IQUIBICEN   23947
INSTITUTO DE QUIMICA BIOLOGICA DE LA FACULTAD DE CIENCIAS EXACTAS Y NATURALES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
PKA and HOG1 role on gene expression in response to osmostic stress in Saccharomyces cerevisiae
Autor/es:
PORTELA, P; ROSSI, S; OJEDA L
Lugar:
Buenos Aires
Reunión:
Congreso; LIII Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular, Reunión Conjunta de Sociedades de Biociencias; 2017
Institución organizadora:
SAIB
Resumen:
(1217) PKA AND HOG1 ROLE ON GENE EXPRESSION INRESPONSE TO OSMOSTIC STRESS IN SACCHAROMYCESCEREVISIAELucas Ojeda, Silvia Rossi, Paula PortelaDepartamento de química Biológica, FCEN, UBA/IQUIBICEN- ConicetGene expression regulation by intracellular stimulus-activatedprotein kinases are essential for cell adaptation to environmentalchanges. The transcriptional induction of most genes whose transcriptionresponds to salt stress is dependent on the association ofthe Hog1 kinase in stress-responsive genes that strongly correlateswith chromatin remodeling and increased gene expression. Previouslywe described that PKA catalytic and regulatory subunits areassociated with both coding regions and promoters of the severalosmo-responsive genes in a stress dependent manner. Particularly,Tpk2 catalytic subunit activity regulates the chromatin remodelersSnf2 (SWI/SNF complex) and Arp8 (INO80 complex) associationto promoters and coding regions to downregulate the gene expressionduring osmotic stress. Here, we focus on the interplay betweenPKA and Hog1 kinases on gene expression in response to osmoticstress. We tested for genetic interaction between TPK2 and HOG1genes for cell survival to osmotic stress. While tpk2D mutant straindid not confer sensitivity to osmotic stress, hog1D mutant strainshowed hypersensitivity to osmotic stress. The double mutant hog-1Dtpk2D displayed high tolerance to salinity suggesting that bothkinase has an opposite role in cell adaptation to osmotic stress.ChIP assays showed a correlation in the in vivo kinetic recruitmentof Tpk2 and Hog1 to HSP42 coding region and RPS29B promoterregion in response to osmotic stress, with a maximum at 5-10 minutespost-osmotic stress. We then analysed the nucleosome positioningat the promoter and coding region in the RPS29B gene byMicrococcal Nuclease (MNase) digestion of chromatin before andafter stress in wild type. We found that osmotic stress, promotes anincrease of compactness of the chromatin that correlated to downregulationof RPS29B gene expression. Our results suggest thattransient stress adaptive response could be regulated by oppositeroles of Hog1 and PKA.