In a previous study, the
Schistosoma mansoni
Rho1 protein was able to complement
Rho1 null mutant
Saccharomyces cerevisiae
cells at restrictive temperatures and under osmotic stress (low calcium concentration) better than the human homologue (
RhoA). It is known that under osmotic stress, the
S. cerevisiae Rho1 triggers two distinct pathways: activation of the membrane 1,3-b-glucan synthase enzymatic complex and activation of the protein kinase C1 signal transduction pathway, promoting the transcription of response genes. In the present work the SmRho1 protein and its mutants smrho
E97P, smrho
1L101T, and smrho
E97P, L101T were used to try to clarify the basis for the differential complementation of Rho1 knockout yeast strain by the human and
S. mansoni genes. Experiments of functional complementation in the presence of caffeine and in the presence of the osmotic regulator sorbitol were conducted. SmRho1 and its mutants showed a differential complementation of the yeast cells in the presence of caffeine, since smrho
E97P and smrho
E97P, L101T mutants showed a delay in the growth when compared to the yeast complemented with the wild type SmRho1. However, in the presence of sorbitol and caffeine the wild type SmRho1 and mutants showed a similar complementation phenotype, as they allowed yeast growth in all caffeine concentrations tested.
