| First Author | Cardozo Gizzi AM | Year | 2015 |
| Journal | J Biol Chem | Volume | 290 |
| Issue | 49 | Pages | 29578-92 |
| PubMed ID | 26475860 | Mgi Jnum | J:281194 |
| Mgi Id | MGI:6377845 | Doi | 10.1074/jbc.M115.678821 |
| Citation | Cardozo Gizzi AM, et al. (2015) The Catalytic Efficiency of Lipin 1beta Increases by Physically Interacting with the Proto-oncoprotein c-Fos. J Biol Chem 290(49):29578-92 |
| abstractText | Phosphatidic acid (PA) is a central precursor for membrane phospholipid biosynthesis. The lipin family is a magnesium-dependent type I PA phosphatase involved in de novo synthesis of neutral lipids and phospholipids. The regulation of lipin activity may govern the pathways by which these lipids are synthesized and control the cellular levels of important signaling lipids. Moreover, the proto-oncoprotein c-Fos has an emerging role in glycerolipid synthesis regulation; by interacting with key synthesizing enzymes it is able to increase overall phospho- and glycolipid synthesis. We studied the lipin 1beta enzyme activity in a cell-free system using PA/Triton X-100 mixed micelles as substrate, analyzing it in the presence/absence of c-Fos. We found that lipin 1beta kcat value increases around 40% in the presence of c-Fos, with no change in the lipin 1beta affinity for the PA/Triton X-100 mixed micelles. We also probed a physical interaction between both proteins. Although the c-Fos domain involved in lipin activation is its basic domain, the interaction domain is mapped to the N-terminal c-Fos. In conclusion, we provide evidence for a novel positive regulator of lipin 1beta PA phosphatase activity that is not achieved via altering its subcellular localization or affinity for membranes but rather through directly increasing its catalytic efficiency. |
