IQUIBICEN   23947
INSTITUTO DE QUIMICA BIOLOGICA DE LA FACULTAD DE CIENCIAS EXACTAS Y NATURALES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Transcription regulation of PKA subunits in Saccharomyces cerevisiae under heat shock
Autor/es:
PAUTASSO, C; CAÑONERO, L; ROSSI, S
Lugar:
Mendoza
Reunión:
Congreso; XLVIII Reunión Anual de la Sociedad Argentina de Bioquímica y Biología Molecular (SAIB); 2012
Institución organizadora:
SAIB
Resumen:
Yeast respond to environmental changes by transduction cascades
that in general allow regulating gene expression. The aim of this
work is to contribute to the knowledge of thecAMP/PKApathway in S.cerevisiae, studying the expression regulation of PKA catalytic
and regulatory subunits, TPK1, TPK2 and TPK3, and BCY1, under
stress conditions. Using TPKs-LacZ and BCY1-LacZ fusion genes,
we found that the activity level of TPK1 and TPK3 promoters
occurred near the diaxic-shift. In contrast, TPK2 and BCY1
promoters activities were higher at the beginning of the log phase.
We also demonstrated that there is a mechanism of negative
autoregulation on PKA subunits expression that involves a PKA
signaling in an isoform specific way. Under heat and saline stress
conditions TPK1 showed an increment in its promoter activity,
while TPK2, TPK3 and BCY1 remained constant. Studies with
several deletion mutants involved in the stress signal transduction
pathway showed differences among promoters. TPK1 and BCY1
were positively regulated by Rim15 and Gis1, TPK1 was also
positively regulated by Yak1 and Msn2/4. Results of ChIP assays
showed the presence of Msn2 and Gis1, in the TPK1 promoter
transcriptionally active.Any of these factors are regulators of TPK2
and TPK3 promoters. These results were confirmed by mRNAs
quantification.