Proteome analysis of erythrocytes lacking AMP-activated protein kinase reveals a role of PAK2 kinase in eryptosis

J Proteome Res. 2011 Apr 1;10(4):1690-7. doi: 10.1021/pr101004j. Epub 2011 Feb 22.


Activation of AMP-activated protein kinase (AMPK) upon energy depletion stimulates energy production and limits energy utilization. Erythrocytes lacking AMPK are susceptible to suicidal cell death (eryptosis). A hallmark of eryptosis is cell membrane scrambling with phosphatidylserine exposure at the erythrocyte surface, which can be identified from annexin V-binding. AMPKα1-deficient mice (ampk(-/-)) suffer from anemia due to accelerated clearance of erythrocytes from circulating blood. To determine the link between AMPK and the eryptotic phenotype, we performed a global proteome analysis of erythrocytes from ampk(-/-) mice and wild-type mice using high-accuracy mass spectrometry and label-free quantitation and measured changes of expression levels of 812 proteins. Notably, the p21-activated kinase 2 (PAK2), previously implicated in apoptosis, was detected as downregulated in erythrocytes of ampk(-/-) mice, pointing to its potential role in eryptosis. To validate this, we showed that specific inactivation of PAK2 with the inhibitor IPA3 in human and murine ampk(+/+) erythrocytes increases the binding of annexin V and augments the stimulating effect of glucose deprivation on annexin V-binding. Inhibition of PAK2 failed to significantly modify annexin V-binding in ampk(-/-) erythrocytes, showing that AMPK and PAK2 exert similar phenotypes upon inactivation in erythrocytes. This study presents the first large-scale analysis of protein expression in erythrocytes from AMPKα1-deficient mice and reveals a role of PAK2 kinase in eryptosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • AMP-Activated Protein Kinases / genetics
  • AMP-Activated Protein Kinases / metabolism*
  • Animals
  • Cell Death / physiology*
  • Erythrocytes / chemistry*
  • Erythrocytes / enzymology*
  • Erythrocytes / physiology*
  • Humans
  • Mass Spectrometry / methods
  • Mice
  • Mice, Knockout
  • Proteome / analysis*
  • Proteomics / methods
  • p21-Activated Kinases / genetics
  • p21-Activated Kinases / metabolism*


  • Proteome
  • p21-Activated Kinases
  • AMP-Activated Protein Kinases