Figures & data
Figure 1. Set2-mediated H3K36 methylation and its functional consequences.(A) Set2/Rpd3S pathway. The RNAP II-associated histone methyltransferase Set2 methylates H3K36 (red circle). This mark is recognized by the Rco1 and Eaf3 subunits of the Rpd3S deacetylase complex that maintains genomic regions in a hypoacetylated state by removing acetyl marks (green circle). The arrow indicates the direction of transcription. (B) Distribution of H3K36 methylation (H3K36me), histone exchange and histone acetylation in wild-type or SET2 deleted (set2Δ) yeast strains. (C) Mechanism of Set2-mediated suppression of histone exchange. (i) Co-transcriptional methylation of H3K36 by Set2, results in (ii) preventing Asf1-mediated assembly of newly synthesized pre-acetylated histones (yellow cylinder). (iii) H3K36 methylated nucleosomes are targeted either by the Isw1b complex, or by the RNAP II-associated Chd1 remodeler, resulting in nucleosome remodeling in cis, thus allowing passage of RNAP II and preventing trans-histone exchange by Asf1. (iv) The Rpd3S deacetylase complex is targeted by H3K36 methylation to the coding regions, which is maintained in a hypoacetylated state. (v) The histone chaperone function of Rpd3S may be instrumental in the capture of H3K36 methylated histones and its reassembly following the passage of RNAP II.
