Kalirin-7, a protein enriched in postsynaptic density, is involved in ischemic signal transduction

Neurochem Res. 2008 Sep;33(9):1789-94. doi: 10.1007/s11064-008-9631-y. Epub 2008 Mar 13.

Abstract

Regulators of mitogen activated protein kinases (MAPK) and c-Jun N-terminal/stress-activated kinase (JNK) include Rho-like small GTP-binding proteins and their regulators. SynGAP and kalirin-7 are postsynaptic density-enriched proteins identified through their interaction with Rho GTPases and PSD-95 scaffold protein. We examined immunoreactivity of SynGAP, kalirin-7, and PSD-95, phosphorylation of MAPK and JNK in control and postischemic hippocampus in gerbil model of transient forebrain ischemia. In normal brain higher amount of kalirin-7 but a lower amount of P-JNK was found in ischemia-resistant hippocampal area: CA2-3, DG than in ischemia-vulnerable CA1. After 5 min ischemia and 1 h reperfusion a decrease of P-ERK and increase of P-JNK were uniformly observed in the hippocampal parts. By contrast, the amount of kalirin-7 in CA2-3, DG reached 56% (P < 0.001) of control while was doubled in CA1. Oppositely, the immunoreactivity of SynGAP was increased in CA2-3, DG and reduced in CA1. Our data indicate that SynGAP and kalirin-7 take part in the regulation of ischemic signal transduction but the mechanism does not seem directly connected with the activation of MAPK and JNK.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Extracellular Signal-Regulated MAP Kinases / metabolism
  • GTPase-Activating Proteins / metabolism
  • Gerbillinae
  • Guanine Nucleotide Exchange Factors / genetics
  • Guanine Nucleotide Exchange Factors / metabolism*
  • Hippocampus / metabolism
  • Ischemia / metabolism*
  • JNK Mitogen-Activated Protein Kinases / metabolism
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism*
  • Signal Transduction / physiology*

Substances

  • GTPase-Activating Proteins
  • Guanine Nucleotide Exchange Factors
  • Nerve Tissue Proteins
  • postsynaptic density proteins
  • Extracellular Signal-Regulated MAP Kinases
  • JNK Mitogen-Activated Protein Kinases