Identifier: TFG:2126
Authors: Tinoco Gil, Natàlia
Abstract:
Protein phosphatase type Z 1 (Ppz1) is found only in fungi. This phosphatase plays an important role in osmotic and saline tolerance, participates in the maintenance of the cell wall and in addition, it is involved in the progression of the cell cycle. It has been observed that its overexpression is toxic to Sacharomyces cerevisiae, thus, it is thought that its deregulation could be a good target for new antifungal therapies. Until today, only two inhibitors of this phosphatase have been described, Hal3 and Vhs3. In this work, the objective was to characterize Vhs2 as a suppressor of the toxicity derived from overexpression of Ppz1 as well as to create two different mutants of VHS2 in order to analyze if the phosphorylation/dephosphorylation of the protein has any effect on recovery of the toxic phenotype caused by Ppz1 overexpression. Firstly, through recombinant DNA technology, two mutated versions of VHS2 were created, in which Serine 314 was replaced by Alanina and Aspartic, thus mermining a dephosphorylation and a phosphorylation of the protein, respectively. Subsequently, growth trials were carried out in which it was reported that strains overexpressing Vhs2 were able to reverse toxicity more effectively than wild type strains but not in the same way that the strains that overexpress Hal3. In addition, in these same trials it was also revealed that there were no differences between the phenotypes of the two Vhs2 mutants studied during the project. Finally, the results of the immunoblotting studies suggested that the overexpression of Ppz1 causes the increase in expression levels of Vhs2. However, no direct relationship was found between the expression levels of both proteins.
Repositori URV