The Catalytic Efficiency of Lipin 1β Increases by Physically Interacting with the Proto-oncoprotein c-Fos.

CARDOZO GIZZI AM; PRUCCA CG; GAVEGLIO VL; RENNER ML; PASQUARE SJ; CAPUTTO BL

AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC

Lugar: Bethesda, Maryland; Año: 2015 vol. 290 p. 29578 - 29578

hosphatidic acid (PA) is a central precursor for membranephospholipid biosynthesis. The lipin family is a magnesium-dependenttype I PA phosphatase involved in de novo synthesis ofneutral lipids and phospholipids. The regulation of lipin activitymay govern the pathways by which these lipids are synthesizedand control the cellular levels of important signaling lipids.Moreover, the proto-oncoprotein c-Fos has an emerging role inglycerolipid synthesis regulation; by interacting with key synthesizingenzymes it is able to increase overall phospho- andglycolipid synthesis. We studied the lipin 1 enzyme activity ina cell-free system using PA/Triton X-100 mixed micelles as substrate,analyzing it in the presence/absence of c-Fos. We foundthat lipin 1 kcat value increases around 40% in the presence ofc-Fos, with no change in the lipin 1 affinity for the PA/TritonX-100 mixed micelles. We also probed a physical interactionbetween both proteins. Although the c-Fos domain involved inlipin activation