scholarly journals Lateral Flagellar Gene System of Vibrio parahaemolyticus

2003 ◽  
Vol 185 (15) ◽  
pp. 4508-4518 ◽  
Author(s):  
Bonnie J. Stewart ◽  
Linda L. McCarter
Keyword(s):  
Gene Expression ◽  
Vibrio Parahaemolyticus ◽  
Enteric Bacteria ◽  
Transcriptional Analysis ◽  
Polar Flagellum ◽  
Flagellar Gene ◽  
Gene Encoding ◽  
Flagellar Motors ◽  
Flagellar Biosynthesis

ABSTRACT Vibrio parahaemolyticus possesses dual flagellar systems adapted for movement under different circumstances. A single polar flagellum propels the bacterium in liquid (i.e., swimming) with a motor that is powered by the sodium motive force. Multiple proton-driven lateral flagella enable translocation over surfaces (i.e., swarming). The polar flagellum is produced continuously, while production of lateral flagella is induced when the organism is grown on surfaces. This work describes the isolation of mutants with insertions in the structural and regulatory laf genes. A Tn5-based lux transcriptional reporter transposon was constructed and used for mutagenesis and subsequent transcriptional analysis of the laf regulon. Twenty-nine independent insertions were distributed within 16 laf genes. DNA sequence analysis identified 38 laf genes in two loci. Among the mutants isolated, 11 contained surface-induced lux fusions. A hierarchy of laf gene expression was established following characterization of the laf::lux transcriptional fusion strains and by mutational and primer extension analyses of the laf regulon. The laf system is like many enteric systems in that it is a proton-driven, peritrichous flagellar system; however, laf regulation was different from the Salmonella-Escherichia coli paradigm. There is no apparent flhDC counterpart that encodes master regulators known to control flagellar biosynthesis and swarming in many enteric bacteria. A potential σ54-dependent regulator, LafK, was demonstrated to control expression of early genes, and a lateral-specific σ28 factor controls late flagellar gene expression. Another notable feature was the discovery of a gene encoding a MotY-like product, which previously had been associated only with the architecture of sodium-type polar flagellar motors.

scholarly journals FliZ Is a Posttranslational Activator of FlhD4C2-Dependent Flagellar Gene Expression

2008 ◽  
Vol 190 (14) ◽  
pp. 4979-4988 ◽  
Author(s):  
Supreet Saini ◽  
Jonathon D. Brown ◽  
Phillip D. Aldridge ◽  
Christopher V. Rao
Keyword(s):  
Gene Expression ◽  
Sigma Factor ◽  
Flagellar Gene ◽  
Critical Aspect ◽  
Swarming Motility ◽  
Flagellar Biosynthesis ◽  
Serovar Typhimurium ◽  
Flagellar Assembly

ABSTRACT Flagellar assembly proceeds in a sequential manner, beginning at the base and concluding with the filament. A critical aspect of assembly is that gene expression is coupled to assembly. When cells transition from a nonflagellated to a flagellated state, gene expression is sequential, reflecting the manner in which the flagellum is made. A key mechanism for establishing this temporal hierarchy is the σ28-FlgM checkpoint, which couples the expression of late flagellar (Pclass3) genes to the completion of the hook-basal body. In this work, we investigated the role of FliZ in coupling middle flagellar (Pclass2) gene expression to assembly in Salmonella enterica serovar Typhimurium. We demonstrate that FliZ is an FlhD4C2-dependent activator of Pclass2/middle gene expression. Our results suggest that FliZ regulates the concentration of FlhD4C2 posttranslationally. We also demonstrate that FliZ functions independently of the flagellum-specific sigma factor σ28 and the filament-cap chaperone/FlhD4C2 inhibitor FliT. Furthermore, we show that the previously described ability of σ28 to activate Pclass2/middle gene expression is, in fact, due to FliZ, as both are expressed from the same overlapping Pclass2 and Pclass3 promoters at the fliAZY locus. We conclude by discussing the role of FliZ regulation with respect to flagellar biosynthesis based on our characterization of gene expression and FliZ's role in swimming and swarming motility.

