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

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.

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Excretion of the anti-sigma factor through a flagellar substructure couples flagellar gene expression with flagellar assembly in Salmonella typhimurium

MGG Molecular & General Genetics ◽

10.1007/bf00279569 ◽

1994 ◽

Vol 243 (6) ◽

pp. 605-612 ◽

Cited By ~ 123

Author(s):

Kazuhiro Kutsukake

Keyword(s):

Gene Expression ◽

Salmonella Typhimurium ◽

Sigma Factor ◽

Flagellar Gene ◽

Flagellar Assembly

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Lateral Flagellar Gene System of Vibrio parahaemolyticus

Journal of Bacteriology ◽

10.1128/jb.185.15.4508-4518.2003 ◽

2003 ◽

Vol 185 (15) ◽

pp. 4508-4518 ◽

Cited By ~ 98

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.

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

Journal of Bacteriology ◽

10.1128/jb.00884-09 ◽

2009 ◽

Vol 191 (21) ◽

pp. 6602-6611 ◽

Cited By ~ 39

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.

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Isolation and functional characterization of Spirulina D6D gene promoter: Role of a putative GntR transcription factor in transcriptional regulation of D6D gene expression

Biochemical and Biophysical Research Communications ◽

10.1016/j.bbrc.2007.11.018 ◽

2008 ◽

Vol 365 (4) ◽

pp. 643-649 ◽

Cited By ~ 10

Author(s):

Sanjukta Subudhi ◽

Pavinee Kurdrid ◽

Apiradee Hongsthong ◽

Matura Sirijuntarut ◽

Supapon Cheevadhanarak ◽

...

Keyword(s):

Gene Expression ◽

Transcription Factor ◽

Transcriptional Regulation ◽

Functional Characterization ◽

Gene Promoter

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Exploring the role of sigma factor gene expression on production by Corynebacterium glutamicum: sigma factor H and FMN as example

Frontiers in Microbiology ◽

10.3389/fmicb.2015.00740 ◽

2015 ◽

Vol 6 ◽

Cited By ~ 18

Author(s):

Hironori Taniguchi ◽

Volker F. Wendisch

Keyword(s):

Gene Expression ◽

Corynebacterium Glutamicum ◽

Sigma Factor ◽

Factor H ◽

Factor Gene

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Identification and characterization of rapidly dividing U937 clones with differential telomerase activity and gene expression profiles: role of c-Myc/Mad1 and Id/Ets proteins

Leukemia ◽

10.1038/sj.leu.2402607 ◽

2002 ◽

Vol 16 (9) ◽

pp. 1877-1880 ◽

Cited By ~ 15

Author(s):

X Xiao ◽

SK Phogat ◽

IA Sidorov ◽

J Yang ◽

I Horikawa ◽

...

Keyword(s):

Gene Expression ◽

Expression Profiles ◽

Gene Expression Profiles ◽

Telomerase Activity ◽

Ets Proteins ◽

Identification And Characterization

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A Dispensable Role for Forespore-Specific Gene Expression in Engulfment of the Forespore during Sporulation ofBacillus subtilis

Journal of Bacteriology ◽

10.1128/jb.182.10.2919-2927.2000 ◽

2000 ◽

Vol 182 (10) ◽

pp. 2919-2927 ◽

Cited By ~ 39

Author(s):

Ya-Lin Sun ◽

Marc D. Sharp ◽

Kit Pogliano

Keyword(s):

Gene Expression ◽

Transcription Factor ◽

Sigma Factor ◽

Mother Cell ◽

Spore Production ◽

Specific Gene ◽

Ofbacillus Subtilis ◽

Formation Pathway ◽

Specific Gene Expression

ABSTRACT During the stage of engulfment in the Bacillus subtilisspore formation pathway, the larger mother cell engulfs the smaller forespore. We have tested the role of forespore-specific gene expression in engulfment using two separate approaches. First, using an assay that unambiguously detects sporangia that have completed engulfment, we found that a mutant lacking the only forespore-expressed engulfment protein identified thus far, SpoIIQ, is able to efficiently complete engulfment under certain sporulation conditions. However, we have found that the mutant is defective, under all conditions, in the expression of the late-forespore-specific transcription factor ςG; thus, SpoIIQ is essential for spore production. Second, to determine if engulfment could proceed in the absence of forespore-specific gene expression, we made use of a strain in which activation of the mother cell-specific sigma factor ςE was uncoupled from forespore-specific gene expression. Remarkably, engulfment occurred in the complete absence of ςF-directed gene expression under the same conditions permissive for engulfment in the absence of SpoIIQ. Our results demonstrate that forespore-specific gene expression is not essential for engulfment, suggesting that the machinery used to move the membranes around the forespore is within the mother cell.

