Rol de PKA en la respuesta traduccional frente a estrés térmico en Saccharomyces cerevisiae

CARLA BARRAZA; CLARA ANDREA SOLARI; FIORELLA GALLELO; MARIA PIA VALACCO; JORGE GERMAN FERNANDEZ; SILVIA ROSSI; SILVIA MORENO DE COLONNA; PAULA PORTELA

CABA

Workshop; Workshop Biología Celular y Molecular del ARN; 2018

Club de RNA de Buenos Aires

We examined PKA role in heat stress response in S. cerevisiae. Mild Heat stress promotes Tpk3, eIF4G, Pab1 and eIF4E aggregation. On the other hand, severe heat stress leads to the formation of PBs and SGs containing Tpk2, Tpk3 and translation initiation complex 48S. TPK2 or TPK3 deletion affects mRNAs translational response upon stress, including CYC1, HSP42, HSP30 and ENO2. TPK2 deletion leads to a robust translational arrest, greater SGs/PBs aggregation and a translational hypersensibility, whereas deleting TPK3 represses SGs/PBs formation, translational arrest and the response for the analyzed mRNAs. We analysed protein complexes formed under heat stress, through cuantitative label free proteomics. We identified proteins enriched exclusively in mild or severe heat stress and those share by both temperaturas. Gene Ontology analysis shows after mild heat stress an enrichment in ribosomal proteins and vesicle proteins COPI, while in sever heat stress we observed translation factors, ribosomal and RNA binding. Shared proteins between both temperatures belong to SGs/PBs component and translation factors, which do not show greater protein aggregation as stress intensity increases. Therefore, mild and severe heat stress promotes mRNPs aggregation with differential protein composition.