Cellular energy stress induces AMPK-mediated regulation of glioblastoma cell proliferation by PIKE-A phosphorylation

Cell Death Dis. 2019 Mar 4;10(3):222. doi: 10.1038/s41419-019-1452-1.

Abstract

Phosphoinositide 3-kinase enhancer-activating Akt (PIKE-A), which associates with and potentiates Akt activity, is a pro-oncogenic factor that play vital role in cancer cell survival and growth. However, PIKE-A physiological functions under energy/nutrient deficiency are poorly understood. The AMP-activated protein kinase (AMPK) is an evolutionarily conserved serine/threonine kinase that is a principal regulator of energy homeostasis and has a critical role in metabolic disorders and cancers. In this present study, we show that cellular energy stress induces PIKE-A phosphorylation mediated by AMPK activation, thereby preventing its carcinogenic action. Moreover, AMPK directly phosphorylates PIKE-A Ser-351 and Ser-377, which become accessible for the interaction with 14-3-3β, and in turn stimulates nuclear translocation of PIKE-A. Nuclear PIKE-A associates with CDK4 and then disrupts CDK4-cyclinD1 complex and inhibits the Rb pathway, resulting in cancer cell cycle arrest. Our data uncover a molecular mechanism and functional significance of PIKE-A phosphorylation response to cellular energy status mediated by AMPK.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • 14-3-3 Proteins / metabolism
  • AMP-Activated Protein Kinases / metabolism
  • AMP-Activated Protein Kinases / physiology*
  • Cell Nucleus / metabolism
  • Cell Proliferation*
  • Cyclin-Dependent Kinase 4 / metabolism
  • Energy Metabolism
  • Enzyme Activation
  • Feedback, Physiological
  • GTP-Binding Proteins / metabolism*
  • GTPase-Activating Proteins / metabolism*
  • Glioblastoma / pathology*
  • Phosphorylation
  • Signal Transduction
  • Stress, Physiological

Substances

  • 14-3-3 Proteins
  • GTPase-Activating Proteins
  • Cyclin-Dependent Kinase 4
  • AMP-Activated Protein Kinases
  • AGAP2 protein, human
  • GTP-Binding Proteins