Interference of flagellar rotation up-regulates the expression of small RNA contributing to Bordetella pertussis infection

Abstract

Bacterial small RNAs (sRNAs) posttranscriptionally regulate gene expressions involved in various biological processes, including pathogenicity. Our previous study identified sRNAs, the expression of which was up-regulated in Bordetella pertussis , the causative agent of whooping cough, upon tracheal colonization of the bacteria; however, their roles in bacterial infection remain unknown. Here, we found that one sRNA, Bpr4, contributes to B. pertussis infection by posttranscriptionally up-regulating filamentous hemagglutinin (FHA), a major adhesin of the bacteria. Bpr4 bound to the 5′ untranslated region of fhaB mRNA encoding FHA and inhibited its degradation mediated by RNaseE. Our results demonstrated that Bpr4 up-regulation was triggered by the interference of flagellar rotation, which caused the disengagement of MotA, a flagellar stator. Subsequently, MotA activated a diguanylate cyclase to generate cyclic di-GMP, which plays a role in Bpr4 up-regulation through the RisK/RisA two-component system. Our findings indicate that a flagellum-triggered sensory system contributes to B. pertussis infection.

Role of the Putative Histidine Kinase BP1092 in Bordetella pertussis Virulence Regulation and Intracellular Survival

“…Accordingly, we and others have recently provided evidence of the involvement of the post-transcriptional regulator Hfq and small noncoding regulatory RNAs in B. pertussis virulence. , …”

T3SS chaperone of the CesT family is required for secretion of the anti-sigma factor BtrA in Bordetella pertussis

“…As shown in Figure 4 A, unlike the control strain RB50, neither the mutant nor the wt strain were motile in our assay. Next, we tested two B. pertussis strains that have already been shown to be motile, namely the UT-25 isolate [ 43 ] and strain 18323 [ 44 ], however, also these B. pertussis strains were non-motile in contrast to B. bronchiseptica ( Figure 4 A). Finally, we tested the motility of all five strains according to another protocol [ 44 ].…”

“…Alternatively, motility was determined as described by Hiramatsu et al . [ 44 ]. B. pertussis and B. bronchiseptica cultures grown in SSM were washed, diluted to OD 600 of 1.0 in Hanks’ balanced salt solution (Sigma-Aldrich) containing 20 mM Hepes (pH 7.4) and 0.1% BSA, and incubated at 37°C for 1 h. One microliter of bacterial suspensions was then stabbed into motility agar based on BGA (0.45% potato infusion powder, 0.55% NaCl, 1% casein hydrolysate, 1% glycerol, 1% BSA, and 0.4% agar).…”

RpoN (sigma factor 54) contributes to bacterial fitness during tracheal colonization of Bordetella bronchiseptica

“…The recovered bacteria were diluted to an OD 650 value of 1.0 in 50 µL of PBS, mixed with 10 µL of sixfold concentrated SDS sample loading buffer, boiled for 5 min, and subjected to SDS‐PAGE followed by electrotransfer to a polyvinylidene difluoride membrane (Millipore Billerica). The western blotting was performed with rabbit anti‐FtsZ 15 (1:5000) or mouse anti‐FliC serum prepared by immunization with recombinant FliC prepared previously 16 (1:5000) as the first antibody and goat anti‐rabbit IgG‐HRP (Jackson ImmunoResearch, 111‐035‐144) or goat anti‐mouse IgG‐HRP (Jackson ImmunoResearch, 115‐035‐003) as the second antibody. The target proteins were visualized by enhanced chemiluminescence using an Immobilon Western (Merck Millipore, WBKLS0500) and LAS‐4000 mini Luminescent Image Analyzer (GE Healthcare).…”