Methylates (mono- and asymmetric dimethylation) the guanidino nitrogens of arginyl residues in proteins. May methylate histone H3 at 'Arg-17' and activate transcription via chromatin remodeling. Coordinates ecdysone-mediated expression of cell death genes. L-arginyl-[protein] + 2 S-adenosyl-L-methionine = 2 H(+) + N(omega),N(omega)-dimethyl-L-arginyl-[protein] + 2 S-adenosyl-L-homocysteine Homodimer (By similarity). Interacts with EcR. Present ubiquitously (at protein level). Expressed in the imaginal disks and in larval brains, and to a much lesser degree in the polytene larval tissue such as salivary glands. Expression is high in early embryos, reduced in late embryonic and larval stages, up-regulated at the early prepupal stage and then reduced until the adult stage where it is again up-regulated. The dimethylated protein is the major form. Belongs to the class I-like SAM-binding methyltransferase superfamily. Protein arginine N-methyltransferase family.