Profilin binding to sub-micellar concentrations of phosphatidylinositol (4,5) bisphosphate and phosphatidylinositol (3,4,5) trisphosphate.

P. MOENS; LUIS A. BAGATOLLI

BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2007 vol. 1768 p. 439 - 439

0005-2736

rofilin is a small (12-15 kDa) actin binding protein which promotes filament turnover. Profilin is also involved in the signaling pathway linking receptors in the cell membrane to the microfilament system within the cell. Profilin is thought to play critical roles in this signaling pathway through its interaction with phosphatidylinositol 4,5-bisphosphate [PI(4,5)P(2)] and phosphatidylinositol 3,4,5-trisphosphate [PI(3,4,5)P(3)] (P.J. Lu, W.R. Shieh, S.G. Rhee, H.L. Yin, C.S. Chen, Lipid products of phosphoinositide 3-kinase bind human profilin with high affinity, Biochemistry 35 (1996) 14027-14034). To date, profilin´s interaction with polyphosphoinositides (PPI) has only been studied in micelles or small vesicles. Profilin binds with high affinity to small clusters of PI(4,5)P(2) molecules. In this work, we investigated the interactions of profilin with sub-micellar concentrations of PI(4,5)P(2) and PI(3,4,5)P(3). Fluorescence anisotropy was used to determine the relevant dissociati