Ubiquitin carboxyl-terminal hydrolase 11 promotes autophagy by de-ubiquitinating and stabilizing Beclin-1

Abstract

Autophagy is a major degradation process that degrades and recycles cytoplasmic materials through lysosome for maintaining cellular homeostasis. Dysregulated autophagy is linked with numerous human diseases including cancer. Autophagy marker protein B-cell lymphoma-2 interacting protein 1 (Beclin-1) is essential for autophagosome initiation and maturation. Recently, Ubiquitin carboxyl-terminal hydrolase 11 (USP11) has been reported to promote or inhibit autophagy without identification of any direct target. Here through biochemical reaction in vitro, we demonstrate that USP11 directly interacts with Beclin-1. Both in vitro and in vivo de-ubiquitination assays revealed that USP11 de-ubiquitinates Beclin-1. USP11-mediated de-ubiquitination stabilized Beclin-1 and enhanced the formation of the autophagy-specific class III phosphatidylinositol 3-kinase complexes 1 and 2, thereby promoting autophagy. Together, our results demonstrated that USP11 promotes autophagy under unperturbed conditions by de-ubiquitinating and stabilizing Beclin-1 which may serve as a therapeutic target for autophagy-related diseases.