Growth rate-dependent regulation of RNA polymerase synthesis in Escherichia coli

Ralling, Geoffrey; Bodrug, Sharon; Linn, Thomas

doi:10.1007/bf00331327

Cited by 35 publications

(22 citation statements)

References 53 publications

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“…These analyses can be done at a species-specific level by combining the flow-cytometric determination of relative DNA distributions with the precise detection of organisms using rRNA-based species-specific probes (47). An alternative approach consists of using cell cycle-related genes as indicators of population growth rates (24,25,32,37). The species-specific detection of a cell cycle-related gene and its concomitant quantification will, potentially, allow the determination of precise in situ growth rates of Alexandrium and other harmful algal bloom species in the future.…”

Section: Discussionmentioning

confidence: 99%

Identification and Characterization of Three Differentially Expressed Genes, Encoding S -Adenosylhomocysteine Hydrolase, Methionine Aminopeptidase, and a Histone-Like Protein, in the Toxic Dinoflagellate Alexandrium fundyense

Taroncher-Oldenburg

Anderson

2000

Appl Environ Microbiol

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Genes showing differential expression related to the early G 1 phase of the cell cycle during synchronized circadian growth of the toxic dinoflagellate Alexandrium fundyense were identified and characterized by differential display (DD). The determination in our previous work that toxin production in Alexandrium is relegated to a narrow time frame in early G 1 led to the hypothesis that transcriptionally up-or downregulated genes during this subphase of the cell cycle might be related to toxin biosynthesis. Three genes, encoding Sadenosylhomocysteine hydrolase (Sahh), methionine aminopeptidase (Map), and a histone-like protein (HAf), were isolated. Sahh was downregulated, while Map and HAf were upregulated, during the early G 1 phase of the cell cycle. Sahh and Map encoded amino acid sequences with about 90 and 70% similarity to those encoded by several eukaryotic and prokaryotic Sahh and Map genes, respectively. The partial Map sequence also contained three cobalt binding motifs characteristic of all Map genes. HAf encoded an amino acid sequence with 60% similarity to those of two histone-like proteins from the dinoflagellate Crypthecodinium cohnii Biecheler. This study documents the potential of applying DD to the identification of genes that are related to physiological processes or cell cycle events in phytoplankton under conditions where small sample volumes represent an experimental constraint. The identification of an additional 21 genes with various cell cycle-related DD patterns also provides evidence for the importance of pretranslational or transcriptional regulation in dinoflagellates, contrary to previous reports suggesting the possibility that translational mechanisms are the primary means of circadian regulation in this group of organisms.

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Section: Discussionmentioning

confidence: 99%

Identification and Characterization of Three Differentially Expressed Genes, Encoding S -Adenosylhomocysteine Hydrolase, Methionine Aminopeptidase, and a Histone-Like Protein, in the Toxic Dinoflagellate Alexandrium fundyense

Taroncher-Oldenburg

Anderson

2000

Appl Environ Microbiol

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“…The bacterial strains, plasmids, and bacteriophages used in this study are listed in Table 1. Monolysogens were formed in E. coli MG4, a recA derivative of E. coli MG1655 which also carries a ⌬(argF-lacIPOZYA)205 mutation (25). E. coli C600 was used for plaque purification and phage lysates (1).…”

Section: Methodsmentioning

confidence: 99%

Activation of the Pseudomonas aeruginosa lasI gene by LasR and the Pseudomonas autoinducer PAI: an autoinduction regulatory hierarchy

