scholarly journals A Cyclic AMP Receptor Protein-Regulated Cell-Cell Communication System Mediates Expression of a FecA Homologue in Stenotrophomonas maltophilia

2007 ◽  
Vol 73 (15) ◽  
pp. 5034-5040 ◽  
Author(s):  
Tzu-Pi Huang ◽  
Amy C. Lee Wong
Keyword(s):  
Cyclic Amp ◽  
Communication System ◽  
Stenotrophomonas Maltophilia ◽  
Environmental Changes ◽  
Cell Communication ◽  
Transcript Level ◽  
Ferric Citrate ◽  
Receptor Protein ◽  
Wild Type ◽  
Cell Cell

ABSTRACT Stenotrophomonas maltophilia WR-C possesses an rpf/diffusible signal factor (DSF) cell-cell communication system. It produces cis-Δ2-11-methyl-dodecenoic acid, a DSF, and seven structural derivatives, which require rpfF and rpfB for synthesis. Acquisition of iron from the environment is important for bacterial growth as well as the expression of virulence genes. We identified a gene homologous to fecA, which encodes a ferric citrate receptor that transports exogenous siderophore ferric citrate from the environment into the bacterial periplasm. Western blot analysis with anti-FecA-His6 antibody showed that the FecA homologue was induced in the iron-depleted medium supplemented with a low concentration of ferric citrate. Deletion of rpfF or rpfB resulted in reduced FecA expression compared to the wild type. Synthetic DSF restored FecA expression by the ΔrpfF mutant to the wild-type level. Reverse transcription-PCR showed that the fecA transcript was decreased in the ΔrpfF mutant compared to the wild type. These data suggest that DSF affected the level of fecA mRNA. Transposon inactivation of crp, which encodes cyclic AMP (cAMP) receptor protein (CRP) resulted in reduced FecA expression and rpfF transcript level. Putative CRP binding sites were located upstream of the rpfF promoter, indicating that the effect of CRP on FecA is through the rpf/DSF pathway and by directly controlling rpfF. We propose that CRP may serve as a checkpoint for iron uptake, protease activity, and hemolysis in response to environmental changes such as changes in concentrations of glucose, cAMP, iron, or DSF.

scholarly journals A cell-cell communication system regulates protease production during sporulation in bacteria of the Bacillus cereus group

2011 ◽  
Vol 82 (3) ◽  
pp. 619-633 ◽  
Author(s):  
Stéphane Perchat ◽  
Thomas Dubois ◽  
Samira Zouhir ◽  
Myriam Gominet ◽  
Sandrine Poncet ◽  
...  
Keyword(s):  
Bacillus Cereus ◽  
Communication System ◽  
Cell Communication ◽  
Protease Production ◽  
Bacillus Cereus Group ◽  
A Cell ◽  
Cell Cell

scholarly journals Mutations in the cyclic AMP binding site of the cyclic AMP receptor protein of Escherichia coli

1988 ◽  
Vol 253 (3) ◽  
pp. 801-807 ◽  
Author(s):  
A M Gronenborn ◽  
R Sandulache ◽  
S Gärtner ◽  
G M Clore
Keyword(s):  
Escherichia Coli ◽  
Cyclic Amp ◽  
Binding Site ◽  
Cyclic Nucleotides ◽  
Binding Pocket ◽  
Receptor Protein ◽  
Directed Mutagenesis ◽  
Wild Type ◽  
Cyclic Amp Receptor Protein ◽  
Better Than

Mutants in the cyclic AMP binding site of the cyclic AMP receptor protein (CRP) of Escherichia coli have been constructed by oligonucleotide-directed mutagenesis. They have been phenotypically characterized and their ability to enhance the expression of catabolite-repressible operons has been tested. In addition, the binding of cyclic nucleotides to the mutants has been investigated. It is shown that the six mutants made fall into one of three classes: (i) those that bind cyclic AMP better than the wild type protein (Ser-62→Ala) and result in greater transcription enhancement; (ii) those that bind cyclic AMP similarly to wild type (Ser-83→Ala, Ser-83→Lys, Thr-127→Ala, Ser-129→Ala); and (iii) those that do not bind cyclic AMP at all (Arg-82→Leu). Implications of these findings with respect to present models of the cyclic nucleotide binding pocket of CRP are discussed.

scholarly journals Cyclic AMP (cAMP) and cAMP Receptor Protein Influence both Synthesis and Uptake of Extracellular Autoinducer 2 in Escherichia coli

