ABCA1 Mediates Unfolding of Apolipoprotein AI N Terminus on the Cell Surface Before Lipidation and Release of Nascent High-Density Lipoprotein

Abstract

We identified a third activity of ABCA1, the ability to unfold the N terminus of apoAI on the cell surface. Our results support a model in which unfolded apoAI on the cell surface is an intermediate in its lipidation and that, once apoAI is lipidated, it forms an unstable structure that is rapidly released from the cells to generate high-density lipoprotein.