An RNA polymerase II- and AGO4-associated protein acts in RNA-directed DNA methylation

DNA methylation is an important epigenetic mark in many eukaryotes. In Arabidopsis plants, small interfering RNAs bound to the Argonaute 4 (AGO4) protein can direct de novo DNA methylation and consequent gene silencing. Here, a new regulator of RNA-directed DNA methylation has been discovered. This protein, RDM1, is proposed to bind to methylated DNA and to function in the AGO4 effector complex.