Scaffolding protein that specifically recognizes and binds dimethylarginine-containing proteins. Plays a role in the regulation of translation of target mRNAs by binding Arg/Gly-rich motifs (GAR) in dimethylarginine-containing proteins. In nucleus, acts as a coactivator: recognizes and binds asymmetric dimethylation on the core histone tails associated with transcriptional activation (H3R17me2a and H4R3me2a) and recruits proteins at these arginine-methylated loci. In cytoplasm, acts as an antiviral factor that participates in the assembly of stress granules together with G3BP1