Protein arginine N-methyltransferase 9 (PRMT9)

Protein arginine N-methyltransferase 9 (PRMT9) is a type II methyltransferase that catalyzes the symmetric dimethylation of arginine residues on specific substrate proteins [UniProt: Q6P2P2]. Unlike other members of the PRMT family, PRMT9 has a highly specific substrate profile, with its primary target being the splicing factor SF3B2 (also known as SAP145) [PubMed: 25512560]. Through the methylation of SF3B2, PRMT9 serves as a critical regulator of the spliceosome, influencing alternative splicing events and mRNA maturation [PubMed: 30655515]. In the field of oncology, PRMT9 has been identified as an oncogenic driver in several cancers, such as hepatocellular carcinoma and lung adenocarcinoma, where its overexpression facilitates cell cycle progression and metastasis [PubMed: 33063745]. Consequently, PRMT9 is considered a promising therapeutic target, particularly for small molecule inhibitors aimed at disrupting its methyltransferase activity to treat splicing-dependent tumors [PubMed: 31439808]. Although selective PRMT9 inhibitors are still in the early stages of development, the target's distinct structural features compared to other PRMTs offer opportunities for high-specificity drug design [PubMed: 25512560].

Other names

PRMT10FBXO20F-box only protein 20Arginine methyltransferase 9

PRMT9 catalyzes the transfer of methyl groups from S-adenosyl-L-methionine (SAM) to the arginine residues of substrate proteins, specifically producing monomethylarginine (MMA) and symmetric dimethylarginine (sDMA).