Exposure of cells to stress results in the rapid activation of a highly preserved family of MAP kinases, Known as SAPK (stress-activated protein kinases). The activation of MAP kinases in These response to stress, Both in mammalian p38 and Hog1 in yeast, is essential for adaptive responses Generating NECESSARY for cell survival. One of the most important Functions of the yeast Hog1 MAP kinase is to Coordinate the transcriptional program for cell survival NECESSARY Against osmotic stress.


Previously, researchers at the Pompeu Fabra University Described HAD Different Mechanisms Regulated by the Hog1 SAPK During the process of transcription initiation During osmotic stress and in the process of transcriptional elongation. In work recently published in the EMBO Journal, These researchers, in Collaboration with teams from the University of Seville, Radboud (Netherlands) and Vienna (Austria) show the Hog1 SAPK That Also controls the output of nucleosomes required for transcriptional activation in response to stress by selective recruitment of chromatin remodeler RSC complex. For efficient transcription, RNA Pol II to Overcome the Presence of nucleosomes in chromatin.


In response to stress, Hog1 SAPK complex Physically Interacts with the RSC to direct association with the direct STI ORF of osmoestrés response genes. In RSC mutants, RNA Pol II at promoters Accumulate, but not in the coding region. Also, These mutants show Reduced expression of stress response genes and sensitivity to high osmolarity increaser. These data Indicate That recruitment of RSC by Hog1 SAPK is NECESSARY to after-stress induced gene expression. Thus, regulation of gene expression mediated by MAP kinases require the modification of chromatin.