Lipid droplets: FSP27 knockout enhances their sizzle
Vishwajeet Puri, Michael P. Czech
Vishwajeet Puri, Michael P. Czech
Published July 24, 2008
Citation Information: J Clin Invest. 2008;118(8):2693-2696. https://doi.org/10.1172/JCI36554.
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Commentary

Lipid droplets: FSP27 knockout enhances their sizzle

Abstract

Fat-specific protein of 27 kDa (FSP27) is a highly expressed adipocyte protein that promotes triglyceride accumulation within lipid droplets. In this issue of the JCI, Nishino et al. show that FSP27 also helps to maintain the characteristically large unilocular lipid droplet structure within each white adipocyte (see the related article beginning on page 2808). Fragmentation of lipid droplets in white adipocytes from FSP27-KO mice caused both increased lipolysis and upregulation of genes enhancing mitochondrial oxidative metabolism. This increased energy expenditure in turn protected the mice from diet-induced obesity and insulin resistance. These new results highlight powerful mechanisms that tightly coordinate rates of triglyceride storage in lipid droplets with mitochondrial fatty acid oxidation in white adipocytes.

Authors

Vishwajeet Puri, Michael P. Czech

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Figure 1

FSP27 is required for the unilocular structure of lipid droplets in white adipocytes.

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FSP27 is required for the unilocular structure of lipid droplets in whit...
According to this model, the biogenesis of small lipid droplets in the endoplasmic reticulum is followed by their subsequent fusion in the cytoplasm of white adipocytes. Proteins thought to be involved in cell membrane fusion processes (e.g., N-ethylmaleimide–sensitive factor [NSF], soluble NSF attachment protein [α-SNAP], and SNAP receptors [SNAREs]) might activate these fusion processes. Lipid droplet proteins (dark blue) such as perilipin, tail-interacting protein of 47 kDa, S3-12, adipose differentiation–related protein, and others may be involved in packaging the lipids in multilocular lipid droplets in adipocytes. According to Nishino et al. (1), in their current study in this issue of the JCI, FSP27 plays a key role in the formation of unilocular lipid droplets in adipocytes of WAT, since lipid droplets are shown to be multilocular in FSP27-KO mice.