Cell Signaling Technology

Product Pathways - Translational Control

KEAP1 (H436) Antibody #4617

Applications Reactivity Sensitivity MW (kDa) Source
W IP H M R Mk Endogenous 60-64 Rabbit

Applications Key:  W=Western Blotting  IP=Immunoprecipitation
Reactivity Key:  H=Human  M=Mouse  R=Rat  Mk=Monkey
Species cross-reactivity is determined by western blot. Species enclosed in parentheses are predicted to react based on 100% sequence homology.

Protocols

Specificity / Sensitivity

KEAP1 (H436) Antibody detects endogenous levels of total KEAP1 protein.

Source / Purification

Polyclonal antibodies are produced by immunizing animals with a synthetic peptide corresponding to residues surrounding His436 of human KEAP1 protein. Antibodies were purified by protein A and peptide affinity chromatography.

Western Blotting

Western Blotting

Western blot analysis of extracts from various cell lines using KEAP1 (H436) Antibody.

Background

The nuclear factor-like 2 (NRF2) transcriptional activator binds antioxidant response elements (ARE) of target gene promoter regions to regulate expression of oxidative stress response genes. Under basal conditions, the NRF2 inhibitor INrf2 (also called KEAP1) binds and retains NRF2 in the cytoplasm where it can be targeted for ubiquitin-mediated degradation (1). Small amounts of constitutive nuclear NRF2 maintains cellular homeostasis through regulation of basal expression of antioxidant response genes. Following oxidative or electrophilic stress, KEAP1 releases NRF2, thereby allowing the activator to translocate to the nucleus and bind to ARE-containing genes (2). The coordinated action of NRF2 and other transcription factors mediates the response to oxidative stress (3). Altered expression of NRF2 is associated with chronic obstructive pulmonary disease (COPD) (4). NRF2 activity in lung cancer cell lines directly correlates with cell proliferation rates, and inhibition of NRF2 expression by siRNA enhances anti-cancer drug-induced apoptosis (5).

The NRF2 repressor KEAP1 contains an amino terminal BTB/POZ domain and a carboxyl terminal KELCH domain (6,7). The KELCH domain is required for interacting with NRF2 and the BTB/POZ domain functions in binding Cul3 E3 ubiquitin ligase (8-10). Under normal conditions, the complex leads to the cytoplasmic sequestration and ubiquitin-mediated proteasomal degradation of NRF2. Electrophilic modification of KEAP1 leads to disassociation of the NRF2/KEAP1 complex. KEAP1 also targets the down regulation of NF-κB activity by targeting IKKβ degradation (11). Mutation of the corresponding KEAP1 gene is seen in lung cancer cases and can lead to uncontrolled activation of NRF2 (12-14).

  1. Cullinan, S.B. et al. (2004) Mol Cell Biol 24, 8477-86.
  2. Nguyen, T. et al. (2005) J Biol Chem 280, 32485-92.
  3. Jaiswal, A.K. (2004) Free Radic Biol Med 36, 1199-207.
  4. Suzuki, M. et al. (2008) Am J Respir Cell Mol Biol 39, 673-82.
  5. Homma, S. et al. (2009) Clin Cancer Res 15, 3423-32.
  6. Itoh, K. et al. (1999) Genes Dev 13, 76-86.
  7. Dhakshinamoorthy, S. and Jaiswal, A.K. (2001) Oncogene 20, 3906-17.
  8. Furukawa, M. and Xiong, Y. (2005) Mol Cell Biol 25, 162-71.
  9. Zhang, D.D. et al. (2004) Mol Cell Biol 24, 10941-53.
  10. Kobayashi, A. et al. (2004) Mol Cell Biol 24, 7130-9.
  11. Lee, D.F. et al. (2009) Mol Cell 36, 131-40.
  12. Padmanabhan, B. et al. (2006) Mol Cell 21, 689-700.
  13. Singh, A. et al. (2006) PLoS Med 3, e420.
  14. Ohta, T. et al. (2008) Cancer Res 68, 1303-9.

Application References

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Companion Products

For Research Use Only. Not For Use In Diagnostic Procedures.

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