Phosphorylation of phase-separated p62 bodies by ULK1 activates a redox-independent stress response

EMBO J. 2023 Jul 17;42(14):e113349. doi: 10.15252/embj.2022113349. Epub 2023 Jun 12.


NRF2 is a transcription factor responsible for antioxidant stress responses that is usually regulated in a redox-dependent manner. p62 bodies formed by liquid-liquid phase separation contain Ser349-phosphorylated p62, which participates in the redox-independent activation of NRF2. However, the regulatory mechanism and physiological significance of p62 phosphorylation remain unclear. Here, we identify ULK1 as a kinase responsible for the phosphorylation of p62. ULK1 colocalizes with p62 bodies, directly interacting with p62. ULK1-dependent phosphorylation of p62 allows KEAP1 to be retained within p62 bodies, thus activating NRF2. p62S351E/+ mice are phosphomimetic knock-in mice in which Ser351, corresponding to human Ser349, is replaced by Glu. These mice, but not their phosphodefective p62S351A/S351A counterparts, exhibit NRF2 hyperactivation and growth retardation. This retardation is caused by malnutrition and dehydration due to obstruction of the esophagus and forestomach secondary to hyperkeratosis, a phenotype also observed in systemic Keap1-knockout mice. Our results expand our understanding of the physiological importance of the redox-independent NRF2 activation pathway and provide new insights into the role of phase separation in this process.

Keywords: KEAP1; NRF2/NFE2L2; ULK1; liquid-liquid phase separation; p62/SQSTM1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autophagy / physiology
  • Autophagy-Related Protein-1 Homolog / genetics
  • Autophagy-Related Protein-1 Homolog / metabolism
  • Humans
  • Intracellular Signaling Peptides and Proteins / genetics
  • Intracellular Signaling Peptides and Proteins / metabolism
  • Kelch-Like ECH-Associated Protein 1 / genetics
  • Kelch-Like ECH-Associated Protein 1 / metabolism
  • Mice
  • NF-E2-Related Factor 2* / genetics
  • NF-E2-Related Factor 2* / metabolism
  • Oxidation-Reduction
  • Oxidative Stress*
  • Phosphorylation
  • Sequestosome-1 Protein / genetics


  • Kelch-Like ECH-Associated Protein 1
  • Sequestosome-1 Protein
  • NF-E2-Related Factor 2
  • ULK1 protein, human
  • Autophagy-Related Protein-1 Homolog
  • Intracellular Signaling Peptides and Proteins