title: BUR kinase selectively regulates H3 K4 trimethylation and H2B ubiquitylation through recruitment of the PAF elongation complex.
abstract: Histone-lysine methylation is linked to transcriptional regulation and the control of epigenetic inheritance. Lysine residues can be mono-, di-, or trimethylated, and it has been suggested that each methylation state of a given lysine may impart a unique biological function. In yeast, histone H3 lysine 4 (K4) is mono-, di-, and trimethylated by the Set1 histone methyltransferase. Previous studies show that Set1 associates with RNA polymerase II and demarcates transcriptionally active genes with K4 trimethylation. To determine whether K4 trimethylation might be selectively regulated, we screened a library of yeast deletion mutants associated with transcriptional regulation and chromatin function. We identified BUR2, a cyclin for the Bur1/2 (BUR) cyclin-dependent protein kinase, as a specific regulator of K4 trimethylation. Surprisingly, BUR also regulated H2B monoubiquitylation, whereas other K4 methylation states and H3 lysine 79 (K79) methylation were unaffected. Synthetic genetic array (SGA) and transcription microarray analyses of a BUR2 mutant revealed that BUR is functionally similar to the PAF, Rad6, and Set1 complexes. These data suggest that BUR acts upstream of these factors to control their function. In support, we show that recruitment of the PAF elongation complex to genes is significantly impaired in a BUR2 deletion. Our data reveal a novel function for the BUR kinase in transcriptional regulation through the selective control of histone modifications.
authors.affiliation: Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599, USA.
authors.forename: R Nicholas
authors.initials: RN
authors.lastname: Laribee
authors.forename: Nevan J
authors.initials: NJ
authors.lastname: Krogan
authors.forename: Tiaojiang
authors.initials: T
authors.lastname: Xiao
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Shibata
authors.forename: Timothy R
authors.initials: TR
authors.lastname: Hughes
authors.forename: Jack F
authors.initials: JF
authors.lastname: Greenblatt
authors.forename: Brian D
authors.initials: BD
authors.lastname: Strahl
mesh_terms: D047369:Chromatin Immunoprecipitation; D016213:Cyclins / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D011495:Histone-Lysine N-Methyltransferase; D006657:Histones / Q000378:metabolism*; D015151:Immunoblotting; D008239:Lysine / Q000378:metabolism*; D008745:Methylation; D046228:Microarray Analysis; D009687:Nuclear Proteins / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism; D044763:Ubiquitin-Conjugating Enzymes / Q000378:metabolism; D015003:Yeasts
chemical_list: C414164:Bur2 protein, S cerevisiae; D016213:Cyclins; D004268:DNA-Binding Proteins; D006657:Histones; D009687:Nuclear Proteins; C097698:PAF1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D011495:Histone-Lysine N-Methyltransferase; C411250:SET1 protein, S cerevisiae; C471606:RAD6 protein, S cerevisiae; D044763:Ubiquitin-Conjugating Enzymes; D008239:Lysine