monolayer that surrounds a core of neutral lipids. [11][12][13][14] LDs are surrounded by coat proteins; perilipins (PLIN) in mammals, and oleosins in plants, that regulate the access of lipid lipases to the neutral lipid core (for review see [15][16][17][18] ). However, yeast and C. elegans lack LD coat proteins, 19,20 suggesting that coat proteins are not necessary for LD formation or maintenance. Indeed, emulsions of neutral lipids and phospholipids without proteins form artificial LDs in vitro.How do LDs form in cells? A number of models have been proposed but the simplest is one that ...

show abstract

“…LD growth is generally considered to occur by two mechanisms [7]. One is growth of LD itself and the other is fusion of the LDs.…”

Section: Discussionmentioning

confidence: 99%

Negatively‐charged residues in the polar carboxy‐terminal region in FSP27 are indispensable for expanding lipid droplets

et al. 2016

View full text Add to dashboard Cite

FSP27 has an important role in large lipid droplet (LD) formation because it exchanges lipids at the contact site between LDs. In the present study, we clarify that the amino-terminal domain of FSP27 (amino acids 1-130) is dispensable for LD enlargement, although it accelerates LD growth. LD expansion depends on the carboxy-terminal domain of FSP27 (amino acids 131-239). Especially, the negative charge of the acidic residues (D215, E218, E219 and E220) in the polar carboxy-terminal region (amino acids 202-239) is essential for the enlargement of LD. We propose that the carboxy-terminal domain of FSP27 has a crucial role in LD expansion, whereas the aminoterminal domain only has a supportive role.Keywords: adipocyte; fat specific protein of 27 kDa; lipid droplet; lipid droplet enlargement; negatively-charged amino acid; structure and function Obesity increases dramatically [1]. It develops as a consequence of nutritional excess and insufficient exercise and is characterized by excessive triacylglycerol (TAG) storage in the form of lipid droplets (LD) in adipose tissue. This results in adipose tissue inflammation and the deregulation of adipokines, both of which induce systemic insulin resistance [2,3]. At the same time, a hallmark of obesity is TAG accumulation in the liver and skeletal muscle, which is also important for inducing insulin resistance in these tissues [4]. These findings highlight the significance of lipid accumulation in insulin-sensitive organs in the development of insulin resistance and type 2 diabetes.LDs comprise a central core of neutral lipids containing TAG and cholesterol ester that is surrounded by a phospholipid monolayer [5,6]. This monolayer of LD is decorated with a variety of proteins that contribute to the formation of the droplet, the synthesis and hydrolysis of its lipids, and the movement of these lipids to specific intracellular and secretory pathways [6,7]. The ability to store TAG in LDs is evolutionarily conserved in yeast, plants, invertebrates and vertebrates [8]. In mammals, excess energy is primarily stored as TAG in LDs of adipose tissue. In particular, white adipocytes comprise specifically differentiated cells for storing TAG as a large unilocular LD that occupies a majority of the cell volume. The LD size can be in the 100 lm range [9]. TAG storage in LDs serves a vital role as a major store of energy supply. In the case of energy demand, such as starvation and exercise, TAG reserves are hydrolyzed by lipolysis to supply free fatty acid to various tissues. LDs are also detected in non-adipose cells; however, non-adipocyte LDs are usually much smaller than adipocyte LDs.Abbreviations CIDE, cell death-inducing DFFA-like effector; FSP27, fat specific protein of 27 kDa; LD, lipid droplet; TAG, triacylglycerol. 750FEBS Letters 590 (2016) 750-759 ª

show abstract

Lipid droplets at a glance

Cited by 354 publications

References 36 publications

Specialization of Oleosins in Oil Body Dynamics during Seed Development in Arabidopsis Seeds

Specialization of Oleosins in Oil Body Dynamics during Seed Development in Arabidopsis Seeds

Keeping FIT, storing fat: Lipid droplet biogenesis

Negatively‐charged residues in the polar carboxy‐terminal region in FSP27 are indispensable for expanding lipid droplets

Contact Info

Product

Resources

About