Kelch-like ECH-associated protein 1 (KEAP1)

Overview

KEAP1 (Kelch-like ECH-associated protein 1) is a cytoplasmic regulatory protein best known for controlling the stability of nuclear factor erythroid 2-related factor 2 (NRF2), a central transcription factor in cellular antioxidant defense. Under basal conditions, KEAP1 functions as part of a Cullin3-based ubiquitin ligase complex that promotes NRF2 degradation, thereby limiting activation of antioxidant and cytoprotective genes. When KEAP1-mediated repression is reduced, NRF2 can accumulate, translocate to the nucleus, and induce downstream protective programs such as heme oxygenase 1 (HO-1) and NAD(P)H quinone dehydrogenase 1 (NQO1).

Biomedically, KEAP1 is important because it sits at the center of the KEAP1-NRF2 axis, a pathway implicated in oxidative stress responses, ischemic injury, diabetic nephropathy, septic acute kidney injury, Parkinson’s disease-related biology, and broader context-dependent stress adaptation. Recent work also highlights that KEAP1 pathway behavior is not determined solely by mutation status; rather, pathway output can vary with cellular context, protein interactions, and post-translational regulation.

Recent Publications Summary

Recent studies have continued to place KEAP1 at the center of NRF2-regulated stress responses across cancer and nonmalignant disease models. In neuroblastoma, DMAMCL was reported to bind KEAP1 in MYCN-amplified cells, increasing nuclear NRF2 and upregulating HMOX1 to drive ferroptosis; this KEAP1-dependent mechanism contrasted with a STEAP3-mediated pathway in MYCN-nonamplified cells 42444025Jul. In metastatic non-small cell lung cancer, a real-world outcomes study specifically examined tumors with STK11 mutations, including those co-occurring with KEAP1 and KRAS mutations, to assess progression-free and overall survival, underscoring the clinical relevance of KEAP1-altered disease biology 42377736Jun. A separate review also emphasized that NRF2 pathway activity, rather than genotype alone, may better capture the functional consequences of KEAP1-axis dysregulation in NSCLC 41944556Apr.

Several publications focused on pharmacologic or natural-product activation of the KEAP1-NRF2 axis as a protective strategy against oxidative injury. Omaveloxolone increased NRF2 target proteins in SMA type I fibroblasts, where basal NRF2 pathway activity was reduced compared with controls 42301137Jun. 10-Shogaol from ginger was described as a novel NRF2 activator that inhibits KEAP1-mediated ubiquitination and proteasome degradation, thereby inducing antioxidant gene expression and reducing inflammatory signaling in dengue and Zika virus models 42270434Jun. Similarly, carvacrol was investigated in acute doxorubicin-induced cardiac injury, with the study linking its cardioprotective effects to changes in Nrf2/Keap1-related signaling and extracellular vesicle-associated MALAT1 expression 42259137Jun. Cafestol was reported to ameliorate diabetic nephropathy through activation of the Keap1-Nrf2 axis, improving renal injury, oxidative stress, inflammation, and fibrosis in a manner described as independent of glycemic control 42133719May.

Other studies extended KEAP1-related signaling to neuroprotection and tissue injury models. Poliumoside was shown to alleviate ischemic stroke injury by activating the Keap1/Nrf2 pathway, promoting Nrf2 nuclear translocation and increasing downstream antioxidant proteins including HO-1 and NQO1 42134761May. In aging-related airway epithelial cells, a mechanistic study found that phosphorylation of Cullin3 by the pseudokinase ALDH18A1 disrupted KEAP1-mediated NRF2 degradation, stabilizing NRF2 and identifying a new regulatory layer controlling KEAP1-Cullin3 ubiquitin ligase activity 41996736Apr. In addition, a peptide-design platform generated target-specific peptides for KEAP1 among other proteins, indicating ongoing interest in KEAP1 as a drug-design target 41934387Apr.

What Changes, What Holds

1. KEAP1-altered tumors still behave as functionally distinct disease states, but genotype alone is not enough to predict pathway output
REINFORCES The new cancer work does not replace the baseline account of KEAP1 as a regulator of NRF2; it sharpens the point that downstream behavior can diverge from mutation status and must be interpreted in context. The NSCLC findings and the accompanying review support using NRF2-pathway activity as a functional readout of KEAP1-axis dysregulation rather than relying only on KEAP1, STK11, or KRAS genotype 42377736Jun41944556Apr.

2. KEAP1-NRF2 activation is being used more broadly as a protective strategy, but the direction of benefit remains context dependent
REINFORCES These studies extend the established antioxidant-stress framework by showing that pharmacologic or natural-product modulation of KEAP1 can raise NRF2 target expression and reduce injury signals in several models. They do not overturn the baseline mechanism; instead, they reinforce KEAP1 as a druggable control point for cytoprotection, while also showing that the same axis is being pursued in diverse diseases and delivery contexts 42301137Jun42270434Jun.

3. KEAP1 regulation now appears to include an additional upstream control layer that can stabilize NRF2 without changing KEAP1 itself
NEW DIRECTION The airway-epithelial-cell work adds a mechanism not covered in the baseline: KEAP1-mediated NRF2 degradation can be disrupted by phosphorylation of Cullin3, implying that KEAP1 output is shaped by more than KEAP1 abundance or mutation status. That broadens the model of the KEAP1-Cullin3 ligase complex and suggests a new point of intervention, but it needs independent validation before it is folded into the core account 41996736Apr.

Overview update candidates: KEAP1 pathway activity may be better captured functionally than by genotype alone; Cullin3 phosphorylation as an upstream regulator of KEAP1-mediated NRF2 degradation.