PKD is a kinase of Vps34 that mediates ROS-induced autophagy downstream of DAPk

Cell Death Differ. 2012 May;19(5):788-97. doi: 10.1038/cdd.2011.149. Epub 2011 Nov 18.

Abstract

Autophagy, a process in which cellular components are engulfed and degraded within double-membrane vesicles termed autophagosomes, has an important role in the response to oxidative damage. Here we identify a novel cascade of phosphorylation events, involving a network of protein and lipid kinases, as crucial components of the signaling pathways that regulate the induction of autophagy under oxidative stress. Our findings show that both the tumor-suppressor death-associated protein kinase (DAPk) and protein kinase D (PKD), which we previously showed to be phosphorylated and consequently activated by DAPk, mediate the induction of autophagy in response to oxidative damage. Furthermore, we map the position of PKD within the autophagic network to Vps34, a lipid kinase whose function is indispensable for autophagy, and demonstrate that PKD is found in the same molecular complex with Vps34. PKD phosphorylates Vps34, leading to activation of Vps34, phosphatydilinositol-3-phosphate (PI(3)P) formation, and autophagosome formation. Consistent with its identification as a novel inducer of the autophagic machinery, we show that PKD is recruited to LC3-positive autophagosomes, where it localizes specifically to the autophagosomal membranes. Taken together, our results describe PKD as a novel Vps34 kinase that functions as an effecter of autophagy under oxidative stress.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis Regulatory Proteins / genetics
  • Apoptosis Regulatory Proteins / metabolism*
  • Autophagy / genetics
  • Autophagy / physiology*
  • Calcium-Calmodulin-Dependent Protein Kinases / genetics
  • Calcium-Calmodulin-Dependent Protein Kinases / metabolism*
  • Cell Line
  • Class III Phosphatidylinositol 3-Kinases / genetics
  • Class III Phosphatidylinositol 3-Kinases / metabolism*
  • Death-Associated Protein Kinases
  • Electrophoresis, Polyacrylamide Gel
  • Immunoprecipitation
  • Mass Spectrometry
  • Microscopy, Electron, Transmission
  • Oxidative Stress / genetics
  • Oxidative Stress / physiology
  • Protein Kinase C / genetics
  • Protein Kinase C / metabolism*
  • RNA Interference
  • Reactive Oxygen Species / metabolism

Substances

  • Apoptosis Regulatory Proteins
  • Reactive Oxygen Species
  • Class III Phosphatidylinositol 3-Kinases
  • protein kinase D
  • Death-Associated Protein Kinases
  • Protein Kinase C
  • Calcium-Calmodulin-Dependent Protein Kinases