DegS protease regulates the motility, chemotaxis, and colonization of Vibrio cholerae

Abstract

In bacteria, DegS protease functions as an activating factor of the σE envelope stress response system, which ultimately activates the transcription of stress response genes in the cytoplasm. On the basis of high-throughput RNA sequencing, we have previously found that degS knockout inhibits the expression of flagellum synthesis- and chemotaxis-related genes, thereby indicating that DegS may be involved in the regulation of V. cholerae motility. In this study, we examined the relationships between DegS and motility in V. cholerae. Swimming motility and chemotaxis assays revealed that degS or rpoE deletion promotes a substantial reduction in the motility and chemotaxis of V. cholerae, whereas these activities were restored in ΔdegS::degS and ΔdegSΔrseA strains, indicating that DegS is partially dependent on σE to positively regulate V. cholerae activity. Gene-act network analysis revealed that the cAMP–CRP–RpoS signaling pathway, which plays an important role in flagellar synthesis, is significantly inhibited in ΔdegS mutants, whereas in response to the overexpression of cyaA/crp and rpoS in the ΔdegS strain, the motility and chemotaxis of the ΔdegS + cyaA/crp and ΔdegS + rpoS strains were partially restored compared with the ΔdegS strain. We further demonstrated that transcription levels of the flagellar regulatory gene flhF are regulated by DegS via the cAMP–CRP–RpoS signaling pathway. Overexpression of the flhF gene in the ΔdegS strain partially restored motility and chemotaxis. In addition, suckling mouse intestinal colonization experiments indicated that the ΔdegS and ΔrpoE strains were characterized by the poor colonization of mouse intestines, whereas colonization efficacy was restored in the ΔdegSΔrseA, ΔdegS + cyaA/crp, ΔdegS + rpoS, and ΔdegS + flhF strains. Collectively, our findings indicate that DegS regulates the motility and chemotaxis of V. cholerae via the cAMP–CRP–RpoS–FlhF pathway, thereby influencing the colonization of suckling mouse intestines.

DegS protease regulates antioxidant capacity and adaptability to oxidative stress environment in Vibrio cholerae

“…Compared with the NAC-group, the ability of the DdegS, DrpoE, and DrpoS strains to colonize the mouse intestine could be partially restored after the reduction of oxidative stress in the NAC+ group, but not to a level close to that of the wild-type, suggesting that adaptation to the oxidative stress environment is only a part of the V. cholerae's ability to colonize the intestine. The main reason for this is that in NAC untreated, the DdegS, DrpoE, and DrpoS mutant strains significantly reduced V. cholerae's ability to colonize the mice intestine, which is in agreement with our previous findings (Zou et al, 2023). However, in the present study, we also found that with and without NAC treatment, WT, DdegS:: degS, DdegSDrseA, DdegS+ pBAD24-rpoS, and DdegS+ pBAD24-xthA strains did not differ significantly in their ability to colonize the gut.…”

“…Compared with the NAC untreated group, the colonization ability of the ΔdegS strain increased after NAC treatment, while there was no significant difference in the colonization ability of the ΔdegS +pBAD24- xthA strain, suggesting that the diminished colonization ability of the ΔdegS strain was only partially affected by the oxidative stress environment. XthA overexpression could eliminate the influence of oxidative stress, and could not revert to the influence of other factors, including motility, chemotaxis on intestinal colonization ( Zou et al., 2023 ).The differences with the Davies study may be due to the different strains we used and the different mice models.…”

“…The cAMP-CRP-RpoS pathway plays an essential role in oxidative stress in Salmonella (Cheng and Sun, 2009). Our previous results showed that DegS regulated V.cholerae motility and chemotaxis via cAMP-CRP-RpoS-FlhF pathway (Zou et al, 2023).In the present study, we investigated the effect of DegS on the antioxidant capacity of V.cholerae. Our results show that DegS regulates the expression of the nucleic acid exonuclease III gene xthA through the cAMP-CRP-RpoS pathway, thereby affecting the antioxidant capacity of V.cholerae.…”

The Response Regulator VC1795 of Vibrio Pathogenicity Island-2 Contributes to Intestinal Colonization by Vibrio cholerae

“…In addition, many studies have also found that cAMP-CRP could affect the virulence and colonization of V. cholerae through different regulatory ways. For example, according to Zou M. et al, DegS regulates V. cholerae's chemotaxis and motility through the cAMP-CRP-RpoS-FlhF pathway, which has an impact on the colonization of suckling mice intestines [28]. Muzhingi I et al demonstrated that V. cholerae controls the pathogenicity of interactions with arthropod hosts via the activity of the two-component CrbS/R system and cAMP-CRP activates the expression of the crbS and crbR genes [29].…”

Tregs depletion aggravates activation of astrocytes by modulating IL-10/GXP4 following cerebral infarction

“…The “ggplot2” R package was utilized to create a volcano plot, which illustrates the results. Furthermore, the “pheatmap” R package was employed to perform a bidirectional hierarchical clustering analysis of the collected DEGs (Xiantao tool, www.xiantao.com ) ( 12 ).…”