2005 ◽  
Vol 187 (6) ◽  
pp. 2066-2076 ◽  
Author(s):  
Liang Wang ◽  
Yoshifumi Hashimoto ◽  
Chen-Yu Tsao ◽  
James J. Valdes ◽  
William E. Bentley
Keyword(s):  
Escherichia Coli ◽  
Cyclic Amp ◽  
Carbon Sources ◽  
Cell Communication ◽  
Receptor Protein ◽  
Upstream Region ◽  
E Coli ◽  
Autoinducer 2 ◽  
Serovar Typhimurium ◽  
Camp Receptor

ABSTRACT Bacterial autoinducer 2 (AI-2) is proposed to be an interspecies mediator of cell-cell communication that enables cells to operate at the multicellular level. Many environmental stimuli have been shown to affect the extracellular AI-2 levels, carbon sources being among the most important. In this report, we show that both AI-2 synthesis and uptake in Escherichia coli are subject to catabolite repression through the cyclic AMP (cAMP)-CRP complex, which directly stimulates transcription of the lsr (for “luxS regulated”) operon and indirectly represses luxS expression. Specifically, cAMP-CRP is shown to bind to a CRP binding site located in the upstream region of the lsr promoter and works with the LsrR repressor to regulate AI-2 uptake. The functions of the lsr operon and its regulators, LsrR and LsrK, previously reported in Salmonella enterica serovar Typhimurium, are confirmed here for E. coli. The elucidation of cAMP-CRP involvement in E. coli autoinduction impacts many areas, including the growth of E. coli in fermentation processes.

scholarly journals A Critical-like Collective State Leads to Long-range Cell Communication in Dictyostelium discoideum Aggregation

2016 ◽  
Author(s):  
Giovanna De Palo ◽  
Darvin Yi ◽  
Robert G. Endres
Keyword(s):  
Single Cell ◽  
Dictyostelium Discoideum ◽  
Long Range ◽  
Early Development ◽  
Cell Communication ◽  
Multiscale Model ◽  
Wild Type ◽  
Social Amoeba ◽  
Range Cell ◽  
Cell Cell

AbstractThe transition from single-cell to multicellular behavior is important in early development but rarely studied. The starvation-induced aggregation of the social amoeba Dictyostelium discoideum into a multicellular slug is known to result from single-cell chemotaxis towards emitted pulses of cyclic adenosine monophosphate (cAMP). However, how exactly do transient short-range chemical gradients lead to coherent collective movement at a macroscopic scale? Here, we developed a multiscale model verified by quantitative microscopy to describe wide-ranging behaviors from chemotaxis and excitability of individual cells to aggregation of thousands of cells. To better understand the mechanism of long-range cell-cell communication and hence aggregation, we analyzed cell-cell correlations, showing evidence of self-organization at the onset of aggregation (as opposed to following a leader cell). Surprisingly, cell collectives, despite their finite size, show features of criticality known from phase transitions in physical systems. By comparing wild-type and mutant cells with impaired aggregation, we found the longest cellcell communication distance in wild-type cells, suggesting that criticality provides an adaptive advantage and optimally sized aggregates for the dispersal of spores.Author SummaryCells are often coupled to each other in cell collectives, such as aggregates during early development, tissues in the developed organism, and tumors in disease. How do cells communicate over macroscopic distances much larger than the typical cell-cell distance to decide how they should behave? Here, we developed a multiscale model of social amoeba, spanning behavior from individuals to thousands of cells. We show that local cell-cell coupling via secreted chemicals may be tuned to a critical value, resulting in emergent long-range communication and heightened sensitivity. Hence, these aggregates are remarkably similar to bacterial biofilms and neuronal networks, all communicating in a pulse-like fashion. Similar organizing principles may also aid our understanding of the remarkable robustness in cancer development.

The dependence of Escherichia coli asparaginase II formation on cyclic AMP and cyclic AMP receptor protein

1978 ◽  
Vol 24 (5) ◽  
pp. 629-631 ◽  
Author(s):  
La Verne Russell ◽  
Hiroshi Yamazaki
Keyword(s):  
Escherichia Coli ◽  
Cyclic Amp ◽  
Type Strain ◽  
Wild Type Strain ◽  
Anaerobic Growth ◽  
Receptor Protein ◽  
Wild Type ◽  
Cyclic Amp Receptor Protein ◽  
E Coli ◽  
Cyclic Amp Synthesis

The amount of asparaginase II in an Escherichia coli wild-type strain (cya+, crp+) markedly increased upon a shift from aerobic to anaerobic growth. However, no such increase occurred in a mutant (cya) lacking cyclic AMP synthesis unless supplemented with exogenous cyclic AMP. Since a mutant (crp) deficient in cyclic AMP receptor protein also did not support the anaerobic formation of this enzyme, it is concluded that the formation of E. coli asparaginase II depends on both cyclic AMP and cyclic AMP receptor protein.

scholarly journals Cooperation between oncogenic Ras and wild-type p53 stimulates STAT non-cell autonomously to promote tumor radioresistance

