The brown adipocyte protein CIDEA promotes lipid droplet fusion via a phosphatidic acid-binding amphipathic helix
- Imperial College London, United Kingdom
- University of Warwick, United Kingdom
- Cornell University, United States
- University of Pittsburgh, United States
- Imperial College London, United States
- Rutgers University, United States
- Babraham Institute, United Kingdom
Abstract
Maintenance of energy homeostasis depends on the highly regulated storage and release of triacylglycerol primarily in adipose tissue and excessive storage is a feature of common metabolic disorders. CIDEA is a lipid droplet (LD)-protein enriched in brown adipocytes promoting the enlargement of LDs which are dynamic, ubiquitous organelles specialized for storing neutral lipids. We demonstrate an essential role in this process for an amphipathic helix in CIDEA, which facilitates embedding in the LD phospholipid monolayer and binds phosphatidic acid (PA). LD pairs are docked by CIDEA trans-complexes through contributions of the N-terminal domain and a C-terminal dimerization region. These complexes, enriched at the LD-LD contact site, interact with the cone-shaped phospholipid PA and likely increase phospholipid barrier permeability, promoting LD fusion by transference of lipids. This physiological process is essential in adipocyte differentiation as well as serving to facilitate the tight coupling of lipolysis and lipogenesis in activated brown fat.
Article and author information
Author details
Reviewing Editor
- Stephen G Young, University of California, Los Angeles, United States
Publication history
- Received: March 13, 2015
- Accepted: November 25, 2015
- Accepted Manuscript published: November 26, 2015 (version 1)
- Accepted Manuscript updated: December 10, 2015 (version 2)
- Version of Record published: February 3, 2016 (version 3)
Copyright
© 2015, Barneda et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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The brown adipocyte protein CIDEA promotes lipid droplet fusion via a phosphatidic acid-binding amphipathic helix
eLife 4:e07485.
https://doi.org/10.7554/eLife.07485
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