Activation of SKN-1 by novel kinases in Caenorhabditis elegans

Free Radic Biol Med. 2007 Dec 1;43(11):1560-6. doi: 10.1016/j.freeradbiomed.2007.08.025. Epub 2007 Sep 7.

Abstract

Here we use a large-scale RNAi suppression screen to identify additional kinases playing a role in the activation of SKN-1 in response to oxidative stress. The SKN-1 transcription factor specifies cell fate of the EMS blastomere at the four-cell stage in the nematode Caenorhabditis elegans and also directs transcription of many genes responding to oxidative stress, including glutathione S-transferase, NAD(P)H:quinone oxidoreductase, and superoxide dismutase. SKN-1 localizes to the nucleus and directs transcription following exposure to paraquat, heat, hyperbaric oxygen, and sodium azide. Previous studies have identified GSK-3 as an inhibitor of SKN-1 nuclear localization, in the absence of stress, and PMK-1 as an activator of SKN-1 during periods of oxidative stress. Through this screen we have identified four kinases, MKK-4, IKK epsilon-1, NEKL-2, and PDHK-2, which are necessary for the nuclear localization of SKN-1 in response to oxidative stress. Inhibition of two of these kinases results in shorter life span and increased sensitivity to stress.

MeSH terms

  • Active Transport, Cell Nucleus
  • Animals
  • Caenorhabditis elegans / enzymology
  • Caenorhabditis elegans / metabolism*
  • Caenorhabditis elegans Proteins / metabolism*
  • Cell Nucleus / metabolism*
  • DNA-Binding Proteins / metabolism*
  • I-kappa B Kinase / metabolism
  • Longevity
  • Oxidative Stress*
  • Phosphotransferases / metabolism*
  • RNA Interference
  • Transcription Factors / metabolism*

Substances

  • Caenorhabditis elegans Proteins
  • DNA-Binding Proteins
  • Transcription Factors
  • skn-1 protein, C elegans
  • Phosphotransferases
  • I-kappa B Kinase