PRMT5-mediated methylation of histone H4R3 recruits DNMT3A, coupling histone and DNA methylation in gene silencing

Mammalian gene silencing is associated with both histone and DNA methylation. The PRMT5 arginine histone methyltransferase is now found to affect DNA methylation at the γ-globin locus in mice. This is mediated by an effect on recruitment of the DNA methyltransferase DNMT3A, but through interaction with the product of PRMT5 activity. This suggests that DNMT3A reads the histone methylation, coupling it to nearby DNA methylation.