PUBLICATION

Z-REX uncovers a bifurcation in function of Keap1 paralogs

Authors
Van Hall-Beauvais, A., Poganik, J.R., Huang, K.T., Parvez, S., Zhao, Y., Lin, H.Y., Liu, X., Long, M.J.C., Aye, Y.
ID
ZDB-PUB-221028-35
Date
2022
Source
eLIFE   11: (Journal)
Registered Authors
Aye, Yimon, Huang, Kuan-Ting, Poganik, Jesse
Keywords
biochemistry, chemical biology, zebrafish
MeSH Terms
  • Animals
  • Antioxidants/metabolism
  • Humans
  • Kelch-Like ECH-Associated Protein 1/genetics
  • Kelch-Like ECH-Associated Protein 1/metabolism
  • NF-E2-Related Factor 2*/genetics
  • NF-E2-Related Factor 2*/metabolism
  • Signal Transduction
  • Zebrafish*/metabolism
PubMed
36300632 Full text @ Elife
Abstract
Studying electrophile signaling is marred by difficulties in parsing changes in pathway flux attributable to on-target, vis-à-vis off-target, modifications. By combining bolus dosing, knockdown, and Z-REX-a tool investigating on-target/on-pathway electrophile signaling, we document that electrophile labeling of one zebrafish-Keap1-paralog (zKeap1b) stimulates Nrf2- driven antioxidant response (AR) signaling (like the human-ortholog). Conversely, zKeap1a is a dominant-negative regulator of electrophile-promoted Nrf2-signaling, and itself is nonpermissive for electrophile-induced Nrf2-upregulation. This behavior is recapitulated in human cells, wherein following electrophile treatment: (1) zKeap1b-transfected cells are permissive for augmented AR-signaling through reduced zKeap1b-Nrf2 binding; (2) zKeap1a-transfected cells are non-permissive for AR-upregulation, as zKeap1a-Nrf2 binding capacity remains unaltered; (3) 1:1 ZKeap1a:zKeap1b-transfected cells show no Nrf2-release from the Keap1-complex, rendering these cells unable to upregulate AR. We identified a zKeap1a-specific point-mutation (C273I) responsible for zKeap1a's behavior. Human-Keap1(C273I), of known diminished Nrf2-regulatory capacity, dominantly muted electrophile-induced Nrf2-signaling. These studies highlight divergent and interdependent electrophile signaling behaviors, despite conserved electrophile sensing.
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Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
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Mapping