Researchers have found one the basic components of fat metabolism, which is important news, as diseases related to obesity are on rise.
Up till now, it was a mystery how the metabolism of fat takes place from increased level of the hormones like adrenaline as a result of fight or flight response and/or physical activity.
Fats are present in the particular compartments within the fat cell. These compartments are referred to as “Lipid Droplets” (LD). It was an idea that the proteins involved in the metabolism of fats must present in close proximity on the surface of the lipid droplets and have to act together. This bunching of proteins takes place with the help of, what is called as, anchoring proteins.
Researchers from Taskén group have demonstrated the important role of the anchoring protein OPA1 in lipid metabolism. This research published in the EMBO journal.
Dr. Greenberg and colleagues from Harvard and Stanford University underlined the importance of these findings in a research highlight,
The observation of [OPA1] on the LD surface provides an important step in understanding the regulation of LD biology.
Researchers have reported,
Adrenergic stimulation of adipocytes yields a cAMP signal that activates protein kinase A (PKA). PKA phosphorylates perilipin, a protein localized on the surface of lipid droplets that serves as a gatekeeper to regulate access of lipases converting stored triglycerides to free fatty acids and glycerol in a phosphorylation-dependent manner. Here, we report a new function for optic atrophy 1 (OPA1), a protein known to regulate mitochondrial dynamics, as a dual-specificity A-kinase anchoring protein associated with lipid droplets. By a variety of protein interaction assays, immunoprecipitation and immunolocalization experiments, we show that OPA1 organizes a supramolecular complex containing both PKA and perilipin.
Andrew S Greenberg, Fredric B Kraemer, Krishnakant G Soni, Mark P Jedrychowski, Qing-Wu Yan, Christine E Graham, Thomas A Bowman, Ayla Mansur. Lipid droplet meets a mitochondrial protein to regulate adipocyte lipolysis. The EMBO Journal, 2011; 30 (21): 4337 DOI: 10.1038/emboj.2011.371
Guillaume Pidoux, Oliwia Witczak, Elisabeth Jarnæss, Linda Myrvold, Henning Urlaub, Anne Jorunn Stokka, Thomas Küntziger, Kjetil Taskén. Optic atrophy 1 is an A-kinase anchoring protein on lipid droplets that mediates adrenergic control of lipolysis. The EMBO Journal, 2011; 30 (21): 4371 DOI: 10.1038/emboj.2011.365