Screening of promoter-specific transcription factors: multiple regulators for the sdiA gene involved in cell division control and quorum sensing

Microbiology ◽  
2013 ◽  
Vol 159 (Pt_12) ◽  
pp. 2501-2512 ◽  
Author(s):  
Kaori Shimada ◽  
Hiroshi Ogasawara ◽  
Kayoko Yamada ◽  
Miki Shimura ◽  
Ayako Kori ◽  
...  
2014 ◽  
Vol 19 (5) ◽  
pp. 405-418 ◽  
Author(s):  
Tomohiro Shimada ◽  
Kaori Shimada ◽  
Makoto Matsui ◽  
Yuichi Kitai ◽  
Jun Igarashi ◽  
...  

Author(s):  
B M Kállai ◽  
H Kourová ◽  
J Chumová ◽  
C Papdi ◽  
L Trögelová ◽  
...  

Abstract γ-Tubulin is associated with microtubule nucleation, but evidence is accumulating in eukaryotes that it functions also in nuclear processes and in cell division control that are independent of its canonical role. We found that in Arabidopsis thaliana γ-tubulin interacts specifically with E2FA, E2FB, and E2FC transcription factors both in vitro and in vivo. The interaction of γ-tubulin with the E2Fs is not reduced in the presence of the dimerization partners (DPs) and, in agreement, we found that γ-tubulin interaction with E2Fs does not require the dimerization domain. γ-Tubulin associates with the promoters of E2F-regulated cell cycle genes in an E2F dependent manner, likely in complex with the E2F/DP heterodimer. The upregulation of E2F targets; PCNA, ORC2, CDKB1;1 and CCS52A under γtubulin silencing suggests a repressive function for γ-tubulin at G1/S, G2/M and endocycle, which is consistent with an excess of cell division in some cells and enhanced endoreduplication in others in the shoot and young leaves of γ-tubulin RNAi plants. Altogether, our data show ternary interaction of γ-tubulin with E2F/DP heterodimer and suggest a repressive role for γ-tubulin with E2Fs in controlling mitotic activity and endoreduplication during plant development.


2017 ◽  
Vol 95 (3) ◽  
Author(s):  
Jacopo Grilli ◽  
Matteo Osella ◽  
Andrew S. Kennard ◽  
Marco Cosentino Lagomarsino

1990 ◽  
Vol 68 (12) ◽  
pp. 1297-1330 ◽  
Author(s):  
Steven L. Pelech ◽  
Jasbinder S. Sanghera ◽  
Maleki Daya-Makin

Eukaryotic cell cycle progression during meiosis and mitosis is extensively regulated by reversible protein phosphorylation. Many cell surface receptors for mitogens are ligand-stimulated protein-tyrosine kinases that control the activation of a network of cytoplasmic and nuclear protein-serine(threonine) kinases. Over 30 plasma membrane associated protein-tyrosine kinases are encoded by proto-oncogenes, i.e., genes that have the potential to facilitate cancer when disregulated. Proteins such as ribosomal protein S6, microtubule-associated protein-2, myelin basic protein, and casein have been used to detect intracellular protein-serine(threonine) kinases that are activated further downstream in growth factor signalling transduction cascades. Genetic analysis of yeast cell division control (cdc) mutants has revealed another 20 or so protein-serine(threonine) kinases. One of these, specified by the cdc-2 gene in Schizosaccharomyces pombe, has homologs that are stimulated during M phase in maturing sea star and frog oocytes and mammalian somatic cells. Furthermore, during meiotic maturation in these echinoderm and amphibian oocytes, this is followed by activation of many of the same protein-serine(threonine) kinases that are stimulated when quiescent mammalian somatic cells are prompted with mitogens to traverse from G0 to G1 phase. These findings imply that a similar protein kinase cascade may oversee progression at multiple points in the cell cycle.Key words: protein kinases, mitosis, meiosis, oncogenes, cell division control.


2019 ◽  
Vol 201 (9) ◽  
Author(s):  
Hui Zhou ◽  
Meizhen Wang ◽  
Nicole E. Smalley ◽  
Maxim Kostylev ◽  
Amy L. Schaefer ◽  
...  

ABSTRACT Pseudomonas aeruginosa uses quorum sensing (QS) to regulate the production of a battery of secreted products. At least some of these products are shared among the population and serve as public goods. When P. aeruginosa is grown on casein as the sole carbon and energy source, the QS-induced extracellular protease elastase is required for growth. We isolated a P. aeruginosa variant, which showed increased production of QS-induced factors after repeated transfers in casein broth. This variant, P. aeruginosa QS*, had a mutation in the glutathione synthesis gene gshA. We describe several experiments that show a gshA coding variant and glutathione affect the QS response. The P. aeruginosa QS transcription factor LasR has a redox-sensitive cysteine (C79). We report that GshA variant cells with a LasR C79S substitution show a similar QS response to that of wild-type P. aeruginosa. Surprisingly, it is not LasR but the QS transcription factor RhlR that is more active in bacteria containing the variant gshA. Our results demonstrate that QS integrates information about cell density and the cellular redox state via glutathione levels. IMPORTANCE Pseudomonas aeruginosa and other bacteria coordinate group behaviors using a chemical communication system called quorum sensing (QS). The QS system of P. aeruginosa is complex, with several regulators and signals. We show that decreased levels of glutathione lead to increased gene activation in P. aeruginosa, which did not occur in a strain carrying the redox-insensitive variant of a transcription factor. The ability of P. aeruginosa QS transcription factors to integrate information about cell density and cellular redox state shows these transcription factors can fine-tune levels of the gene products they control in response to at least two types of signals or cues.


2020 ◽  
Vol 202 (14) ◽  
Author(s):  
Ryan R. Chaparian ◽  
Alyssa S. Ball ◽  
Julia C. van Kessel

ABSTRACT In vibrios, quorum sensing controls hundreds of genes that are required for cell density-specific behaviors including bioluminescence, biofilm formation, competence, secretion, and swarming motility. The central transcription factor in the quorum-sensing pathway is LuxR/HapR, which directly regulates ∼100 genes in the >400-gene regulon of Vibrio harveyi. Among these directly controlled genes are 15 transcription factors, which we predicted would comprise the second tier in the hierarchy of the LuxR regulon. We confirmed that LuxR binds to the promoters of these genes in vitro and quantified the extent of LuxR activation or repression of transcript levels. Transcriptome sequencing (RNA-seq) indicates that most of these transcriptional regulators control only a few genes, with the exception of MetJ, which is a global regulator. The genes regulated by these transcription factors are predicted to be involved in methionine and thiamine biosynthesis, membrane stability, RNA processing, c-di-GMP degradation, sugar transport, and other cellular processes. These data support a hierarchical model in which LuxR directly regulates 15 transcription factors that drive the second level of the gene expression cascade to influence cell density-dependent metabolic states and behaviors in V. harveyi. IMPORTANCE Quorum sensing is important for survival of bacteria in nature and influences the actions of bacterial groups. In the relatively few studied examples of quorum-sensing-controlled genes, these genes are associated with competition or cooperation in complex microbial communities and/or virulence in a host. However, quorum sensing in vibrios controls the expression of hundreds of genes, and their functions are mostly unknown or uncharacterized. In this study, we identify the regulators of the second tier of gene expression in the quorum-sensing system of the aquaculture pathogen Vibrio harveyi. Our identification of regulatory networks and metabolic pathways controlled by quorum sensing can be extended and compared to other Vibrio species to understand the physiology, ecology, and pathogenesis of these organisms.


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