scholarly journals Analysis of the Polar Flagellar Gene System ofVibrio parahaemolyticus

2000 ◽  
Vol 182 (13) ◽  
pp. 3693-3704 ◽  
Author(s):  
Yun-Kyeong Kim ◽  
Linda L. McCarter
Keyword(s):  
Gene Expression ◽  
Caulobacter Crescentus ◽  
Regulation Of Gene Expression ◽  
Enteric Bacteria ◽  
Polar Flagellum ◽  
Flagellar Gene ◽  
Swarmer Cell ◽  
Gene System ◽  
Genotypic Analysis ◽  
Insight Into

ABSTRACT Vibrio parahaemolyticus has dual flagellar systems adapted for locomotion under different circumstances. A single, sheathed polar flagellum propels the swimmer cell in liquid environments. Numerous unsheathed lateral flagella move the swarmer cell over surfaces. The polar flagellum is produced continuously, whereas the synthesis of lateral flagella is induced under conditions that impede the function of the polar flagellum, e.g., in viscous environments or on surfaces. Thus, the organism possesses two large gene networks that orchestrate polar and lateral flagellar gene expression and assembly. In addition, the polar flagellum functions as a mechanosensor controlling lateral gene expression. In order to gain insight into the genetic circuitry controlling motility and surface sensing, we have sought to define the polar flagellar gene system. The hierarchy of regulation appears to be different from the polar system of Caulobacter crescentus or the peritrichous system of enteric bacteria but is pertinent to many Vibrio andPseudomonas species. The gene identity and organization of 60 potential flagellar and chemotaxis genes are described. Conserved sequences are defined for two classes of polar flagellar promoters. Phenotypic and genotypic analysis of mutant strains with defects in swimming motility coupled with primer extension analysis of flagellar and chemotaxis transcription provides insight into the polar flagellar organelle, its assembly, and regulation of gene expression.

scholarly journals FlhF and Its GTPase Activity Are Required for Distinct Processes in Flagellar Gene Regulation and Biosynthesis in Campylobacter jejuni

2009 ◽  
Vol 191 (21) ◽  
pp. 6602-6611 ◽  
Author(s):  
Murat Balaban ◽  
Stephanie N. Joslin ◽  
David R. Hendrixson
Keyword(s):  
Gene Expression ◽  
Gene Regulation ◽  
Campylobacter Jejuni ◽  
Regulatory System ◽  
Flagellar Gene ◽  
Gtpase Activity ◽  
Gtp Hydrolysis ◽  
Genetic Analyses ◽  
Flagellar Biosynthesis ◽  
Two Component

ABSTRACT FlhF proteins are putative GTPases that are often necessary for one or more steps in flagellar organelle development in polarly flagellated bacteria. In Campylobacter jejuni, FlhF is required for σ54-dependent flagellar gene expression and flagellar biosynthesis, but how FlhF influences these processes is unknown. Furthermore, the GTPase activity of any FlhF protein and the requirement of this speculated activity for steps in flagellar biosynthesis remain uncharacterized. We show here that C. jejuni FlhF hydrolyzes GTP, indicating that these proteins are GTPases. C. jejuni mutants producing FlhF proteins with reduced GTPase activity were not severely defective for σ54-dependent flagellar gene expression, unlike a mutant lacking FlhF. Instead, these mutants had a propensity to lack flagella or produce flagella in improper numbers or at nonpolar locations, indicating that GTP hydrolysis by FlhF is required for proper flagellar biosynthesis. Additional studies focused on elucidating a possible role for FlhF in σ54-dependent flagellar gene expression were conducted. These studies revealed that FlhF does not influence production of or signaling between the flagellar export apparatus and the FlgSR two-component regulatory system to activate σ54. Instead, our data suggest that FlhF functions in an independent pathway that converges with or works downstream of the flagellar export apparatus-FlgSR pathway to influence σ54-dependent gene expression. This study provides corroborative biochemical and genetic analyses suggesting that different activities of the C. jejuni FlhF GTPase are required for distinct steps in flagellar gene expression and biosynthesis. Our findings are likely applicable to many polarly flagellated bacteria that utilize FlhF in flagellar biosynthesis processes.

