Fig. 4: Nitrite activates VbrK and inhibits exsC and T3SS1 gene expression. | Nature Communications

Fig. 4: Nitrite activates VbrK and inhibits exsC and T3SS1 gene expression.

From: S-nitrosylation-mediated activation of a histidine kinase represses the type 3 secretion system and promotes virulence of an enteric pathogen

Fig. 4

a Phosphorylation analysis of VbrK in ΔvbrK:pvbrK_6xHis cultured in the presence of indicated chemicals (shown on the right panel). Protein samples were separated in Phos-tag gel (upper panel) and regular gel (lower panel) and blotted with anti-His antibody. b Analysis of VbrR phosphorylation in ΔvbrR:pvbrR_6xHis cultured in the presence of nitrite or nitrate (500 μM). Protein samples were separated in Phos-tag gel (upper panel) and regular gel (lower panel) and blotted with anti-His antibody. c Quantitative RT-PCR analysis of exsC in the indicated strains. Bars represent relative expression of exsC compared to that in WT in the absence of nitrite. All error bars represent mean ± standard deviation (n = 3 biologically independent experiments). Quantitative RT-PCR analysis of vopD1 (d), vp1662 (e), and vopS (vp1686) (f) in the indicated strains. Bars represent relative expression of vopD1, vp1662, and vopS compared to the respective genes in WT in the absence of nitrite. All error bars represent mean ± standard deviation (n = 3 biologically independent experiments). c–f Statistical significance was calculated using two-tailed multiple t test with Bonferroni correction. Asterisks indicate P values *P < 0.05, **P < 0.005, and ***P < 0.0005 (exact P value for each comparison was shown in the figures).

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