1995

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In Pseudomonas aeruginosa, the transcriptional activator LasR and the Pseudomonas autoinducer PAI, are necessary for efficient transcriptional activation of the lasB gene, encoding elastase (L. Passador, J. M. Cook, M. J. Gambello, L. Rust, and B. H. Iglewski, Science 260:1127-1130, 1993). The transcriptional start points of lasI in Escherichia coli and P. aeruginosa were determined by S1 nuclease mapping. In the presence of both LasR and PAI, the start site, T1, is located at position ؊25 relative to the ATG translational start codon. A minor transcriptional start, T2, is found at position ؊13 when lasI is transcribed in the absence of either LasR or PAI in P. aeruginosa and E. coli, respectively. To begin to closely examine the regulation of lasI, whose product is involved in the synthesis of PAI, a lasI-lacZ fusion on a lambda phage was constructed to form monolysogens of E. coli MG4. Lysogens supplied only with either lasI or lasR via multicopy plasmids demonstrated no significant increase in ␤-galactosidase expression compared with control levels. Lysogens in which both lasR and lasI were supplied in multicopy exhibited a 62-fold increase in expression, and a lysogen in which lasR was supplied in trans and which was grown in the presence of exogenous PAI exhibited a 60-fold increase. Thus, LasR and PAI are necessary for the full expression of lasI in E. coli. The interchangeability of the P. aeruginosa and Vibrio fischeri homologs LasR and LuxR and their respective autoinducers, PAI and VAI, as activators of lasI-lacZ was examined. Only the combination of LasR and PAI significantly increased the expression of lasI. The comparison of lasI-lacZ and lasB-lacZ expression in lysogens grown in the presence of lasR and PAI revealed that half-maximal expression of lasI required 0.1 nM PAI, in contrast to the 1.0 nM PAI necessary for lasB half-maximal expression. These results suggest an autoinduction regulatory hierarchy in which LasR and low PAI concentrations primarily activate lasI expression in a regulatory loop. With the accumulation of PAI, secondary activation of virulence product genes such as lasB occurs.Multiple homologous regulatory systems which entail the interaction of a diffusible effector molecule, termed an autoinducer, with a transcriptional activating protein to induce expression of different target genes have been described for gram-negative bacteria. The transcriptional activators and autoinducers in these processes are closely related, and the protein activators display significant peptide sequence homology, particularly in their putative DNA-binding domains. Vibrio fischeri (6,7,20), Agrobacterium tumefaciens (24, 33), Erwinia carotovora (2, 17), and Pseudomonas aeruginosa (22) are among the prokaryotic organisms which utilize this type of regulation, to control bioluminescence (V. fischeri), conjugation (A. tumefaciens), and virulence factor (E. carotovora and P. aeruginosa) regulation.P. aeruginosa, a gram-negative opportunistic human pathogen, uses the transcriptional activator protein, La...

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“…coli strains. MG2 is a A(argF-hc)U169 derivative of MG16.5.5, MG4 is a recA.56 derivative of MG2 (Ralling et al, 1985). C600 was described by Appleyard (1954 (2730) HindIII (1339) DdeI (2672) HindIII (1339) NarI (2730) HindIII (1339) DdeI (2672) SwaI (2279) SwaI (2279) EcoRI (2444) EcoRI (2444) HindIII (1339) HindIII (1339) HindIII (1339) EcoRI (2444) EcoRI (2444) SwaI (2279) SwaI (2279) HindIII (1339) AluI (2623) AluI (2623) AluI (2623) Ah1 (2623) DdeI (2672) NarI (2730) DdeI (2672) NarI (2730) NarI (2730) DdeI (2672) NarI (2730 Post et al (1979).…”

Section: Methodsmentioning

confidence: 99%

Transcription-frequency-dependent modulation of an attenuator in a ribosomal protein-RNA polymerase operon requires an upstream site

1997

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Although the attenuator located between the ribosomal protein and RNA polymerase gene domains of the Escherichia coli rplKAILrpoBC operon has a maximum termination efficiency of 8O%, the level of termination is diminished with decreasing transcription frequency. In this report, the use of transcriptional fusions t o further investigate the mechanism of transcriptionfrequency-dependent regulation is described. The termination efficiency of two other weak terminators was assayed over a wide range of transcription frequencies programmed by different strength promoters. The results indicated that a decrease in termination efficiency with decreasing transcription frequency is not an inherent property of weak terminators. Deletion of the 165 bp segment located 439-274 bp upstream of the attenuator abrogated the difference in termination efficiency normally seen between high and low levels of transcription. This suggests that a cis-acting site located in this upstream region is necessary for transcription-frequency-dependent modulation of the attenuator's function. However, this site apparently works only in combination with the attenuator, since it did not cause transcriptionfrequency-dependent modulation when placed upstream of two other weak terminators. Analysis of the readthrough frequencies of single or tandem copies of the attenuator indicated that the transcription complexes which pass through the attenuator have not been converted t o termination-resistant complexes in a manner analogous t o the N-mediated antitermination system of lambda. Finally, an examination of termination efficiency in three nusA mutants suggested that although NusA increases readthrough at the attenuator it is not directly involved in transcription-frequencyldependent modulation.

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Growth rate-dependent regulation of RNA polymerase synthesis in Escherichia coli

Cited by 35 publications

References 53 publications

Identification and Characterization of Three Differentially Expressed Genes, Encoding S -Adenosylhomocysteine Hydrolase, Methionine Aminopeptidase, and a Histone-Like Protein, in the Toxic Dinoflagellate Alexandrium fundyense

Identification and Characterization of Three Differentially Expressed Genes, Encoding S -Adenosylhomocysteine Hydrolase, Methionine Aminopeptidase, and a Histone-Like Protein, in the Toxic Dinoflagellate Alexandrium fundyense

Activation of the Pseudomonas aeruginosa lasI gene by LasR and the Pseudomonas autoinducer PAI: an autoinduction regulatory hierarchy

Transcription-frequency-dependent modulation of an attenuator in a ribosomal protein-RNA polymerase operon requires an upstream site

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