scholarly journals T-POP Array Identifies EcnR and PefI-SrgD as Novel Regulators of Flagellar Gene Expression

2008 ◽  
Vol 191 (5) ◽  
pp. 1498-1508 ◽  
Author(s):  
Christopher E. Wozniak ◽  
Changhan Lee ◽  
Kelly T. Hughes
Keyword(s):  
Gene Expression ◽  
Regulatory Network ◽  
Regulatory Genes ◽  
Flagellar Gene ◽  
Transcriptional Fusion ◽  
Factor Gene ◽  
Class 1 ◽  
Chromosomal Loci ◽  
Complex Regulatory Network ◽  
Flagellar Genes

ABSTRACT The T-POP transposon was employed in a general screen for tetracycline (Tet)-induced chromosomal loci that exhibited Tet-activated or Tet-repressed expression of a fliC-lac transcriptional fusion. Insertions that activated flagellar transcription were located in flagellar genes. T-POP insertions that exhibited Tet-dependent fliC-lac inhibition were isolated upstream of the ecnR, fimZ, pefI-srgD, rcsB, and ydiV genes and in the flagellar gene flgA, which is located upstream of the anti-σ28 factor gene flgM. When expressed from the chromosomal P araBAD promoter, EcnR, FimZ, PefI-SrgD, and RcsB inhibited the transcription of the flagellar class 1 flhDC operon. YdiV, which is weakly homologous to EAL domain proteins involved in cyclic-di-GMP regulation, appears to act at a step after class 1 transcription. By using a series of deletions of the regulatory genes to try to disrupt each pathway, these regulators were found to act largely independently of one another. These results identify EcnR and PefI-SrgD as additional components of the complex regulatory network controlling flagellar expression.

scholarly journals Role of Integration Host Factor in the Transcriptional Activation of Flagellar Gene Expression in Caulobacter crescentus

2005 ◽  
Vol 187 (3) ◽  
pp. 949-960 ◽  
Author(s):  
Rachel E. Muir ◽  
James W. Gober
Keyword(s):  
Gene Expression ◽  
Caulobacter Crescentus ◽  
Consensus Sequence ◽  
Integration Host Factor ◽  
Host Factor ◽  
Flagellar Gene ◽  
Class Iii ◽  
Mild Defect ◽  
Flagellar Genes ◽  
Class Iv

ABSTRACT In the Caulobacter crescentus predivisional cell, class III and IV flagellar genes, encoding the extracytoplasmic components of the flagellum, are transcribed in the nascent swarmer compartment. This asymmetric expression pattern is attributable to the compartmentalized activity of the σ54-dependent transcriptional activator FlbD. Additionally, these temporally transcribed flagellar promoters possess a consensus sequence for the DNA-binding protein integration host factor (IHF), located between the upstream FlbD binding site and the promoter sequences. Here, we deleted the C. crescentus gene encoding the β-subunit of the IHF, ihfB (himD), and examined the effect on flagellar gene expression. The ΔihfB strain exhibited a mild defect in cell morphology and impaired motility. Using flagellar promoter reporter fusions, we observed that expression levels of a subset of class III flagellar promoters were decreased by the loss of IHF. However, one of these promoters, fliK-lacZ, exhibited a wild-type cell cycle-regulated pattern of expression in the absence of IHF. Thus, IHF is required for maximal transcription of several late flagellar genes. The ΔihfB strain was found to express significantly reduced amounts of the class IV flagellin, FljL, as a consequence of reduced transcriptional activity. Our results indicate that the motility defect exhibited by the ΔihfB strain is most likely attributable to its failure to accumulate the class IV-encoded 27-kDa flagellin subunit, FljL.

scholarly journals New class of transcription factors controls flagellar assembly by recruiting RNA polymerase II in Chlamydomonas

2018 ◽  
Vol 115 (17) ◽  
pp. 4435-4440 ◽  
Author(s):  
Lili Li ◽  
Guangmei Tian ◽  
Hai Peng ◽  
Dan Meng ◽  
Liang Wang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Transcriptional Regulation ◽  
Transcription Factors ◽  
Rna Polymerase Ii ◽  
Flagellar Gene ◽  
Pol Ii ◽  
Biochemical Function ◽  
Flagellar Assembly ◽  
Flagellar Genes

Cells have developed regulatory mechanisms that underlie flagellar assembly and maintenance, including the transcriptional regulation of flagellar genes, an initial step for making flagella. Although transcriptional regulation of flagellar gene expression is required for flagellar assembly in Chlamydomonas, no transcription factor that regulates the transcription of flagellar genes has been identified. We report that X chromosome-associated protein 5 (XAP5) acts as a transcription factor to regulate flagellar assembly in Chlamydomonas. While XAP5 proteins are evolutionarily conserved across diverse organisms and play vital roles in diverse biological processes, nothing is known about the biochemical function of any member of this important protein family. Our data show that loss of XAP5 leads to defects in flagellar assembly. Posttranslational modifications of XAP5 track flagellar length during flagellar assembly, suggesting that cells possess a feedback system that modulates modifications to XAP5. Notably, XAP5 regulates flagellar gene expression via directly binding to a motif containing a CTGGGGTG-core. Furthermore, recruitment of RNA polymerase II (Pol II) machinery for transcriptional activation depends on the activities of XAP5. Our data demonstrate that, through recruitment of Pol II, XAP5 defines a class of transcription factors for transcriptional regulation of ciliary genes. This work provides insights into the biochemical function of the XAP5 family and the fundamental biology of the flagellar assembly, which enhance our understanding of the signaling and functions of flagella.

scholarly journals TraM of plasmid R1 controls transfer gene expression as an integrated control element in a complex regulatory network

