| First Author | Miyoshi H | Year | 2007 |
| Journal | J Biol Chem | Volume | 282 |
| Issue | 2 | Pages | 996-1002 |
| PubMed ID | 17114792 | Mgi Jnum | J:118169 |
| Mgi Id | MGI:3698700 | Doi | 10.1074/jbc.M605770200 |
| Citation | Miyoshi H, et al. (2007) Control of adipose triglyceride lipase action by serine 517 of perilipin A globally regulates protein kinase A-stimulated lipolysis in adipocytes. J Biol Chem 282(2):996-1002 |
| abstractText | Phosphorylation of the lipid droplet-associated protein perilipin A (Peri A) mediates the actions of cyclic AMP-dependent protein kinase A (PKA) to stimulate triglyceride hydrolysis (lipolysis) in adipocytes. Studies addressing how Peri A PKA sites regulate adipocyte lipolysis have relied on non-adipocyte cell models, which express neither adipose triglyceride lipase (ATGL), the rate-limiting enzyme for triglyceride catabolism in mice, nor the 'downstream' lipase, hormone-sensitive lipase (HSL). ATGL and HSL are robustly expressed by adipocytes that we generated from murine embryonic fibroblasts of perilipin knock-out mice. Adenoviral expression of Peri A PKA site mutants in these cells reveals that mutation of serine 517 alone is sufficient to abrogate 95% of PKA (forskolin)-stimulated fatty acid (FA) and glycerol release. Moreover, a 'phosphomimetic' (aspartic acid) substitution at serine 517 enhances PKA-stimulated FA release over levels obtained with wild type Peri A. Studies with ATGL-and HSL-directed small hairpin RNAs demonstrate that 1) ATGL activity is required for all PKA-stimulated FA and glycerol release in murine embryonic fibroblast adipocytes and 2) all PKA-stimulated FA release in the absence of HSL activity requires serine 517 phosphorylation. These results provide the first demonstration that Peri A regulates ATGL-dependent lipolysis and identify serine 517 as the Peri A PKA site essential for this regulation. The contributions of other PKA sites to PKA-stimulated lipolysis are manifested only in the presence of phosphorylated or phosphomimetic serine 517. Thus, serine 517 is a novel 'master regulator' of PKA-stimulated adipocyte lipolysis. |
