Chromatin remodeling regulation of protein kinase A TPK1 subunit in Saccharomyces cerevisiae by stress

RECA, SOL; ROSSI, SILVIA; GALELO, FIORELA

Congreso; SAIB LI; 2016

Chromatin remodeling is required for efficient transcription of eukaryotic genes. This process is performed by a large class of ATP-dependent chromatin remodeling complexes as SWI/SNF, ISWI, CHD and INO80 protein families. Yeast PKA is composed by two catalytic subunits encoded by TPK1, TPK2 and TPK3 genes, and two regulatory subunits encoded by BCY1 gene. The transcription of TPK1 is regulated in response to osmostress and heat-shock. Using MNase protection assay we demonstrate that three positioned nucleosomes reside only over the TPK1 promoter. Upon heat-shock and osmostress this nucleosomes are no longer detectable, and TPK1 is induced. Using β-galactosidase reporter assay and ChIP we demonstrate that remodeling of TPK1 chromatin structure requires SWI/SNF, INO80, and RSC during heat-shock and SWR1 during osmostress. It had been described that inositol polyphosphates can modulate the activities of several chromatin remodeling complexes. To identify additional factors important for remodeling chromatin in TPK1 promoter we analyze TPK1 promotor activity and mRNA synthesis in null mutants strains for the synthesis of soluble inositol polyphosphates pathway. TPK1 promoter activity and mRNA levels decreased in the ipk2∆, plc1∆ and ksc1∆ strains but not in the ipk1∆ strain. These results indicate that it is likely the lack of PP-IP4 production that affects the TPK1 transcription.