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Role of TonB1 in Pyoverdine-Mediated Signaling in Pseudomonas aeruginosa

Journal of Bacteriology ◽

10.1128/jb.00742-09 ◽

2009 ◽

Vol 191 (18) ◽

pp. 5634-5640 ◽

Cited By ~ 32

Author(s):

Matt Shirley ◽

Iain L. Lamont

Keyword(s):

Gene Expression ◽

Pseudomonas Aeruginosa ◽

Sigma Factor ◽

Phenylacetic Acid ◽

Cytoplasmic Membrane ◽

Receptor Protein ◽

Wild Type ◽

Membrane Spanning ◽

Signaling Process

ABSTRACT Pyoverdines are siderophores secreted by Pseudomonas aeruginosa. Uptake of ferripyoverdine in P. aeruginosa PAO1 occurs via the FpvA receptor protein and requires the energy-transducing protein TonB1. Interaction of (ferri)pyoverdine with FpvA activates pyoverdine gene expression in a signaling process involving the cytoplasmic-membrane-spanning anti-sigma factor FpvR and the sigma factor PvdS. Here, we show that mutation of a region of FpvA that interacts with TonB1 (the TonB box) prevents this signaling process, as well as inhibiting bacterial growth in the presence of the iron-chelating compound ethylenediamine-di(o-hydroxy-phenylacetic acid). Signaling via wild-type FpvA was also eliminated in strains lacking TonB1 but was unaffected in strains lacking either (or both) of two other TonB proteins in P. aeruginosa, TonB2 and TonB3. An absence of pyoverdine-mediated signaling corresponded with proteolysis of PvdS. These data show that interactions between FpvA and TonB1 are required for (ferri)pyoverdine signal transduction, as well as for ferripyoverdine transport, consistent with a mechanistic link between the signaling and transport functions of FpvA.

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Analysis of the Role of RsbV, RsbW, and RsbY in Regulating σB Activity in Bacillus cereus

Journal of Bacteriology ◽

10.1128/jb.187.16.5846-5851.2005 ◽

2005 ◽

Vol 187 (16) ◽

pp. 5846-5851 ◽

Cited By ~ 33

Author(s):

Willem van Schaik ◽

Marcel H. Tempelaars ◽

Marcel H. Zwietering ◽

Willem M. de Vos ◽

Tjakko Abee

Keyword(s):

Bacillus Cereus ◽

Sigma Factor ◽

Functional Characterization ◽

Regulatory Proteins ◽

Stress Exposure ◽

Gram Positive Bacteria ◽

Important Regulator ◽

Factor Antagonist

ABSTRACT The alternative sigma factor σB is an important regulator of the stress response of Bacillus cereus. Here, the role of the regulatory proteins RsbV, RsbW, and RsbY in regulating σB activity in B. cereus is analyzed. Functional characterization of RsbV and RsbW showed that they act as an anti-sigma factor antagonist and an anti-sigma factor, respectively. RsbW can also act as a kinase on RsbV. These data are in line with earlier functional characterizations of RsbV and RsbW homologs in B. subtilis. The rsbY gene is unique to B. cereus and its closest relatives and is predicted to encode a protein with an N-terminal CheY domain and a C-terminal PP2C domain. In an rsbY deletion mutant, the σB response upon stress exposure was almost completely abolished, but the response could be restored by complementation with full-length rsbY. Expression analysis showed that rsbY is transcribed from both a σA-dependent promoter and a σB-dependent promoter. The central role of RsbY in regulating the activity of σB indicates that in B. cereus, the σB activation pathway is markedly different from that in other gram-positive bacteria.

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