scholarly journals Hybrid sensor kinase PA1611 inPseudomonas aeruginosaregulates transitions between acute and chronic infection through direct interaction with RetS

2013 ◽  
Vol 88 (4) ◽  
pp. 784-797 ◽  
Author(s):  
Weina Kong ◽  
Lin Chen ◽  
Jieqiong Zhao ◽  
Tuo Shen ◽  
Michael G. Surette ◽  
...  
Keyword(s):  
Chronic Infection ◽  
Direct Interaction ◽  
Sensor Kinase

scholarly journals Direct interaction between sensor kinase proteins mediates acute and chronic disease phenotypes in a bacterial pathogen

2009 ◽  
Vol 23 (2) ◽  
pp. 249-259 ◽  
Author(s):  
A. L. Goodman ◽  
M. Merighi ◽  
M. Hyodo ◽  
I. Ventre ◽  
A. Filloux ◽  
...  
Keyword(s):  
Chronic Disease ◽  
Bacterial Pathogen ◽  
Direct Interaction ◽  
Sensor Kinase ◽  
Disease Phenotypes

scholarly journals Site-Specific Mutation of the Sensor Kinase GraS in Staphylococcus aureus Alters the Adaptive Response to Distinct Cationic Antimicrobial Peptides

2014 ◽  
Vol 82 (12) ◽  
pp. 5336-5345 ◽  
Author(s):  
Ambrose L. Cheung ◽  
Arnold S. Bayer ◽  
Michael R. Yeaman ◽  
Yan Q. Xiong ◽  
Alan J. Waring ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Peptides ◽  
Target Genes ◽  
Regulatory System ◽  
Direct Interaction ◽  
Sensor Kinase ◽  
Target Tissue ◽  
Cationic Antimicrobial Peptides ◽  
Content Type

ABSTRACTTheStaphylococcus aureustwo-component regulatory system, GraRS, is involved in resistance to killing by distinct host defense cationic antimicrobial peptides (HD-CAPs). It is believed to regulate downstream target genes such asmprFanddltABCDto modify theS. aureussurface charge. However, the detailed mechanism(s) by which the histidine kinase, GraS, senses specific HD-CAPs is not well defined. Here, we studied a well-characterized clinical methicillin-resistantS. aureus(MRSA) strain (MW2), its isogenicgraSdeletion mutant (ΔgraSstrain), a nonameric extracellular loop mutant (ΔEL strain), and four residue-specific ΔEL mutants (D37A, P39A, P39S, and D35G D37G D41G strains). The ΔgraSand ΔEL strains were unable to inducemprFanddltAexpression and, in turn, demonstrated significantly increased susceptibilities to daptomycin, polymyxin B, and two prototypical HD-CAPs (hNP-1 and RP-1). Further, P39A, P39S, and D35G-D37G-D41G ΔEL mutations correlated with moderate increases in HD-CAP susceptibility. Reductions ofmprFanddltAinduction by PMB were also found in the ΔEL mutants, suggesting these residues are pivotal to appropriate activation of the GraS sensor kinase. Importantly, a synthetic exogenous soluble EL mimic of GraS protected the parental MW2 strain against hNP-1- and RP-1-mediated killing, suggesting a direct interaction of the EL with HD-CAPs in GraS activation.In vivo, the ΔgraSand ΔEL strains displayed dramatic reductions in achieved target tissue MRSA counts in an endocarditis model. Taken together, our results provide new insights into potential roles of GraS inS. aureussensing of HD-CAPs to induce adaptive survival responses to these molecules.

Nutrient-regulated gene expression in eukaryotes

2006 ◽  
Vol 73 ◽  
pp. 85-96 ◽  
Author(s):  
Richard J. Reece ◽  
Laila Beynon ◽  
Stacey Holden ◽  
Amanda D. Hughes ◽  
Karine Rébora ◽  
...  
Keyword(s):  
Gene Expression ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Transcriptional Control ◽  
Direct Interaction ◽  
Signalling Pathways ◽  
A Cell ◽  
One Step ◽  
Higher Eukaryotes ◽  
Regulated Gene Expression

The recognition of changes in environmental conditions, and the ability to adapt to these changes, is essential for the viability of cells. There are numerous well characterized systems by which the presence or absence of an individual metabolite may be recognized by a cell. However, the recognition of a metabolite is just one step in a process that often results in changes in the expression of whole sets of genes required to respond to that metabolite. In higher eukaryotes, the signalling pathway between metabolite recognition and transcriptional control can be complex. Recent evidence from the relatively simple eukaryote yeast suggests that complex signalling pathways may be circumvented through the direct interaction between individual metabolites and regulators of RNA polymerase II-mediated transcription. Biochemical and structural analyses are beginning to unravel these elegant genetic control elements.

