Paper de la proteïna fosfatasas PPZ de S. Cervisiae en la resistència a condicions d'alta salinitat.

Sometime ago our laboratory identified a pair of protein phosphatases, PPZ1 and PPZ2 that, on the basis of their estructure, defined a novel form of Ser/Thr phophatases. We demonstrated that these phosphatases are involved in the maintenance of the cell integrity and, recently, we have shown that they are also involved in the control of the efflux of sodium from the cell, in such a way that their mutation yield cells that are resistants to high concentrations of salt. Our data show that these phosphatases delineate a novel mechanism of control that might very well exist in other organisms with cell walls, as it is the case of higher plants, and reinforce the notion that phospho-dephosphorylation reactions are involved in the control of sodium tolerance in yeast cells. Our goals are: 1) to gain insight in the knowledge of the function and regulation of the PPZ1 and PPZ2 phosphatases, showing whether this mechanism can be extended to higher plants and 2) to define the interactions of these phosphatases with other cellular pathways involved in salt tolerance (particulary those involving phospho-dephosphorylation mechanisms). This knowledge could be crucial in the generation of cells able to resist conditions of severe salinity.