Bernstein, BradleyHumphrey, E. L.Erlich, RSchneider, R.Bouman, P.Liu, JunKouzarides, T.Schreiber, Stuart2016-05-162002Bernstein, B. E., E. L. Humphrey, R. L. Erlich, R. Schneider, P. Bouman, J. S. Liu, T. Kouzarides, and S. L. Schreiber. 2002. “Methylation of Histone H3 Lys 4 in Coding Regions of Active Genes.” Proceedings of the National Academy of Sciences 99 (13) (June 11): 8695–8700. doi:10.1073/pnas.082249499.0027-8424http://nrs.harvard.edu/urn-3:HUL.InstRepos:27002728Posttranslational modifications of histone tails regulate chromatin structure and transcription. Here we present global analyses of histone acetylation and histone H3 Lys 4 methylation patterns in yeast. We observe a significant correlation between acetylation of histones H3 and H4 in promoter regions and transcriptional activity. In contrast, we find that dimethylation of histone H3 Lys 4 in coding regions correlates with transcriptional activity. The histone methyltransferase Set1 is required to maintain expression of these active, promoter-acetylated, and coding region-methylated genes. Global comparisons reveal that genomic regions deacetylated by the yeast enzymes Rpd3 and Hda1 overlap extensively with Lys 4 hypo- but not hypermethylated regions. In the context of recent studies showing that Lys 4 methylation precludes histone deacetylase recruitment, we conclude that Set1 facilitates transcription, in part, by protecting active coding regions from deacetylation.en-USJournal Article2016-05-1610.1073/pnas.082249499