Interaction characterization of new proteins with the exosome

Abstract

The RNA exosome is a ribonucleolytic complex formed by the association of differentsubunits. Because of its exoribonuclease 3'à5' catalytic activity, the exosome controls thelevels of all classes of RNAs, regulating the chromatin structure, gene expression, celldifferentiation and ribosome biogenesis. In this context, this RNase has been the main focus ofresearch in our laboratory. The exosome requires cofactors for its role in different RNAprocessing reactions that can act directly in the catalytic activity of the exosome or in thecomplex targeting to its substrates. However, the mechanisms involved in these processes havenot been completely elucidated. Therefore, various studies indicate that the phosphorylation ofexosome subunits and its cofactors are important for the signaling regulation between theexosome components and its cofactors. This project aims to characterize the phosphoproteinsYLR257W and YLR363W-A, which were identified in their phosphorylated forms wheninteracting with exosome subunits in previous studies of our lab. To achieve these aims, co-immunoprecipitation assays will be performed for both proteins of Saccharomyces cerevisiaeand the identification of proteins will be performed by mass spectrometry. These approachescan potentially generate unprecedented results and identify yet unreported proteins that interactwith the exosome, as well as examine their role in the cell functions. Given the evolutionaryconservation of these processes in eukaryotes, these results can be extrapolated to humans, inwhich diseases have already been identified as being caused by mutations in the genes oforthologous proteins studied by our research group.