Reversible protein phosphorylation is a major mechanism of post-translational protein modification and plays an important role in all life forms by regulating important and different cellular functions. Protein kinases (PK) and phosphatases (PP), the enzymes that catalyse phosphorylation and dephosphorylation reactions, are responsible of changes in enzymatic activity, cellular localisation, or binding partners of the substrates. We are far from having a complete view of the complex cell signalling pathways. Therefore it is obvious that new strategies are necessaries in order to achieve a faster development of this field. I plan to use the combination of the powerful genomics and proteomics technology together with genetics and biochemistry to study the signalling events in which protein phosphoryolation reactions are involved, using the budding yeast as a eukaryotic model. The analysis, by DNA microarrays, of the changes in the expression patters induced by deletion of non-essential PK and PP allow us the assignation of functions to those proteins. And this was the case for the studied Ptc1, a yeast PP2C. In the present application we propose a deeper study of the Ptc1 functions and the identification of the cell signalling mechanisms in which this PP takes part. We will use the DNA microarrays to identify the changes in the global expression profile induced by the lack of each regulatory subunits, both essential and not essential, of the yeast PP1 Glc7. Simultaneously we will identify PK and PP substrates using diverse proteomics approaches, such as the yeast proteome microchip or the analysis by 2D gels. Candidates to start with are the MAPK Slt2 and the PP2C Ptc1. The long term goal is still the identification of cellular roles of yeast PK and PP by using post-genomic technologies.
|Effective start/end date||1/12/07 → 30/11/09|