Biophysical parameters of the Sec14 phospholipid exchange cycle – Effect of lipid packing in membranes

Sec14, a yeast phosphatidylinositol/phosphatidylcholine transfer protein, functions at the trans-Golgi membranes. It lacks domains involved in protein-protein or protein-lipid interactions and consists solely of Sec14 domain; hence, mechanism underlying function proper sites remains unclear. In this study, we focused on lipid packing membranes evaluated its association with vitro activity. Phospholipid assays using pyrene-labelled phosphatidylcholine suggested that increased membrane curvature as well incorporation phosphatidylethanolamine accelerated transfer. The quantity membrane-bound significantly these membranes, indicating “packing defects” promote binding phospholipid Sec14. Increased levels unsaturation promoted Sec14-mediated PC transfer, but had little effect protein. Our results demonstrate possibility location are regulated by states produced translocase activity network.