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

Mei Zou; Kaiying Wang; Jiajun Zhao; Huifang Lu; Hui Yang; Meirong Huang; Lu Wang; Guangli Wang; Jian Huang; Xun Min

doi:10.3389/fmicb.2023.1159986

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

Front Microbiol. 2023 Apr 5:14:1159986. doi: 10.3389/fmicb.2023.1159986. eCollection 2023.

Authors

Mei Zou^{1

2}, Kaiying Wang^{1

2}, Jiajun Zhao^{1

2}, Huifang Lu^{1

2}, Hui Yang^{1

2}, Meirong Huang^{2

3}, Lu Wang^{1

2}, Guangli Wang^{1

2}, Jian Huang^{1

2}, Xun Min^{1

2}

Affiliations

¹ Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China.
² School of Laboratory Medicine, Zunyi Medical University, Zunyi, Guizhou, China.
³ Department of Blood Transfusion, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China.

Abstract

In bacteria, DegS protease functions as an activating factor of the σ^E 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 σ^E 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.

Keywords: DegS; Vibrio cholerae; chemotaxis; colonization; motility.