Identification of regulated genes during permanent focal cerebral ischaemia: characterization of the protein kinase 9b5/MARKL1/MARK4

J Neurochem. 2004 Mar;88(5):1114-26. doi: 10.1046/j.1471-4159.2003.02228.x.

Abstract

Cerebral ischaemia induces transcriptional changes in a number of pathophysiologically important genes. Here we have systematically studied gene expression changes after 90 min and 24 h of permanent focal ischaemia in the mouse by an advanced fragment display technique (restriction-mediated differential display). We identified 56 transcriptionally altered genes, many of which provide novel hints to ischaemic pathophysiology. Particularly interesting were two pro-apoptotic genes (Grim19 and Tdag51), whose role in cerebral ischaemia and neuronal cell death has not been recognized so far. Among the unknown sequences, we identified a gene that was rapidly and transiently up-regulated. The encoded protein displayed high homology to the MARK family of serine-threonine protein kinases and has recently been described as MARKL1/MARK4. Here we demonstrate that this protein is a functional protein kinase with the ability to specifically phosphorylate a cognate peptide substrate for the AMP-kinase family. Upon overexpression in heterologous cells, the functional wild-type protein, but not its kinase-dead mutant, led to decreased cell viability. We conclude that the up-regulation of this kinase during focal ischaemia may represent an interesting new target for pharmacological intervention.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alternative Splicing
  • Amino Acid Sequence
  • Animals
  • Brain Ischemia / enzymology*
  • Brain Ischemia / genetics*
  • Cell Survival / genetics
  • Cloning, Molecular
  • Disease Models, Animal
  • Gene Expression Profiling
  • Gene Expression Regulation*
  • Mice
  • Molecular Sequence Data
  • Organ Specificity
  • Phosphorylation
  • Protein-Serine-Threonine Kinases / genetics*
  • Protein-Serine-Threonine Kinases / metabolism
  • Sequence Homology
  • Sequence Homology, Amino Acid

Substances

  • MARK3 protein, human
  • MARK4 protein, mouse
  • Protein-Serine-Threonine Kinases