The catalytic efficiency of lipin 1β increases by physically interacting with the proto-oncoprotein c-Fos

CARDOZO GIZZI, ANDRES M.; PRUCCA, CESAR G.; GAVEGLIO, VIRGINIA L.; RENNER, MARIANNE L.; PASQUARÉ, SUSANA J.; CAPUTTO, BEATRIZ L.

JOURNAL OF BIOLOGICAL CHEMISTRY

AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC

Año: 2015 vol. 290 p. 29578 - 29578

0021-9258

hosphatidic 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 1β 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 1β kcat value increases around 40% in the presence of c-Fos, with no change in the lipin 1β affinity for the PA/Triton X-100 mixed micelles. We also probed a physical interaction between both proteins. Although the c-Fos do