PRE CANCER LESION H. pylori CHRONIC INFECTION

2000 ◽  
Vol 15 (12) ◽  
pp. H29-H29
Author(s):  
Vera D. Yoewono ◽  
E. Krinuhoni ◽  
W Marwoto ◽  
S.O. Sri Widodo
Keyword(s):  
Chronic Infection ◽  
H Pylori ◽  
Cancer Lesion

Demonstration of a direct interaction between a colonic divalent cation receptor and the basolateral Na−H exchanger

2001 ◽  
Vol 120 (5) ◽  
pp. A529-A530
Author(s):  
P GEIBEL ◽  
M OREILLY ◽  
H VIEWEGER ◽  
K SIEBERT ◽  
N OBREIN ◽  
...  
Keyword(s):  
Divalent Cation ◽  
Direct Interaction ◽  
Cation Receptor

Detection of both Type 1 and Type 2 Plasminogen Activator Inhibitors in Human Monocytes

1990 ◽  
Vol 63 (01) ◽  
pp. 067-071 ◽  
Author(s):  
Joan C Castellote ◽  
Enric Grau ◽  
Maria A Linde ◽  
Nuria Pujol-Moix ◽  
Miquel LI Rutllant
Keyword(s):  
Molecular Mass ◽  
Plasminogen Activator ◽  
Human Peripheral Blood ◽  
Direct Interaction ◽  
Apparent Molecular Weight ◽  
Fibrinolytic System ◽  
Human Monocytes ◽  
Blood Monocytes ◽  
Single Chain ◽  
Sds Page

SummaryIncreasing evidence suggests the involvement of leukocytes in the fibrinolytic system. Monocytes secrete pro-urokinase (Grau, Thromb Res 1989; 53: 145) and it has been shown that these cells have specific receptors for urokinase and plasminogen (Miles, Thromb Haemostas 1987; 58: 936). The aim of this study was to analyse the presence of plasminogen activator inhibitor(s) in platelet-free suspensions of human peripheral blood monocytes and polymorphonuclear leukocytes (PMN). SDS-PAGE and reverse fibrin autography showed an inhibitory band of 50 kDa in the monocyte extracts (Triton X-100) but not in the PMN extracts. Urokinase (u-PA) was mixed with increasing amounts of monocyte extract for 10 min and the mixtures were added to 125Ifibrin coated wells containing plasminogen. A dose-dependent decrease in the u-PA fibrinolytic activity was observed. The amount of inhibition increased when the monocyte releasates were preincubated with u-PA (40% inhibition after 5 min preincubation and 80% after 15 min), indicating a direct interaction between this activator and an inhibitor(s). After SDS-PAGE of monocyte extracts, immunoblotting and peroxidase staining identified both PAI1 and PAI2, with an apparent molecular weight of 47-50 kDa. Monocyte-associated PAI1 formed complexes with single chain t-PA with a molecular mass 50 kDa higher than the molecular mass of the free PAI1. However, a significant amount of PAI remained unbound to t-PA. This inactive PAI1 could have come from a rapid inactivation of the primary active PAI1. These PAI1 and PAI2 detected in human monocytes may be transcendent in the regulation of the fibrinolytic system.

Defibrotide Inhibits Platelet Activation by Cathepsin G Released From Stimulated Polymorphonuclear Leukocytes

1992 ◽  
Vol 67 (06) ◽  
pp. 660-664 ◽  
Author(s):  
Virgilio Evangelista ◽  
Paola Piccardoni ◽  
Giovanni de Gaetano ◽  
Chiara Cerletti
Keyword(s):  
Platelet Activation ◽  
Polymorphonuclear Leukocytes ◽  
Direct Interaction ◽  
Cathepsin G ◽  
In Vivo Test ◽  
Cell Functions ◽  
Test Models ◽  
Antithrombotic Effects

SummaryDefibrotide is a polydeoxyribonucleotide with antithrombotic effects in experimental animal models. Most of the actions of this drug have been observed in in vivo test models but no effects have been reported in in vitro systems. In this paper we demonstrate that defibrotide interferes with polymorphonuclear leukocyte-induced human platelet activation in vitro. This effect was not related to any direct interaction with polymorphonuclear leukocytes or platelets, but was due to the inhibition of cathepsin G, the main biochemical mediator of this cell-cell cooperation. Since cathepsin G not only induces platelet activation but also affects some endothelial cell functions, the anticathepsin G activity of defibrotide could help to explain the antithrombotic effect of this drug.

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