The Protein Kinase Akt Acts as a Coat Adaptor in Endocytic Recycling

Abstract

Coat proteins play a central role in vesicular transport by binding to cargoes for their sorting into intracellular pathways. Cargo recognition is mediated by components of the coat complex known as adaptor proteins. We previously showed that ACAP1 (ArfGAP with Coil-coil Ankyrin repeat Protein 1) functions as an adaptor for a clathrin coat complex acting in endocytic recycling. Here, we find that the protein kinase Akt acts as a co-adaptor in this complex, needed in conjunction with ACAP1 to bind cargo proteins for their recycling. Besides advancing the understanding of endocytic recycling, our findings uncover a fundamentally different way that a kinase acts, being an effector rather than a regulator in a cellular event.