PRMT4CARM1

PRMT4, also known as CARM1 (coactivator-associated arginine methyltransferase 1), is a member of the protein arginine methyltransferase (PRMT) family. It is a type I PRMT that catalyzes the asymmetric dimethylation of arginine residues, using S-adenosyl-L-methionine as the methyl donor. The enzyme mainly targets histone tails, with histone H3 arginine 17 and arginine 26 (H3R17me2a and H3R26me2a) being well-characterized substrates, a modification that influences chromatin structure and transcriptional activity. Beyond histones, CARM1 also methylates several non-histone proteins involved in transcriptional regulation.

Functionally, PRMT4/CARM1 serves as a transcriptional coactivator. It associates with nuclear hormone receptors and other transcription factors, integrating chromatin modification with transcriptional activation. It is typically incorporated into multi-protein coactivator complexes that recruit additional chromatin-modifying enzymes to promoter regions, thereby facilitating gene expression in response to hormonal and developmental cues.

Biological roles of PRMT4/CARM1 include embryonic development and cellular differentiation, with documented involvement in adipogenesis and myogenesis in various model systems. It also participates in signaling pathways that regulate hormone-responsive gene expression, including estrogen receptor–mediated transcription.

Clinical and research relevance: altered PRMT4/CARM1 expression or activity has been observed in several cancers and other diseases, reflecting its role in transcriptional regulation and chromatin dynamics. Because of its central position in coactivator complexes and histone methylation, PRMT4/CARM1 is studied as a potential therapeutic target for modulating gene expression programs in disease contexts.