title: HTL1 encodes a novel factor that interacts with the RSC chromatin remodeling complex in Saccharomyces cerevisiae.
abstract: RSC is an essential chromatin remodeling complex in Saccharomyces cerevisiae that performs central roles in transcriptional regulation and cell cycle progression. Here we identify Htl1 as a novel factor that associates with the RSC complex both physically and functionally. We isolated HTL1 through a genetic screen for mutants that displayed additive growth defects with a conditional mutation in the protein kinase C gene (PKC1), which has been suggested through genetic connections to interact functionally with RSC. Several lines of evidence connect HTL1 to RSC function. First, an htl1Delta mutant displayed temperature-sensitive growth and a G(2)/M cell cycle arrest at restrictive temperatures, a phenotype similar to that of strains with conditional mutations in essential RSC components. Second, we isolated RSC3, which encodes a component of the RSC complex, as a dosage suppressor of the htl1Delta growth arrest. Third, an htl1Delta mutant displayed additive growth defects with conditional rsc3 alleles. Fourth, overexpression of HTL1 suppressed the growth defect of a strain with a conditional mutation in another RSC component, RSC8. Finally, we demonstrate that Htl1 is a nuclear protein that can associate in vivo with a fraction of the RSC complex. We propose that an RSC-Htl1 complex acts coordinately with protein kinase C to regulate the G(2)/M transition.
authors.affiliation: Department of Biochemistry & Molecular Biology, Bloomberg School of Public Health, The Johns Hopkins University, Baltimore, Maryland 21205, USA.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Romeo
authors.forename: Melinda L
authors.initials: ML
authors.lastname: Angus-Hill
authors.forename: Andrew K
authors.initials: AK
authors.lastname: Sobering
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Kamada
authors.forename: Bradley R
authors.initials: BR
authors.lastname: Cairns
authors.forename: David E
authors.initials: DE
authors.lastname: Levin
mesh_terms: D002453:Cell Cycle / Q000502:physiology; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D002455:Cell Division; D002473:Cell Wall / Q000378:metabolism; D002843:Chromatin / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005434:Flow Cytometry; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D046911:Macromolecular Substances; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D011493:Protein Kinase C / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D013489:Suppression, Genetic; D013696:Temperature; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D018797:Cell Cycle Proteins; D002843:Chromatin; D004268:DNA-Binding Proteins; C469779:HTL1 protein, S cerevisiae; D046911:Macromolecular Substances; D009687:Nuclear Proteins; C103337:RSC complex, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D011493:Protein Kinase C