Proteomic analysis of spontaneous mutants of Lactococcus lactis: Involvement of GAPDH and arginine deiminase pathway in H₂O₂ resistance

Abstract

Lactococcus lactis, one of the most commonly used dairy starters, is often subjected to oxidative stress in cheese manufacturing. A comparative proteomic analysis was performed to identify the molecular modifications responsible for the robustness of three spontaneous H(2)O(2)-resistant (SpOx) strains. In the parental strain, glyceraldehyde-3-phosphate deshydrogenase (GAPDH) activity is ensured by GapB and the second GAPDH GapA is not produced in standard growth conditions. We showed that GapA was overproduced in the highly resistant SpOx2 and SpOx3 mutants. Its overproduction in the MG1363 strain led to an increased H(2)O(2) resistance of exponential growing cells. Upon H(2)O(2) exposure, GapB was fully inactivated by oxidation in the parental strain. In SpOx mutants, it partly remained in the reduced form sustaining partially GAPDH activity. The analysis of gapA disruption in these SpOx strains indicated that additional unraveled mechanisms likely contribute to the resistance phenotype. In the SpOx1 mutant, the arginine deiminase pathway was found to be upregulated and disruption of arcA or arcB genes abolished H(2)O(2) resistance. We concluded that arginine consumption was directly responsible for the SpOx1 phenotype. Finally, these results suggest that sustaining energy supply is a major way of leading to oxidative stress resistance in L. lactis.

Loss of Antibiotic Tolerance in Sod-Deficient Mutants Is Dependent on the Energy Source and Arginine Catabolism in Enterococci

“…In Tn mutants with an upregulated ADI operon, tolerance of the Sod-deficient strain was partially restored. These results seem to support the above-mentioned oxidative-stress-based killing model, since a recent study demonstrated the direct implication of the ADI operon in the oxidative stress response of Lactococcus lactis (34). In a spontaneously H 2 O 2 -resistant mutant of this species, the ADI operon was found to be upregulated and disruption of the first (arcA) or second (arcB) gene of this operon abolished peroxide resistance.…”

The Intraperitoneal Transcriptome of the Opportunistic Pathogen Enterococcus faecalis in Mice

“…The expression of sodA is also somewhat induced in vivo (+3.2-fold). Moreover, several other genes with known or suspected implications in oxidative stress are present in the in vivo induced gene database such as genes endoding thioredoxin reductase ( ef1405 ; +4.8-fold), two members of the ferric uptake regulator family, PerR ( ef1585 ; 4.4-fold) [ 52 ] and Fur ( ef1525 ; +5.9-fold), and the Dps family protein ( ef3233 ; +2.6-fold) [ 45 ] as well as the arc operon implicated in arginine metabolism ( ef0104-ef0108 , +7.9-fold) [ 53 ] and the sufCDSUB operon involved in the assembly of Fe-S clusters ( ef2390-ef2394 ; +7.4 fold)[ 54 – 56 ].…”

Comparative proteomics illustrates the complexity of drought resistance mechanisms in two wheat (Triticum aestivum L.) cultivars under dehydration and rehydration

“…Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is responsible for the interconversion of 1,3-diphosphoglycerate and glyceraldehyde-3-phosphate, a central step in glycolysis and gluconeogenesis [55, 56]. The up-regulation of GAPDH in both two wheat cultivars can promote glucose metabolism to meet the increased substance and energy requirement for drought resistance as suggested by Rochat et al [57]. Triosephosphate isomerase (TPI) catalyzes the reversible interconversion of dihydroxyacetone phosphate and D-glyceraldehyde 3-phosphate, which is essential for efficient energy production in glycolysis [58].…”