IQUIBICEN   23947
INSTITUTO DE QUIMICA BIOLOGICA DE LA FACULTAD DE CIENCIAS EXACTAS Y NATURALES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
PKA controls mRNA granules during quiescence and cell cycle resumption in budding yeast.
Autor/es:
CLARA SOLARI; PAULA PORTELA; MARK ASHE
Lugar:
Heidelberg, Germany.
Reunión:
Congreso; EMBO | EMBL Symposium: The Complex Life of mRNA; 2016
Institución organizadora:
EMBO | EMBL Symposium
Resumen:
Cellular proteome has to be readjusted as a response to tissue-specific differentiation programs or environmental changes. As a part of a cellular post-transcriptional regulatory mechanism, proteins and mRNAs can be stored in cytoplasmic granules, regulating their degradation, function or expression. In Saccharomyces cerevisiae, PKA is a hetero-tetramer composed of two regulatory subunits encoded by BCY1 gene, and two catalytic subunits encoded by three partially redundant genes, TPK1, TPK2 and TPK3. Recently, our results suggest that PKA connects glucose availability with the cell cycle and with the robustness of cellular translation. We analysed the in vivo localization of different mRNAs in quiescent cells, over strains carrying the m-TAG system for ENO2, PDC1, MFA2, TIF1, TDP1 and VNX1 mRNAs. These mRNAs are accumulated in 1-2 foci during quiescence. When cells are re-fed by addition of fresh medium for 30 minutes, TDP1 and VNX1 mRNAs granules are disassembled; but ENO2, PDC1, MFA2, and TIF1 mRNA granules increase to 2-6 granules per cell. The co-localization of mRNA granules and SGs or PBs presents differences between the mRNAs. We observed that Tpk2 and Tpk3 co-localize with TIF1-mRNA quiescent foci, and acquired a diffuse localization after re-feeding. PKA is involved in the design of the different mRNA patterns, as the deletions of distinct PKA catalytic subunits led to changes in mRNA localization. To assess the presence of active translation sites we performed puromycilation assay. A proportion of the puromycin-marked sites of protein synthesis overlap with both ENO2 and TIF1 mRNA granules during quiescence. After fresh medium addition, translationally active mRNA granules increase in an mRNA specific manner. Therefore, our results suggest that PKA controls mRNA granule formation; coordinating mRNA localization, storage and translation during quiescence and cell cycle resumption.