FIG 5.

A model for the role of Rtr1 in regulating cotranscriptional histone modifications. (Top) Ser5-P is at its highest near the 5′ end of the gene. As polymerase travels through the gene body, Ser2-P begins to increase. These modifications recruit Set2 to methylate coding region histones after the passage of RNAPII. Rtr1 dephosphorylates Ser5-P, essentially “turning off” H3K36me3 prior to the transcription termination site. (Bottom) In an rtr1Δ strain, Set2 retains its affinity for the CTD, and H3K36me3 enrichment is elevated in the coding region and the 3′ end of the gene where the histone mark continues into the transcription termination site at specific RNAPII target genes.