Lipotransin: a novel docking protein for hormone-sensitive lipase.

Lipotransin is a novel hormone-sensitive lipase (HSL)-interacting protein that appears to translocate HSL to the lipid droplet. The interaction of the two proteins depends upon the phosphorylation of HSL by protein kinase A. Once formed, the complex is dissociated by ATP hydrolysis, due to the ATPase activity of lipotransin. In 3T3L1 adipocytes, insulin produces a stable complex between the proteins, due to a modification of lipotransin. Thus, lipotransin is a novel docking protein that may direct the hormonally regulated redistribution of hormone-sensitive lipase.