Methylates (mono- and asymmetric dimethylation) the guanidino nitrogens of arginyl residues in several proteins involved in DNA packaging, transcription regulation, and mRNA stability (By similarity). Recruited to promoters upon gene activation, methylates histone H3 and activates transcription via chromatin remodeling (PubMed:27676073). Positive regulator in the oxidative stress tolerance that promotes the expression of enzymes preventing oxidative stress such as APX1 and GPX1 by histone methylation (H3R17me2a). Confers tolerance to cadmium CdCl(2) and salt NaCl stresses (PubMed:27676073). L-arginyl-[protein] + 2 S-adenosyl-L-methionine = 2 H(+) + N(omega),N(omega)-dimethyl-L-arginyl-[protein] + 2 S-adenosyl-L-homocysteine Interacts with PQT3 in the nucleus. Targeted by PQT3 to degradation via 26S proteasome. Induced by proteasome inhibitor MG132 treatment (at protein level). Ubiquitinated by PQT3. Increased sensitivity to paraquat-triggered oxidative stress. Slower root elongation after cadmium ion CdCl(2) treatment. Decreased histone H3 methylation (H3R17me2a) leading to reduced levels of APX1 and GPX1. May be due to competing acceptor splice site. Belongs to the class I-like SAM-binding methyltransferase superfamily. Protein arginine N-methyltransferase family. Chimeric cDNA. Its C-terminal part is derived from gene At1g80500, which oded for an intracellular transporter.