title: Hog1 bypasses stress-mediated down-regulation of transcription by RNA polymerase II redistribution and chromatin remodeling.
abstract: BACKGROUND
  Cells are subjected to dramatic changes of gene expression upon environmental changes. Stress causes a general down-regulation of gene expression together with the induction of a set of stress-responsive genes. The p38-related stress-activated protein kinase Hog1 is an important regulator of transcription upon osmostress in yeast.
  
  
  RESULTS
  Genome-wide localization studies of RNA polymerase II (RNA Pol II) and Hog1 showed that stress induced major changes in RNA Pol II localization, with a shift toward stress-responsive genes relative to housekeeping genes. RNA Pol II relocalization required Hog1, which was also localized to stress-responsive loci. In addition to RNA Pol II-bound genes, Hog1 also localized to RNA polymerase III-bound genes, pointing to a wider role for Hog1 in transcriptional control than initially expected. Interestingly, an increasing association of Hog1 with stress-responsive genes was strongly correlated with chromatin remodeling and increased gene expression. Remarkably, MNase-Seq analysis showed that although chromatin structure was not significantly altered at a genome-wide level in response to stress, there was pronounced chromatin remodeling for those genes that displayed Hog1 association.
  
  
  CONCLUSIONS
  Hog1 serves to bypass the general down-regulation of gene expression that occurs in response to osmostress, and does so both by targeting RNA Pol II machinery and by inducing chromatin remodeling at stress-responsive loci.
authors.forename: Mariona
authors.initials: M
authors.lastname: Nadal-Ribelles
authors.forename: Núria
authors.initials: N
authors.lastname: Conde
authors.forename: Oscar
authors.initials: O
authors.lastname: Flores
authors.forename: Juan
authors.initials: J
authors.lastname: González-Vallinas
authors.forename: Eduardo
authors.initials: E
authors.lastname: Eyras
authors.forename: Modesto
authors.initials: M
authors.lastname: Orozco
authors.forename: Eulàlia
authors.initials: E
authors.lastname: de Nadal
authors.forename: Francesc
authors.initials: F
authors.lastname: Posas
mesh_terms: D042002:Chromatin Assembly and Disassembly; D004271:DNA, Fungal / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D012319:RNA Polymerase II / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D017422:Sequence Analysis, DNA / Q000379:methods; D013312:Stress, Physiological; D014158:Transcription, Genetic
chemical_list: D004271:DNA, Fungal; D029701:Saccharomyces cerevisiae Proteins; C088589:HOG1 protein, S cerevisiae; D020928:Mitogen-Activated Protein Kinases; D012319:RNA Polymerase II