scholarly journals vpaH, a Gene Encoding a Novel Histone-Like Nucleoid Structure-Like Protein That Was Possibly Horizontally Acquired, Regulates the Biogenesis of Lateral Flagella in trh-Positive Vibrio parahaemolyticus TH3996

2005 ◽  
Vol 73 (9) ◽  
pp. 5754-5761 ◽  
Author(s):  
Kwon-Sam Park ◽  
Michiko Arita ◽  
Tetsuya Iida ◽  
Takeshi Honda
Keyword(s):  
Biofilm Formation ◽  
Vibrio Parahaemolyticus ◽  
Type Strain ◽  
Wild Type Strain ◽  
Enteric Bacteria ◽  
Wild Type ◽  
Gene Encoding ◽  
Lateral Flagellum ◽  
Global Gene Regulation ◽  
Nucleoid Structure

ABSTRACT A histone-like nucleoid structure (H-NS) is a major component of the bacterial nucleoid and plays a crucial role in the global gene regulation of enteric bacteria. Here, we cloned and characterized the gene for the H-NS-like protein VpaH in Vibrio parahaemolyticus. vpaH encodes a protein of 134 amino acids that shows approximately 55%, 54%, and 41% identities with VicH in Vibrio cholerae, H-NS in V. parahaemolyticus, and H-NS in Escherichia coli, respectively. The vpaH gene was found in only trh-positive V. parahaemolyticus strains and not in Kanagawa-positive or in trh-negative environmental strains. Moreover, the G+C content of the vpaH gene was 38.6%, which is lower than the average G+C content of the whole genome of this bacterium (45.4%). These data suggest that vpaH was transmitted to trh-possessing V. parahaemolyticus strains by lateral transfer. The vpaH gene was located about 2.6 kb downstream of the trh gene, in the convergent direction of the trh transcription. An in-frame deletion mutant of vpaH lacked motility on semisolid motility assay plates. Western blot analysis and electron microscopy observations revealed that the mutant was deficient in lateral flagella biogenesis, whereas there was no defect in the expression of polar flagella. Additionally, the vpaH mutant showed a decreased adherence to HeLa cells and a decrease in biofilm formation compared with the wild-type strain. Introduction of the vpaH gene in the vpaH-negative strain increased the expression of lateral flagella compared with the wild-type strain. In conclusion, our findings suggest that VpaH affects lateral flagellum biogenesis in trh-positive V. parahaemolyticus strain TH3996.

scholarly journals ScrG, a GGDEF-EAL Protein, Participates in Regulating Swarming and Sticking in Vibrio parahaemolyticus

2007 ◽  
Vol 189 (11) ◽  
pp. 4094-4107 ◽  
Author(s):  
Yun-Kyeong Kim ◽  
Linda L. McCarter
Keyword(s):  
Gene Expression ◽  
Biofilm Formation ◽  
Vibrio Parahaemolyticus ◽  
Capsular Polysaccharide ◽  
Colony Morphology ◽  
Flagellar Gene ◽  
Surface Mobility ◽  
New Gene ◽  
Synthesis And Degradation

