Hog1 Controls Global Reallocation of RNA Pol II upon Osmotic Shock in Saccharomyces cerevisiae

G3: Genes, Genomes, Genetics

Kristen E. Cook²  Erin K. O’Shea¹ 

[1] Howard Hughes Medical InstituteDepartment of Molecular and Cellular BiologyDepartment of Chemistry and Chemical Biology, Harvard University Faculty of Arts and Sciences Center for Systems Biology, Cambridge, Massachusetts 02138Howard Hughes Medical InstituteHoward Hughes Medical InstituteDepartment of Molecular and Cellular BiologyDepartment of Chemistry and Chemical Biology, Harvard University Faculty of Arts and Sciences Center for Systems Biology, Cambridge, Massachusetts 02138Department of Molecular and Cellular BiologyHoward Hughes Medical InstituteDepartment of Molecular and Cellular BiologyDepartment of Chemistry and Chemical Biology, Harvard University Faculty of Arts and Sciences Center for Systems Biology, Cambridge, Massachusetts 02138Department of Chemistry and Chemical Biology, Harvard University Faculty of Arts and Sciences Center for Systems Biology, Cambridge, Massachusetts 02138Howard Hughes Medical InstituteDepartment of Molecular and Cellular BiologyDepartment of Chemistry and Chemical Biology, Harvard University Faculty of Arts and Sciences Center for Systems Biology, Cambridge, Massachusetts 02138;Howard Hughes Medical InstituteDepartment of Molecular and Cellular BiologyHoward Hughes Medical InstituteHoward Hughes Medical InstituteDepartment of Molecular and Cellular BiologyDepartment of Molecular and Cellular BiologyHoward Hughes Medical InstituteDepartment of Molecular and Cellular Biology

关键词: MAP kinase;    transcription;    stress response;    osmotic shock;    Hog1;   

DOI  :  10.1534/g3.112.003251

学科分类：生物科学（综合）

来源: Genetics Society of America

【 摘 要 】

When challenged with osmotic shock, Saccharomyces cerevisiae induces hundreds of genes, despite a concurrent reduction in overall transcriptional capacity. The stress-responsive MAP kinase Hog1 activates expression of specific genes through interactions with chromatin remodeling enzymes, transcription factors, and RNA polymerase II. However, it is not clear whether Hog1 is involved more globally in modulating the cell’s transcriptional program during stress, in addition to activating specific genes. Here we show that large-scale redistribution of RNA Pol II from housekeeping to stress genes requires Hog1. We demonstrate that decreased RNA Pol II occupancy is the default outcome for highly expressed genes upon stress and that Hog1 is partially required for this effect. We find that Hog1 and RNA Pol II colocalize to open reading frames that bypass global transcriptional repression. These activation targets are specified by promoter binding of two osmotic stress-responsive transcription factors. The combination of reduced global transcription with a gene-specific override mechanism allows cells to rapidly switch their transcriptional program in response to stress.

【 授权许可】

Unknown