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In Saccharomyces cerevisiae, adaptation to hydrogen peroxide (H2O2) decreases plasma membrane permeability to H2O2, changes its lipid composition and reorganizes ergosterol-rich microdomains by a still unknown mechanism. Here we show, by a quantitative analysis of the H2O2-induced adaptation effect on the S. cerevisiae plasma membrane-enriched fraction proteome, using two-dimensional gel electrophoresis, that 44 proteins are differentially expressed. Most of these proteins were regulated at a post-transcriptional level. Fourteen of these proteins contain redox-sensitive cysteine residues and nine proteins are associated with lipid and vesicle traffic. In particular, three proteins found in eisosomes and in the eisosome-associated membrane compartment occupied by Can1p were up-regulated (Pil1p, Rfs1p and Pst2p) during adaptation to H2O2. Survival studies after exposure to lethal H2O2 doses using yeast strains bearing a gene deletion corresponding to proteins associated to lipid and vesicle traffic demonstrated for the first time that down-regulation of Kes1p, Vps4p and Ynl010wp and up-regulation of Atp1 and Atp2 increases resistance to H2O2. Moreover, for the pil1Δ strain, H2O2 at low levels produces a hormetic effect by increasing proliferation. In conclusion, these data further confirms the plasma membrane as an active cellular site during adaptation to H2O2 and shows that proteins involved in lipid and vesicle traffic are important mediators of H2O2 adaptation. [ABSTRACT FROM AUTHOR]

High sucrose consumption and sub-acute cadmium effects on δ-ALA-D activity, Na+/K+-ATPase activity, and lipid peroxidation were studied in different tissues of mice. Experimental groups were control, high sucrose (200 g/L), cadmium (5 mg/kg/day, subcutaneously, two consecutive doses in different days in each week, during 4 weeks), and sucrose plus cadmium. There was a significant increase in TBARS levels for spleen and liver in cadmium and sucrose plus cadmium groups. Testicular δ-ALA-D activity of cadmium and sucrose plus cadmium-treated animals was significantly inhibited, whereas the enzyme activity increased in blood (cadmium and sucrose plus cadmium groups) and spleen (sucrose plus cadmium group). Na+/K+-ATPase activity was significantly decreased in brain and kidney of sucrose plus cadmium-treated animals. Our data indicate that sub-acute cadmium treatment inhibits significantly testicular δ-ALA-D activity, demonstrating the prevalent cadmium effect in vivo on reproductive systems. Furthermore, high sucrose consumption and sub-acute cadmium treatment have interactive effects on cerebral and renal Na+/K+-ATPase, showing that a short-term intake of high quantity of sucrose can aggravate the toxicity of Cd2+. [Copyright &y& Elsevier]