scholarly journals The Cpx two-component signal transduction pathway is activated in Escherichia coli mutant strains lacking phosphatidylethanolamine.

1997 ◽  
Vol 179 (4) ◽  
pp. 1029-1034 ◽  
Author(s):  
E Mileykovskaya ◽  
W Dowhan
Keyword(s):  
Escherichia Coli ◽  
Signal Transduction ◽  
Signal Transduction Pathway ◽  
Transduction Pathway ◽  
Coli Mutant ◽  
Two Component ◽  
Mutant Strains ◽  
Two Component Signal Transduction

scholarly journals P Pilus Assembly Motif Necessary for Activation of the CpxRA Pathway by PapE in Escherichia coli

2004 ◽  
Vol 186 (13) ◽  
pp. 4326-4337 ◽  
Author(s):  
Yvonne M. Lee ◽  
Patricia A. DiGiuseppe ◽  
Thomas J. Silhavy ◽  
Scott J. Hultgren
Keyword(s):  
Escherichia Coli ◽  
Signal Transduction ◽  
Signal Transduction Pathway ◽  
The Self ◽  
Carboxyl Terminus ◽  
Transduction Pathway ◽  
Two Component ◽  
Pilus Biogenesis ◽  
Two Component Signal Transduction ◽  
Self Association

ABSTRACT P pilus biogenesis occurs via the highly conserved chaperone-usher pathway, and assembly is monitored by the CpxRA two-component signal transduction pathway. Structural pilus subunits consist of an N-terminal extension followed by an incomplete immunoglobulin-like fold that is missing a C-terminal seventh beta strand. In the pilus fiber, the immunoglobulin-like fold of each pilin is completed by the N-terminal extension of its neighbor. Subunits that do not get incorporated into the pilus fiber are driven “OFF-pathway.” In this study, we found that PapE was the only OFF-pathway nonadhesin P pilus subunit capable of activating Cpx. Manipulation of the PapE structure by removing, relocating within the protein, or swapping its N-terminal extension with that of other subunits altered the protein's self-associative and Cpx-activating properties. The self-association properties of the new subunits were dictated by the specific N-terminal extension provided and were consistent with the order of the subunits in the pilus fiber. However, these aggregation properties did not directly correlate with Cpx induction. Cpx activation instead correlated with the presence or absence of an N-terminal extension in the PapE pilin structure. Removal of the N-terminal extension of PapE was sufficient to abolish Cpx activation. Replacement of an N-terminal extension at either the amino or carboxyl terminus restored Cpx induction. Thus, the data presented in this study argue that PapE has features inherent in its structure or during its folding that act as specific inducers of Cpx signal transduction.

scholarly journals Dissecting the VanRS Signal Transduction Pathway with Specific Inhibitors

1999 ◽  
Vol 181 (2) ◽  
pp. 627-631 ◽  
Author(s):  
Andrew T. Ulijasz ◽  
Bernard Weisblum
Keyword(s):  
Signal Transduction ◽  
Pseudomonas Aeruginosa ◽  
Transcriptional Activation ◽  
Signal Transduction Pathway ◽  
Phosphoryl Transfer ◽  
Transduction Pathway ◽  
Two Component ◽  
Two Component Signal Transduction ◽  
Specific Inhibitors

ABSTRACT The VanRS two-component signal transduction pathway fromEnterococcus faecium was reconstituted in vitro from partially purified components and shown to be inhibited by the halophenyl isothiazolone LY-266,400, inhibitor A, a compound shown previously to reduce expression of the AlgR1-AlgR2 two-component signal transduction pathway in Pseudomonas aeruginosa (S. Roychoudhury, N. A. Zielinski, A. J. Ninfa, N. E. Allen, L. N. Jungheim, T. I. Nicas, and A. M. Chakrabarty, Proc. Natl. Acad. Sci. USA 90:965–969, 1993). Inhibitor A attenuates phosphoryl transfer from VanS∼P to VanR by its action on the ability of VanR to accept. We observed an apparent stimulatory effect of inhibitor A on VanS autophosphorylation which is attributable to the accumulation of VanS∼P as an intermediate unable to transfer Pi to the inhibited VanR. Thus, inhibitor A acts on the second of two sequential steps which lead to transcriptional activation of the VanHAXYZ gene cluster and the resultant expression of vancomycin resistance.

