title: The Set2 methyltransferase associates with Ssn6 yet Tup1-Ssn6 repression is independent of histone methylation.
abstract: The Tup1-Ssn6 corepressor regulates the expression of diverse classes of genes in Saccharomyces cerevisiae. Chromatin is an important component of Tup1-Ssn6-mediated repression. Tup1 binds to underacetylated tails of histones H3 and H4, and requires multiple histone deacetylases for the repression. Here we examine if histone methylation, in addition to histone deacetylation, plays a role in Tup1-Ssn6 repression. We found that like other genes, Tup1-Ssn6 target genes exhibit increased levels of histone H3 lysine 4 trimethylation upon activation. However, deletion of individual or multiple histone methyltransferases and other SET-domain containing genes has no apparent effect on Tup1-Ssn6-mediated repression of a number of well-defined targets. Interestingly, we discovered that Ssn6 interacts with Set2. Although deletion of SET2 does not affect Tup1-Ssn6 repression of a number of target genes, Ssn6 may utilize Set2 in specific contexts to regulate gene repression.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Texas M.D. Anderson Cancer Center, Houston, TX 77030, USA.
authors.forename: Tamara
authors.initials: T
authors.lastname: Tripic
authors.forename: Diane G
authors.initials: DG
authors.lastname: Edmondson
authors.forename: Judith K
authors.initials: JK
authors.lastname: Davie
authors.forename: Brian D
authors.initials: BD
authors.lastname: Strahl
authors.forename: Sharon Y R
authors.initials: SY
authors.lastname: Dent
mesh_terms: D004268:DNA-Binding Proteins / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal / Q000502:physiology; D006657:Histones / Q000378:metabolism*; D008745:Methylation; D008780:Methyltransferases / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism*; D012097:Repressor Proteins / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*
chemical_list: C065455:CYC8 protein, S cerevisiae; D004268:DNA-Binding Proteins; D006657:Histones; D009687:Nuclear Proteins; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; C066502:TUP1 protein, S cerevisiae; D008780:Methyltransferases; C448996:Set2 protein, S cerevisiae