Nitrosative Stress Response in Vibrio cholerae: Role of S-Nitrosoglutathione Reductase

Abstract

Vibrio cholerae, the causative agent of cholera, poses serious threats to humans worldwide. V. cholerae faces host inflammatory response and encounters nitrosative stress before establishing successful colonization. It is not clear how V. cholerae combats nitric oxide and reactive nitrogen species. In the present study, we used three clinical strains of V. cholerae and tested their nitrosative stress response pattern towards sodium nitroprusside (SNP) and S-Nitrosoglutathione (GSNO). Among them, V. cholerae, belonging to both O1 and O139 serotypes, showed moderate resistance to SNP and GSNO. However, a V. cholerae strain belonging to non O1 and non O139 showed sensitivity to SNP but resistance towards GSNO. Reduced glutathione and glutathione reductase play a significant role to combat nitrosative stress in V. cholerae. This is the first report where we show the presence of GSNO reductase activity in V. cholerae and that it plays an important role to detoxify S-Nitrosoglutathione. GSNO reductase activity of V. cholerae was regulated by posttranslational modification through S-nitrosylation under in vitro conditions which could be reversed by dithiothreitol (DTT). In addition, we show that biofilm formation remained unaffected under nitrosative stress in V. cholerae.

Effect of Nitrosative Stress on the S-Nitroso-Proteome of Paracoccidioides brasiliensis

“…This reversibility and structural changes caused by oxidation allow signalization cascades to have a fine coordination of adaptive responses to react to endogenous and exogenous metabolic processes (Vázquez-Torres, 2012). Proteins S-nitrosylation is important to a considerable variety of mechanisms, from RNS detoxification in bacteria (Hess et al, 2005;Patra et al, 2016) and protozoa (Wang et al, 2014), to regulating cell cycle in fungi cells (Foster et al, 2009;Lee P.Y. et al, 2011;Majumdar et al, 2012) and regulating human diseases (Chung, 2015;Bradley and Steinert, 2016).…”

In-vivo protein nitration and de-nitration facilitateVibrio choleraecell survival under anaerobic condition: Consequences of Nitrite induced protein nitration

“…From these facts, we propose that in a nitrate deprived anaerobic growth condition, in-vivo nitration and de-nitration is a cyclical phenomenon which is governed by controlled oxidative condition of cell and can perform as a sole source of respiration just to keep cells viable. Apart from this, in our previous studies we showed the role of S-nitrosoglutathione Reductase (GSNOR) 21 and Catalases (KatB & KatG) 22 in combating nitrosative stress mediated by GSNO and peroxynitrite respectively. Hence, in-vivo nitration might also be an advanced evolutionary adapted mechanism of nitrosative stress tolerance found in V. cholerae , as it restricts proteome to unnecessary PTN in nitroso-oxidative stress prevailing environment such as inside human gut.…”

Molecular dissection of a dedicated formaldehyde dehydrogenase from Mycobacterium smegmatis

“…12,[22][23][24]32 Although the exact mechanism for cysteine-responsive transcriptional regulation is so far unknown, conserved cysteines may play an important role in posttranslational modifications. 33 Formaldehyde-responsive transcriptional factors such as formaldehyde activating enzyme (Fae) are found in P. denitrificans and Rhodobacter sphaeroides. 29 However, we were unable to find any such transcriptional factor in M. smegmatis.…”