scholarly journals A Two-component Signal Transduction Pathway Regulates Manganese Homeostasis inSynechocystis6803, a Photosynthetic Organism

2002 ◽  
Vol 277 (32) ◽  
pp. 28981-28986 ◽  
Author(s):  
Teruo Ogawa ◽  
Ding Hui Bao ◽  
Hirokazu Katoh ◽  
Mari Shibata ◽  
Himadri B. Pakrasi ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Signal Transduction Pathway ◽  
Transduction Pathway ◽  
Two Component ◽  
Photosynthetic Organism ◽  
Two Component Signal Transduction

scholarly journals CpxP, a Stress-Combative Member of the Cpx Regulon

1998 ◽  
Vol 180 (4) ◽  
pp. 831-839 ◽  
Author(s):  
Paul N. Danese ◽  
Thomas J. Silhavy
Keyword(s):  
Escherichia Coli ◽  
Envelope Protein ◽  
Periplasmic Protein ◽  
Dependent Manner ◽  
Alkaline Ph ◽  
Signal Transduction System ◽  
Two Component ◽  
Mutant Strains ◽  
Alkaline Conditions ◽  
Two Component Signal Transduction

ABSTRACT The CpxA/R two-component signal transduction system ofEscherichia coli can combat a variety of extracytoplasmic protein-mediated toxicities. The Cpx system performs this function, in part, by increasing the synthesis of the periplasmic protease, DegP. However, other factors are also employed by the Cpx system for this stress-combative function. In an effort to identify these remaining factors, we screened a collection of random lacZ operon fusions for those fusions whose transcription is regulated by CpxA/R. Through this approach, we have identified a new locus,cpxP, whose transcription is stimulated by activation of the Cpx pathway. cpxP specifies a periplasmic protein that can combat the lethal phenotype associated with the synthesis of a toxic envelope protein. In addition, we show that cpxPtranscription is strongly induced by alkaline pH in a CpxA-dependent manner and that cpxP and cpx mutant strains display hypersensitivity to growth in alkaline conditions.

scholarly journals CheX in the Three-Phosphatase System of Bacterial Chemotaxis

2007 ◽  
Vol 189 (19) ◽  
pp. 7007-7013 ◽  
Author(s):  
Travis J. Muff ◽  
Richard M. Foster ◽  
Peter J. Y. Liu ◽  
George W. Ordal
Keyword(s):  
Escherichia Coli ◽  
Signal Transduction ◽  
Bacillus Subtilis ◽  
Mutant Strain ◽  
Response Regulator ◽  
Bacterial Chemotaxis ◽  
Signal Transduction System ◽  
Two Component ◽  
Two Component Signal Transduction ◽  
Phosphatase System

ABSTRACT Bacterial chemotaxis involves the regulation of motility by a modified two-component signal transduction system. In Escherichia coli, CheZ is the phosphatase of the response regulator CheY but many other bacteria, including Bacillus subtilis, use members of the CheC-FliY-CheX family for this purpose. While Bacillus subtilis has only CheC and FliY, many systems also have CheX. The effect of this three-phosphatase system on chemotaxis has not been studied previously. CheX was shown to be a stronger CheY-P phosphatase than either CheC or FliY. In Bacillus subtilis, a cheC mutant strain was nearly complemented by heterologous cheX expression. CheX was shown to overcome the ΔcheC adaptational defect but also generally lowered the counterclockwise flagellar rotational bias. The effect on rotational bias suggests that CheX reduced the overall levels of CheY-P in the cell and did not truly replicate the adaptational effects of CheC. Thus, CheX is not functionally redundant to CheC and, as outlined in the discussion, may be more analogous to CheZ.

scholarly journals A Novel Two-Component System, GluR-GluK, Involved in Glutamate Sensing and Uptake in Streptomyces coelicolor