ABSTRACT In this work, we describe a new gene controlling lateral flagellar gene expression. The gene encodes ScrG, a protein containing GGDEF and EAL domains. This is the second GGDEF-EAL-encoding locus determined to be involved in the regulation of swarming: the first was previously characterized and named scrABC (for “swarming and capsular polysaccharide regulation”). GGDEF and EAL domain-containing proteins participate in the synthesis and degradation of the nucleotide signal cyclic di-GMP (c-di-GMP) in many bacteria. Overexpression of scrG was sufficient to induce lateral flagellar gene expression in liquid, decrease biofilm formation, decrease cps gene expression, and suppress the ΔscrABC phenotype. Removal of its EAL domain reversed ScrG activity, converting ScrG to an inhibitor of swarming and activator of cps expression. Overexpression of scrG decreased the intensity of a 32P-labeled nucleotide spot comigrating with c-di-GMP standard, whereas overexpression of scrG Δ EAL enhanced the intensity of the spot. Mutants with defects in scrG showed altered swarming and lateral flagellin production and colony morphology (but not swimming motility); furthermore, mutation of two GGDEF-EAL-encoding loci (scrG and scrABC) produced cumulative effects on swarming, lateral flagellar gene expression, lateral flagellin production and colony morphology. Mutant analysis supports the assignment of the primary in vivo activity of ScrG to acting as a phosphodiesterase. The data are consistent with a model in which multiple GGDEF-EAL proteins can influence the cellular nucleotide pool: a low concentration of c-di-GMP favors surface mobility, whereas high levels of this nucleotide promote a more adhesive Vibrio parahaemolyticus cell type.

scholarly journals Molecular Characterization of a Senescence-Associated Gene Encoding Cysteine Proteinase and its Gene Expression during Leaf Senescence in Sweet Potato

2002 ◽  
Vol 43 (9) ◽  
pp. 984-991 ◽  
Author(s):  
Guan-Hong Chen ◽  
Lin-Tzu Huang ◽  
Mee-Ngan Yap ◽  
Ruey-Hua Lee ◽  
Yih-Jong Huang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Molecular Characterization ◽  
Sweet Potato ◽  
Leaf Senescence ◽  
Cysteine Proteinase ◽  
Gene Encoding ◽  
Its Gene

scholarly journals Analysis of the Lateral Flagellar Gene System of Aeromonas hydrophila AH-3

2006 ◽  
Vol 188 (3) ◽  
pp. 852-862 ◽  
Author(s):  
Rocío Canals ◽  
Maria Altarriba ◽  
Silvia Vilches ◽  
Gavin Horsburgh ◽  
Jonathan G. Shaw ◽  
...  
Keyword(s):  
Aeromonas Hydrophila ◽  
Biofilm Formation ◽  
Vibrio Parahaemolyticus ◽  
Culture Conditions ◽  
Polar Flagellum ◽  
Flagellar Gene ◽  
Structural Genes ◽  
Colonization Factor ◽  
Accessory Factor ◽  
First Time

ABSTRACT Mesophilic Aeromonas strains express a polar flagellum in all culture conditions, and certain strains produce lateral flagella on semisolid media or on surfaces. Although Aeromonas lateral flagella have been described as a colonization factor, little is known about their organization and expression. Here we characterized the complete lateral flagellar gene cluster of Aeromonas hydrophila AH-3 containing 38 genes, 9 of which (lafA-U) have been reported previously. Among the flgL L and lafA structural genes we found a modification accessory factor gene (maf-5) that is involved in formation of lateral flagella; this is the first time that such a gene has been described for lateral flagellar gene systems. All Aeromonas lateral flagellar genes were located in a unique chromosomal region, in contrast to Vibrio parahaemolyticus, in which the analogous genes are distributed in two different chromosomal regions. In A. hydrophila mutations in flhA L, lafK, fliJ L, flgN L, flgE L, and maf-5 resulted in a loss of lateral flagella and reductions in adherence and biofilm formation, but they did not affect polar flagellum synthesis. Furthermore, we also cloned and sequenced the A. hydrophila AH-3 alternative sigma factor σ54 (rpoN); mutation of this factor suggested that it is involved in expression of both types of flagella.

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