G3: Genes, Genomes, Genetics (Nov 2018)

WDR-23 and SKN-1/Nrf2 Coordinate with the BLI-3 Dual Oxidase in Response to Iodide-Triggered Oxidative Stress

  • Zhaofa Xu,
  • Yiman Hu,
  • Yajun Deng,
  • Yutao Chen,
  • Hanqi Hua,
  • Siyu Huang,
  • Qian Nie,
  • Qian Pan,
  • Dengke K. Ma,
  • Long Ma

DOI
https://doi.org/10.1534/g3.118.200586
Journal volume & issue
Vol. 8, no. 11
pp. 3515 – 3527

Abstract

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Animals utilize conserved mechanisms to regulate oxidative stress. The C. elegans SKN-1 protein is homologous to the vertebrate Nrf (NF-E2-related factor) family of cap ’n’ collar (CnC) transcription factors and functions as a core regulator of xenobiotic and oxidative stress responses. The WD40 repeat-containing protein WDR-23 is a key negative regulator of SKN-1 activity. We previously found that the oxidative stress induced by excess iodide can be relieved by loss of function in the BLI-3/TSP-15/DOXA-1 dual oxidase complex. To further understand the molecular mechanism of this process, we screened for new mutants that can survive in excess iodide and identified gain-of-function mutations in skn-1 and loss-of-function mutations in wdr-23. The SKN-1C isoform functions in the hypodermis to affect animal’s response to excess iodide, while the SKN-1A isoform appears to play a minor role. wdr-23(lf) can interact with bli-3 mutations in a manner different from skn-1(gf). Transcriptome studies suggest that excess iodide causes developmental arrest largely independent of changes in gene expression, and wdr-23(lf) could affect the expression of a subset of genes by a mechanism different from SKN-1 activation. We propose that WDR-23 and SKN-1 coordinate with the BLI-3/TSP-15/DOXA-1 dual oxidase complex in response to iodide-triggered oxidative stress.

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