2017 ◽  
Vol 199 (18) ◽  
Author(s):  
Lei Li ◽  
Weihong Jiang ◽  
Yinhua Lu
Keyword(s):  
Signal Transduction ◽  
Glutamate Uptake ◽  
Streptomyces Coelicolor ◽  
Signal Transduction Pathway ◽  
Antibiotic Biosynthesis ◽  
Transduction Pathway ◽  
Two Component System ◽  
Component System ◽  
Content Type ◽  
Two Component

ABSTRACT Two-component systems (TCSs), the predominant signal transduction pathways employed by bacteria, play important roles in physiological metabolism in Streptomyces. Here, a novel TCS, GluR-GluK (encoded by SCO5778-SCO5779), which is located divergently from the gluABCD operon encoding a glutamate uptake system, was identified as being involved in glutamate sensing and uptake as well as antibiotic biosynthesis in Streptomyces coelicolor. Under the condition of minimal medium (MM) supplemented with different concentrations of glutamate, deletion of the gluR-gluK operon (gluR-K) resulted in enhanced actinorhodin (ACT) but reduced undecylprodigiosin (RED) and yellow type I polyketide (yCPK) production, suggesting that GluR-GluK plays a differential role in antibiotic biosynthesis. Furthermore, we found that the response regulator GluR directly promotes the expression of gluABCD under the culture condition of MM with a high concentration of glutamate (75 mM). Using the biolayer interferometry assay, we demonstrated that glutamate acts as the direct signal of the histidine kinase GluK. It was therefore suggested that upon sensing high concentrations of glutamate, GluR-GluK would be activated and thereby facilitate glutamate uptake by increasing gluABCD expression. Finally, we demonstrated that the role of GluR-GluK in antibiotic biosynthesis is independent of its function in glutamate uptake. Considering the wide distribution of the glutamate-sensing (GluR-GluK) and uptake (GluABCD) module in actinobacteria, it could be concluded that the GluR-GluK signal transduction pathway involved in secondary metabolism and glutamate uptake should be highly conserved in this bacterial phylum. IMPORTANCE In this study, a novel two-component system (TCS), GluR-GluK, was identified to be involved in glutamate sensing and uptake as well as antibiotic biosynthesis in Streptomyces coelicolor. A possible GluR-GluK working model was proposed. Upon sensing high glutamate concentrations (such as 75 mM), activated GluR-GluK could regulate both glutamate uptake and antibiotic biosynthesis. However, under a culture condition of MM supplemented with low concentrations of glutamate (such as 10 mM), although GluR-GluK is activated, its activity is sufficient only for the regulation of antibiotic biosynthesis. To the best of our knowledge, this is the first report describing a TCS signal transduction pathway for glutamate sensing and uptake in actinobacteria.

scholarly journals A role for autophosphorylation revealed by activated alleles of FUS3, the yeast MAP kinase homolog.

1994 ◽  
Vol 5 (3) ◽  
pp. 297-312 ◽  
Author(s):  
J A Brill ◽  
E A Elion ◽  
G R Fink
Keyword(s):  
Escherichia Coli ◽  
Signal Transduction ◽  
Map Kinase ◽  
Signal Transduction Pathway ◽  
Transduction Pathway ◽  
Phosphorylated Form ◽  
Protein Map ◽  
Mitogen Activated Protein ◽  
Mating Signal

We have isolated dominant gain-of-function (gf) mutations in FUS3, a Saccharomyces cerevisiae mitogen-activated protein (MAP) kinase homolog, that constitutively activate the yeast mating signal transduction pathway and confer hypersensitivity to mating pheromone. Surprisingly, the phenotypes of dominant FUS3gf mutations require the two protein kinases, STE7 and STE11. FUS3gf kinases are hyperphosphorylated in yeast independently of STE7. Consistent with this, FUS3gf kinases expressed in Escherichia coli exhibit an increased ability to autophosphorylate on tyrosine in vivo. FUS3gf mutations suppress the signal transduction defect of a severely catalytically impaired allele of STE7. This finding suggests that the tyrosine-phosphorylated form of FUS3 is a better substrate for activation by STE7. Furthermore, these results imply that the degree of autophosphorylation of a MAP kinase determines its threshold of sensitivity to upstream signals.

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