TFEB activates Nrf2 by repressing its E3 ubiquitin ligase DCAF11 and promoting phosphorylation of p62

Sci Rep. 2019 Oct 4;9(1):14354. doi: 10.1038/s41598-019-50877-8.

Abstract

Transcriptional factor EB (TFEB) and nuclear factor E2-related factor 2 (Nrf2) play crucial roles in the biological response against cellular stressors; however, their relationship has not yet been investigated. Here, we constructed human neuroglioma cell lines stably expressing TFEB. The expression of Nrf2-response genes, including heme oxygenase (HO)-1, glutathione-s-transferase-mu1 (GSTM1), and p62, was induced in the cell line, independent of oxidative stress. Of note, the protein level of Nrf2 was significantly increased, and its ubiquitinated fraction was reduced in stable cells compared to that in the control cells. Among E3 ubiquitin ligases known to be involved in the ubiquitination of Nrf2, DDB1 and Cullin4 associated factor 11 (DCAF11) was down-regulated at both protein and mRNA levels in stable cells, indicating that the repression of DCAF11 by TFEB may be mainly involved in the stabilization of Nrf2. In addition, the level of phosphorylated p62 at S349 was highly increased in stable cells compared to that in control cells, which could allow it to interfere with the association of Keap1 and Nrf2, thus stabilizing Nrf2. We suggest for the first time that TFEB could activate Nrf2 by increasing its stability under conditions devoid of oxidative stress.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / metabolism*
  • Cell Line, Tumor
  • Down-Regulation
  • HEK293 Cells
  • Humans
  • NF-E2-Related Factor 2 / metabolism*
  • Phosphorylation / genetics
  • Protein Stability
  • RNA-Binding Proteins / metabolism
  • Ubiquitin-Protein Ligase Complexes / genetics*
  • Ubiquitin-Protein Ligase Complexes / metabolism
  • Ubiquitination

Substances

  • Basic Helix-Loop-Helix Leucine Zipper Transcription Factors
  • NF-E2-Related Factor 2
  • NFE2L2 protein, human
  • P62 protein, human
  • RNA-Binding Proteins
  • TFEB protein, human
  • DDB1 and CUL4 associated factor 11, human
  • Ubiquitin-Protein Ligase Complexes