WDR77 is a component of the 20S PRMT5 (MIM 604045)-containing methyltransferase complex, which modifies specific arginines to dimethylarginines in several spliceosomal Sm proteins (see MIM 601061). This modification targets Sm proteins to the survival of motor neurons (SMN) complex (see MIM 600354) for assembly into small nuclear ribonucleoprotein core particles (Friesen et al., 2002
