PRMT4

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 asymmetric dimethylation of arginine residues on histones and other proteins, using S-adenosyl-L-methionine as the methyl donor.

In chromatin, PRMT4 methylates histone H3 on arginine 17 and arginine 26 (H3R17me2a and H3R26me2a), marks associated with transcriptional activation. PRMT4 also methylates non-histone substrates, including transcription factors and coactivators, and functions as a transcriptional coactivator for nuclear receptors such as the estrogen receptor and androgen receptor, often through interaction with SRC-1 family coactivators.

Biological roles include regulation of gene expression, chromatin structure, and RNA processing; involvement in development and differentiation, including myogenesis and adipogenesis; and participation in stem cell biology.

Clinical relevance: Dysregulation of PRMT4 expression or activity has been observed in several cancers, and the enzyme is studied as a potential therapeutic target. Ongoing research aims to delineate its substrate spectrum, regulation, and the impact of inhibition.