PRMT5

Protein arginine methyltransferase 5 (PRMT5) is a type II arginine methyltransferase that catalyzes symmetric dimethylation of arginine residues on histone and non-histone substrates, thereby regulating chromatin organization, transcriptional control, and cellular development^[1][2]. PRMT5 functions as a major epigenetic regulator through symmetric methylation marks such as H3R8me2s and H4R3me2s, which influence gene expression programs and growth-regulatory pathways^[1][3]. Mechanistically, PRMT5 plays a central role in RNA processing and alternative splicing, and has been identified as a master regulator of mammalian splicing networks, linking arginine methylation to transcriptome regulation^[4][5]. Therefore, PRMT5 integrates transcriptional and post-transcriptional regulation to control cell proliferation, differentiation, survival, and genome maintenance^[1][5]. In disease settings, PRMT5 is frequently overexpressed or hyperactivated in multiple cancers, where it supports tumor cell growth, metastasis, and therapeutic resistance through regulation of oncogenic signaling, transcription, and RNA metabolism^[2][5][6]. Compared with related isoforms, PRMT5 belongs to the type II PRMT family and primarily generates symmetric dimethylarginine, whereas PRMT1 is the major type I enzyme responsible for asymmetric dimethylarginine formation, highlighting distinct but partially overlapping biological functions^[3][7]. For experimental applications, PRMT5 has emerged as a therapeutic target, and pharmacological inhibition disrupts methyltransferase-dependent signaling and splicing pathways; recent MTA-cooperative inhibitors further exploit vulnerabilities in MTAP-deleted tumors^[5][6]. These characteristics make PRMT5 an important model for studying epigenetic regulation, RNA splicing, and targeted cancer therapy^[1][4][6].