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Yong-Li Dong ◽  
Gangadhara P. Vadla ◽  
Jin-Yu (Jim) Lu ◽  
Vakil Ahmad ◽  
Thomas J. Klein ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Cellular Response ◽  
Cell Communication ◽  
Genotoxic Stress ◽  
Tumor Resistance ◽  
Wild Type ◽  
Therapy Outcomes ◽  
Oncogenic Ras ◽  
Tumor Tissues ◽  
Cell Cell

AbstractOncogenic RAS mutations are associated with tumor resistance to radiation therapy. Cell-cell interactions in the tumor microenvironment (TME) profoundly influence therapy outcomes. However, the nature of these interactions and their role in Ras tumor radioresistance remain unclear. Here we use Drosophila oncogenic Ras tissues and human Ras cancer cell radiation models to address these questions. We discover that cellular response to genotoxic stress cooperates with oncogenic Ras to activate JAK/STAT non-cell autonomously in the TME. Specifically, p53 is heterogeneously activated in Ras tumor tissues in response to irradiation. This mosaicism allows high p53-expressing Ras clones to stimulate JAK/STAT cytokines, which activate JAK/STAT in the nearby low p53-expressing surviving Ras clones, leading to robust tumor re-establishment. Blocking any part of this cell-cell communication loop re-sensitizes Ras tumor cells to irradiation. These findings suggest that coupling STAT inhibitors to radiotherapy might improve clinical outcomes for Ras cancer patients.

scholarly journals The Cyclic AMP Receptor Protein Is Dependent on GcvA for Regulation of the gcv Operon

1999 ◽  
Vol 181 (6) ◽  
pp. 1912-1919 ◽  
Author(s):  
Laura D. Wonderling ◽  
George V. Stauffer
Keyword(s):  
Cyclic Amp ◽  
Transcription Initiation ◽  
Mutational Analysis ◽  
Initiation Site ◽  
Receptor Protein ◽  
Single Mutation ◽  
Wild Type ◽  
Double Deletion ◽  
Footprint Analysis ◽  
Camp Receptor

ABSTRACT The Escherichia coli gcv operon is transcriptionally regulated by the GcvA, GcvR, Lrp, and PurR proteins. In this study, the cyclic AMP (cAMP) receptor protein (CRP) is shown to be involved in positive regulation of the gcv operon. A crpdeletion reduced expression of a gcvT-lacZ fusion almost fourfold in glucose minimal (GM) medium. The phenotype was complemented by both the wild-type crp gene and four crpalleles that encode proteins with amino acid substitutions in known activating regions of CRP. A cyaA deletion also resulted in a fourfold decrease in gcvT-lacZ expression, and wild-type expression was restored by the addition of cAMP to the growth medium. AcyaA crp double deletion resulted in levels ofgcvT-lacZ expression identical to those observed with either single mutation, showing that CRP and cAMP regulate through the same mechanism. Growth in GM medium plus cAMP or glycerol minimal medium did not result in a significant increase ingcvT-lacZ expression. Thus, the level of cAMP present in GM medium appears to be sufficient for regulation by CRP. DNase I footprint analysis showed that CRP binds and protects two sites centered at bp −313 (site 1) and bp −140 (site 2) relative to the transcription initiation site, but a mutational analysis demonstrated that only site 1 is required for CRP-mediated regulation ofgcvT-lacZ expression. Expression of thegcvT-lacZ fusion in a crp gcvA double mutant suggested that CRP’s role is dependent on the GcvA protein.

scholarly journals Phototaxis and Impaired Motility in Adenylyl Cyclase and Cyclase Receptor Protein Mutants of Synechocystis sp. Strain PCC 6803

2006 ◽  
Vol 188 (20) ◽  
pp. 7306-7310 ◽  
Author(s):  
Devaki Bhaya ◽  
Kenlee Nakasugi ◽  
Fariba Fazeli ◽  
Matthew S. Burriesci
Keyword(s):  
Cyclic Amp ◽  
Adenylyl Cyclase ◽  
Receptor Protein ◽  
Wild Type ◽  
Catabolite Activator Protein ◽  
Activator Protein ◽  
Protein Mutants ◽  
Synechocystis Sp ◽  
Pcc 6803

ABSTRACT We have carefully characterized and reexamined the motility and phototactic responses of Synechocystis sp. adenylyl cyclase (Cya1) and catabolite activator protein (SYCRP1) mutants to different light regimens, glucose, 3-(3,4-dichlorophenyl)-1,1-dimethylurea, and cyclic AMP. We find that contrary to earlier reports, cya1 and sycrp1 mutants are motile and phototactic but are impaired in one particular phase of phototaxis in comparison with wild-type Synechocystis sp.

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