Control of transcription by the stress activated Hog1 kinase

A fundamental property of living cells is the ability to sense and robustly respond to fluctuations in their environment. In budding yeast (Saccharomyces cerevisiae) changes in extracellular osmolarity are sensed by the HOG pathway, which evokes the program for cell adaptation required for cell surv...

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Detalles Bibliográficos
Autor: Nadal Ribelles, Mariona
Tipo de recurso: tesis doctoral
Estado:Versión publicada
Fecha de publicación:2013
País:España
Institución:CBUC, CESCA
Repositorio:TDR. Tesis Doctorales en Red
OAI Identifier:oai:www.tdx.cat:10803/293257
Acceso en línea:http://hdl.handle.net/10803/293257
Access Level:acceso abierto
Palabra clave:Gene expression
Chromatin remodeling
Hog1 MAPK
Osmostress
Tling arrays
Expressió gènica
Remodelació de cromatina
Estrés osmòtic
RNA no codificant
575
Descripción
Sumario:A fundamental property of living cells is the ability to sense and robustly respond to fluctuations in their environment. In budding yeast (Saccharomyces cerevisiae) changes in extracellular osmolarity are sensed by the HOG pathway, which evokes the program for cell adaptation required for cell survival. The aim of this thesis was to further characterize the molecular mechanisms by which Hog1 regulates gene expression upon osmostress. A genome-wide genetic screen lead to the identification of several activities required for regulation of gene expression. Here we describe the characterization of a novel substrate for the SAPK whose activity is required for proper transcription initiation and elongation in response to stress. This thesis also aimed to globally characterize the role of Hog1 in reprogramming the transcriptome of S. cerevisiae under osmostress conditions. By the combination of molecular approaches coupled to genome-wide techniques (ChIP-seq, MNase-seq and Tiling arrays) we have been able to fully characterize the localization of the key components that drive osmoresponsive transcription, providing for the first time a complete picture of the transcription process. The high resolution of the genome-wide approaches, has allowed us to identify new transcriptional roles for the SAPK such as the targeting of RNA Pol III machinery, and the regulation of a novel class of functional long noncoding RNAs (lncRNA). In summary, results presented in this thesis provide novel insights into the mechanisms by which the Hog1 SAPK modulates gene expression.