Journal Article

Identification of ROCK1 kinase as a critical regulator of Beclin1-mediated autophagy during metabolic stress

Raj, Lakshmi, Bouley, Richard, Kim, Young-Bum, Lee, Seung-Hwan, Chu, Kiki, Gurkar, Aditi U., Dunn, Sandra E., Lee, Sam W., Mandinova, Anna

2013

Overview

The Ser/Thr Rho kinase 1 (ROCK1) is known to have major roles in a wide range of cellular activities, including those involved in tumour metastasis and apoptosis. Here we identify an indispensable function of ROCK1 in metabolic stress-induced autophagy. Applying a proteomics approach, we characterize Beclin1, a proximal component of the phosphoinositide 3-kinase class III lipid–kinase complex that induces autophagy, as an interacting partner of ROCK1. Upon nutrient deprivation, activated ROCK1 promotes autophagy by binding and phosphorylating Beclin1 at Thr119. This results in the specific dissociation of the Beclin1–Bcl-2 complex without affecting the Beclin1–UVRAG interaction. Conversely, inhibition of ROCK1 activity increases Beclin1–Bcl-2 association, thus reducing nutritional stress-mediated autophagy. Genetic knockout of ROCK1 function in mice also leads to impaired autophagy as evidenced by reduced autophagosome formation. These results show that ROCK1 acts as a prominent upstream regulator of Beclin1-mediated autophagy and maintains a homeostatic balance between apoptosis and autophagy. The kinase ROCK1 has been implicated in apoptosis and other cellular functions. Here Gurkar et al . show that ROCK1 phosphorylates the autophagy regulator Beclin1, which activates autophagy by disrupting the association between Beclin-1 and Bcl-2.

• Publisher: Nature Publishing Group UK,Nature Publishing Group
• Subject: 631/80/82/39 / 631/80/86/2366 / Animals / Apoptosis / Apoptosis - genetics / Apoptosis Regulatory Proteins - genetics / Apoptosis Regulatory Proteins - metabolism / Autophagy / Autophagy - genetics / Beclin-1 / Cancer / Cell Communication / Cell death / Cell Line, Tumor / Gene Expression Regulation / Glucose / Humanities and Social Sciences / Humans / Kinases / Membrane Proteins - genetics / Membrane Proteins - metabolism / Metabolism / Mice / Mice, Transgenic / multidisciplinary / Phagosomes - metabolism / Phosphatase / Phosphorylation / Protein Binding / Proteins / Proto-Oncogene Proteins c-bcl-2 - genetics / Proto-Oncogene Proteins c-bcl-2 - metabolism / rho-Associated Kinases - antagonists & inhibitors / rho-Associated Kinases - genetics / rho-Associated Kinases - metabolism / RNA, Small Interfering - genetics / RNA, Small Interfering - metabolism / Science / Science (multidisciplinary) / Signal Transduction / Stress, Physiological / Tumor Suppressor Proteins - genetics / Tumor Suppressor Proteins - metabolism