Tails of intrigue: phosphorylation of RNA polymerase II mediates histone methylation.

Histone lysine methylation plays a key role in the organization of chromatin structure and the regulation of gene expression. Recent studies demonstrated that the yeast Set1 and Set2 histone methyltransferases are recruited to mRNA coding regions by the PAF transcription elongation complex in a manner dependent upon the phosphorylation state of the carboxy-terminal domain of RNA polymerase II. These studies define an unexpected link between transcription elongation and histone methylation.