PRMT8

Protein arginine methyltransferase 8 (PRMT8) is a vertebrate-restricted type I PRMT predominantly expressed in the brain, with a unique N-terminal domain containing a myristoylation site that anchors it to the plasma membrane^[1][2]. Mechanistically, PRMT8 catalyzes asymmetric dimethylation of arginine residues on substrates such as EWS and histone H4, influencing RNA processing, chromatin regulation, and signal transduction^[3][4]. PRMT8 also exhibits phospholipase activity, hydrolyzing phosphatidylcholine into choline and phosphatidic acid, which is critical for dendritic arborization and motor coordination in Purkinje cells^[5]. Compared with its paralogue PRMT1, PRMT8 demonstrates brain-specific expression, a distinct N-terminal regulatory domain, and additional enzymatic functions including phospholipid hydrolysis^[6][7][2]. In developmental models such as zebrafish, PRMT8 knockdown leads to convergence/extension defects, abnormal neural morphology, and impaired neuronal differentiation, effects that cannot be rescued by PRMT1 alone^[7][8]. Variant-specific expression of PRMT8 in cancer cells further underscores its functional diversity and potential as a biomarker, with distinct isoforms influencing cellular proliferation and survival^[9]. The N-terminal domain also regulates enzymatic activity via automethylation and interactions with SH3 domain proteins, suggesting opportunities for experimental modulation^[10][2]. Collectively, these features position PRMT8 as a multifunctional, tissue-specific methyltransferase with implications for neural development, epigenetic regulation, and disease modeling^[11][5].