Overexpression of 14-3-3ζ Increases Brain Levels of C/EBP Homologous Protein CHOP

J Mol Neurosci. 2015 Jun;56(2):255-62. doi: 10.1007/s12031-015-0510-0. Epub 2015 Feb 18.

Abstract

Recent studies demonstrated that overexpression of the molecular chaperone 14-3-3ζ protects the brain against endoplasmic reticulum (ER) stress and prolonged seizures. The 14-3-3 targets responsible for improved neuronal survival after seizures remain unknown. Here we explored the mechanism, finding that protein levels of the ER-stress-associated transcription factor C/EBP homologous protein (CHOP) were significantly higher in 14-3-3ζ-overexpressing mice. Since previous studies by us demonstrated that loss of CHOP increased vulnerability to seizure damage, we explored whether elevated CHOP levels result from 14-3-3ζ overexpression and contribute to the protection. Pull-down experiments suggested that 14-3-3ζ could bind CHOP as well as sequester a CHOP-targeting microRNA. However, 14-3-3ζ overexpression remained protective against seizure-induced hippocampal injury in mice lacking CHOP. These studies reveal a novel function for 14-3-3ζ in regulating CHOP levels but show that this is not required for protection against seizure-induced neuronal death.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 14-3-3 Proteins / genetics
  • 14-3-3 Proteins / metabolism*
  • Animals
  • Hippocampus / metabolism*
  • Mice
  • Mice, Inbred C57BL
  • MicroRNAs / metabolism
  • Protein Binding
  • Status Epilepticus / metabolism*
  • Transcription Factor CHOP / genetics
  • Transcription Factor CHOP / metabolism*

Substances

  • 14-3-3 Proteins
  • 14-3-3zeta protein, mouse
  • Ddit3 protein, mouse
  • MicroRNAs
  • Transcription Factor CHOP