1997 ◽  
Vol 25 (3) ◽  
pp. 495-507 ◽  
Author(s):  
Elisabeth Pölzleitner ◽  
Ellen L. Zechner ◽  
Wilfried Renner ◽  
Rainer Fratte ◽  
Bettina Jauk ◽  
...  
Keyword(s):  
Gene Expression ◽  
Regulatory Network ◽  
Integrated Control ◽  
Control Element ◽  
Transfer Gene ◽  
Plasmid R1 ◽  
Complex Regulatory Network

scholarly journals Response Regulator DegU of Listeria monocytogenes Controls Temperature-Responsive Flagellar Gene Expression in Its Unphosphorylated State

2008 ◽  
Vol 190 (13) ◽  
pp. 4777-4781 ◽  
Author(s):  
Norman Mauder ◽  
Tatjana Williams ◽  
Frederike Fritsch ◽  
Michael Kuhn ◽  
Dagmar Beier
Keyword(s):  
Gene Expression ◽  
Listeria Monocytogenes ◽  
Transcriptional Control ◽  
Ethanol Tolerance ◽  
Response Regulator ◽  
Phosphorylation Site ◽  
Flagellar Gene ◽  
Temperature Responsive ◽  
Receiver Domain ◽  
Flagellar Genes

ABSTRACT We demonstrate that in Listeria monocytogenes, temperature-responsive transcriptional control of flagellar genes does not rely on the phosphorylation of the conserved phosphorylation site (D55) in the receiver domain of response regulator DegU. Furthermore, proper control of DegU-regulated genes involved in ethanol tolerance and virulence is independent of receiver phosphorylation.

scholarly journals Cross-Regulation in Vibrio parahaemolyticus: Compensatory Activation of Polar Flagellar Genes by the Lateral Flagellar Regulator LafK

2004 ◽  
Vol 186 (12) ◽  
pp. 4014-4018 ◽  
Author(s):  
Yun-Kyeong Kim ◽  
Linda L. McCarter
Keyword(s):  
Gene Expression ◽  
Pseudomonas Aeruginosa ◽  
Vibrio Cholerae ◽  
Vibrio Parahaemolyticus ◽  
Gene Organization ◽  
Flagellar Gene ◽  
Flagellar Genes

ABSTRACT Gene organization and hierarchical regulation of the polar flagellar genes of Vibrio parahaemolyticus, Vibrio cholerae, and Pseudomonas aeruginosa appear highly similar, with one puzzling difference. Two σ54-dependent regulators are required to direct different classes of intermediate flagellar gene expression in V. cholerae and P. aeruginosa, whereas the V. parahaemolyticus homolog of one of these regulators, FlaK, appears dispensable. Here we demonstrate that there is compensatory activation of polar flagellar genes by the lateral flagellar regulator LafK.

scholarly journals Capture, amplification, and global profiling of microRNAs from low quantities of whole cell lysate

The Analyst ◽  
2017 ◽  
Vol 142 (17) ◽  
pp. 3203-3211 ◽  
Author(s):  
Nayi Wang ◽  
Jijun Cheng ◽  
Rong Fan ◽  
Jun Lu
Keyword(s):  
Gene Expression ◽  
Regulatory Network ◽  
Transcriptional Level ◽  
Control Gene ◽  
Whole Cell Lysate ◽  
Cell Lysate ◽  
Control Gene Expression ◽  
Genome Wide ◽  
Non Coding Rnas ◽  
Complex Regulatory Network

MicroRNAs (miRNAs) are small non-coding RNAs that control gene expression at the post-transcriptional levelviaa complex regulatory network that requires genome-wide miRNA profiling to dissect.

scholarly journals Two Tandem Mechanisms Control Bimodal Expression of the Flagellar Genes in Salmonella enterica

2020 ◽  
Vol 202 (13) ◽  
Author(s):  
Xiaoyi Wang ◽  
Santosh Koirala ◽  
Phillip D. Aldridge ◽  
Christopher V. Rao
Keyword(s):  
Gene Expression ◽  
Salmonella Enterica ◽  
Feedback Loop ◽  
Growth Conditions ◽  
Double Negative ◽  
Flagellar Gene ◽  
Content Type ◽  
Motile Cells ◽  
Flagellar Assembly ◽  
Flagellar Genes

ABSTRACT Flagellar gene expression is bimodal in Salmonella enterica. Under certain growth conditions, some cells express the flagellar genes whereas others do not. This results in mixed populations of motile and nonmotile cells. In the present study, we found that two independent mechanisms control bimodal expression of the flagellar genes. One was previously found to result from a double negative-feedback loop involving the flagellar regulators RflP and FliZ. This feedback loop governs bimodal expression of class 2 genes. In this work, a second mechanism was found to govern bimodal expression of class 3 genes. In particular, class 3 gene expression is still bimodal, even when class 2 gene expression is not. Using a combination of experimental and modeling approaches, we found that class 3 bimodality results from the σ28-FlgM developmental checkpoint. IMPORTANCE Many bacterial use flagella to swim in liquids and swarm over surface. In Salmonella enterica, over 50 genes are required to assemble flagella. The expression of these genes is tightly regulated. Previous studies have found that flagellar gene expression is bimodal in S. enterica, which means that only a fraction of cells express flagellar genes and are motile. In the present study, we found that two separate mechanisms induce this bimodal response. One mechanism, which was previously identified, tunes the fraction of motile cells in response to nutrients. The other results from a developmental checkpoint that couples flagellar gene expression to flagellar assembly. Collectively, these results further our understanding of how flagellar gene expression is regulated in S. enterica.

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