Interaction of PKA with its regulated target genes in response to stress conditions

LETICIA BACCARINI; F. MARTÍNEZ MONTAÑES; SILVIA MORENO; MARKUS PROFT; PAULA PORTELA

Los Cocos, Córdoba

Simposio; First South American Spring Symposium in Signal Transduction and Molecular Medicine (SISTAM),; 2010

SISTAM

Regulation of gene expression by intracellular stimulus-activated protein kinases is essential for cell adaptation to environmental changes. Previously, has been described that protein kinase are physically associated to the target gene. There are three PKA catalytic subunits in S.cerevisiae: Tpk1, Tpk2 and Tpk3 and one regulatory subunit: Bcy1. Using ChIP-real time assay we analyzed the Bcy1, Tpk1 and Tpk2 association to 10 genes regions in response to osmotic and oxidative stresses. We found that Tpk1 and Tpk2 but not Bcy1, were found associated with transcribed regions in glucose exponentially growing cells. Upon hyperosmotic stress we detected Bcy1 association at the ORF regions with concomitant Tpk2 and Tpk1 occupancy. Differentially, we observed Tpk1 and Tpk2 dissociation after oxidative stress at the promoter regions. We did not find Bcy1 associated to chromatin in response to oxidative stress. We characterize the role of PKA on gene expression; our results suggest that PKA activity, controlled through Bcy1, is direct or indirectly involved in the transcriptional control upon stress. These findings suggest that PKA could exert a transcriptional regulation by direct (or indirect) association to chromatin in stress and in a gene region-dependent manner.