Arachidonic acid does not grease the exocytotic SNARE machinery

Abstract

It has been proposed that arachidonic acid stimulates neurite outgrowth by specifically activating syntaxin 3, a SNARE proteins that mediates the fusion of transport vesicles with the plasma membrane and is thus instrumental for the insertion of new membrane needed for cell growth and proliferation. Considering the important role of arachidonic acid and other polyunsaturated fatty acids for human health, these findings would have wide implications for everyday life. Here, I have report that the effect of arachidonic acid is caused by a nonspecific, detergent-like action on SNARE proteins in vitro. The action requires unphysiologically high concentrations, is mimicked by several detergents or detergent-like substances forming micelles regardless of whether arachidonic acid is present or not, and is thus highly unlikely to be of any physiological significance for SNARE function.