PRMT5 & MEP50

Protein arginine methyltransferase 5 (PRMT5) is a type II enzyme that catalyzes symmetric dimethylation of arginine residues on histone and non-histone proteins. It forms a hetero-octameric complex with its essential cofactor MEP50 (methylosome protein 50), which enhances its catalytic activity and substrate selectivity. The PRMT5–MEP50 complex regulates gene expression epigenetically, influences RNA splicing, and modulates signal transduction pathways. Aberrant PRMT5–MEP50 activity is linked to tumorigenesis, cardiovascular disorders, and neurodegeneration by driving dysregulated methylation patterns that favor cell proliferation and survival.