title: Chromatin-mediated transcriptional regulation by the yeast architectural factors NHP6A and NHP6B.
abstract: The Saccharomyces cerevisiae NHP6A and NHP6B proteins are chromatin architectural factors, functionally and structurally related to the mammalian high mobility group (HMG)-1 and -2 proteins, a family of non-sequence-specific DNA binding proteins. nhp6a nhp6b mutants have various morphological defects and are defective in the induced expression of several RNA polymerase II-transcribed genes. We found that NHP6A/B proteins are also required for full induction of the yeast CHA1 gene. Importantly, CHA1 basal level expression is increased 10-fold in an nhp6a nhp6b double deletion mutant. Micrococcal nuclease and DNase I analysis of the CHA1 gene in this strain showed an open promoter structure, characteristic of the activated state of this promoter, even under non-inducing conditions. To address the possible function of the NHP6A/B proteins in chromatin-mediated gene regulation, we performed whole-genome transcriptional profiling of a Deltanhp6a Deltanhp6b yeast strain. Our results suggest that NHP6A/B proteins play an important regulatory role, repressing as well as potentiating expression of genes involved in several cellular processes, and that NHP6A/B control is exerted at the level of the individual gene.
authors: Department of Genetics, Institute of Molecular Biology, University of Copenhagen, Oster Farimagsgade 2A, DK-1353 Copenhagen K, Denmark.
authors: J M
authors: JM
authors: Moreira
authors: S
authors: S
authors: Holmberg
mesh_terms: D002843:Chromatin / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal; D016681:Genome, Fungal; D024001:HMGN Proteins; D026901:Membrane Transport Proteins / Q000235:genetics; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D028061:Phosphate Transport Proteins; D012319:RNA Polymerase II / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D014158:Transcription, Genetic
chemical_list: D002843:Chromatin; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D024001:HMGN Proteins; D026901:Membrane Transport Proteins; C086471:NHP6A protein, S cerevisiae; C086472:NHP6B protein, S cerevisiae; D009687:Nuclear Proteins; D028061:Phosphate Transport Proteins; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; C055831:phosphate permease; D012319:RNA Polymerase II