Methylation of arginine by PRMT1 regulates Nrf2 transcriptional activity during the antioxidative response

The cap 'n' collar (CNC) family of transcription factors play important roles in resistance of oxidative and electrophilic stresses. Among the CNC family members, NF-E2-related factor 2 (Nrf2) is critical for regulating the antioxidant and phase II enzymes through antioxidant response element (ARE)-mediated transactivation. The activity of Nrf2 is controlled by a variety of post-translational modifications, including phosphorylation, ubiquitination, acetylation and sumoylation. Here we demonstrate that the arginine methyltransferase-1 (PRMT1) methylates Nrf2 protein at a single residue of arginine 437, both in vitro and in vivo. Using the heme oxygenase-1 (HO-1) as a model of phase II enzyme gene, we found that methylation of Nrf2 by PRMT1 led to a moderate increase of its DNA-binding activity and transactivation, which subsequently protected cells against the tBHP-induced glutathione depletion and cell death. Collectively, our results define a novel modification of Nrf2, which operates as a fine-tuning mechanism for the transcriptional activity of Nrf2 under the oxidative stress.