scholarly journals The Kinase Activity of the Helicobacter pylori Asp-tRNAAsn/Glu-tRNAGln Amidotransferase Is Sensitive to Distal Mutations in Its Putative Ammonia Tunnel

Biochemistry ◽  
2011 ◽  
Vol 51 (1) ◽  
pp. 273-285 ◽  
Author(s):  
Liangjun Zhao ◽  
Sajeewa W. Dewage ◽  
Michael J. Bell ◽  
Keng-Ming Chang ◽  
Shirin Fatma ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Kinase Activity ◽  
Ammonia Tunnel

scholarly journals Paxillin is a novel cellular target for converging Helicobacter pylori-induced cellular signaling

2011 ◽  
Vol 301 (4) ◽  
pp. G601-G611 ◽  
Author(s):  
Fazal H. Tabassam ◽  
David Y. Graham ◽  
Yoshio Yamaoka
Keyword(s):  
Helicobacter Pylori ◽  
Kinase Activity ◽  
Stress Fiber ◽  
Fiber Formation ◽  
Actin Stress Fiber ◽  
Stress Fiber Formation ◽  
Cellular Target ◽  
H Pylori ◽  
Actin Stress Fiber Formation ◽  
Cag Pai

Paxillin is involved in the regulation of Helicobacter pylori -mediated gastric epithelial cell motility. We investigated the signaling pathways regulating H. pylori -induced paxillin phosphorylation and the effect of the H. pylori virulence factors cag pathogenicity island (PAI) and outer inflammatory protein (OipA) on actin stress fiber formation, cell phenotype, and IL-8 production. Gastric cell infection with live H. pylori induced site-specific phosphorylation of paxillin tyrosine (Y) 31 and Y118 in a time- and concentration-dependent manner. Activated paxillin localized in the cytoplasm at the tips of H. pylori -induced actin stress fibers. Isogenic oipA mutants significantly reduced paxillin phosphorylation at Y31 and Y118 and reduced actin stress fiber formation. In contrast, cag PAI mutants only inhibited paxillin Y118 phosphorylation. Silencing of epidermal growth factor receptor (EGFR), focal adhesion kinase (FAK), or protein kinase B (Akt) expression by small-interfering RNAs or inhibiting kinase activity of EGFR, Src, or phosphatidylinositol 3-kinase (PI3K) markedly reduced H. pylori -induced paxillin phosphorylation and morphologic alterations. Reduced FAK expression or lack of Src kinase activity suppressed H. pylori -induced IL-8 production. Compared with infection with the wild type, infection with the cag PAI mutant and oipA mutant reduced IL-8 production by nearly 80 and 50%. OipA-induced IL-8 production was FAK- and Src-dependent, although a FAK/Src-independent pathway for IL-8 production also exists, and the cag PAI may be mainly involved in this pathway. We propose paxillin as a novel cellular target for converging H. pylori -induced EGFR, FAK/Src, and PI3K/Akt signaling to regulate cytoskeletal reorganization and IL-8 production in part, thus contributing to the H. pylori -induced diseases.

scholarly journals Cooperation of two distinct coupling proteins creates chemosensory network connections

2017 ◽  
Vol 114 (11) ◽  
pp. 2970-2975 ◽  
Author(s):  
Samar Abedrabbo ◽  
Juan Castellon ◽  
Kieran D. Collins ◽  
Kevin S. Johnson ◽  
Karen M. Ottemann
Keyword(s):  
Helicobacter Pylori ◽  
Signal Amplification ◽  
Kinase Activity ◽  
Bacterial Chemotaxis ◽  
Higher Order ◽  
Scaffold Proteins ◽  
Receiver Domain ◽  
Network Connections ◽  
Coupling Protein ◽  
Chemotaxis System

Although it is appreciated that bacterial chemotaxis systems rely on coupling, also called scaffold, proteins to both connect input receptors with output kinases and build interkinase connections that allow signal amplification, it is not yet clear why many systems use more than one coupling protein. We examined the distinct functions for multiple coupling proteins in the bacterial chemotaxis system of Helicobacter pylori, which requires two nonredundant coupling proteins for chemotaxis: CheW and CheV1, a hybrid of a CheW and a phosphorylatable receiver domain. We report that CheV1 and CheW have largely redundant abilities to interact with chemoreceptors and the CheA kinase, and both similarly activated CheA’s kinase activity. We discovered, however, that they are not redundant for formation of the higher order chemoreceptor arrays that are known to form via CheA–CheW interactions. In support of this possibility, we found that CheW and CheV1 interact with each other and with CheA independent of the chemoreceptors. Therefore, it seems that some microbes have modified array formation to require CheW and CheV1. Our data suggest that multiple coupling proteins may be used to provide flexibility in the chemoreceptor array formation.

scholarly journals Serine Phosphorylation of Cortactin Controls Focal Adhesion Kinase Activity and Cell Scattering Induced by Helicobacter pylori

2011 ◽  
Vol 9 (6) ◽  
pp. 520-531 ◽  
Author(s):  
Nicole Tegtmeyer ◽  
Ruth Wittelsberger ◽  
Roland Hartig ◽  
Silja Wessler ◽  
Narcisa Martinez-Quiles ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Focal Adhesion Kinase ◽  
Focal Adhesion ◽  
Kinase Activity ◽  
Serine Phosphorylation ◽  
Cell Scattering ◽  
Focal Adhesion Kinase Activity

Correction to The Kinase Activity of the Helicobacter pyloriAsp-tRNAAsn/Glu-tRNAGln Amidotransferase Is Sensitive to Distal Mutations in Its Putative Ammonia Tunnel

Biochemistry ◽  
2013 ◽  
Vol 52 (13) ◽  
pp. 2381-2381
Author(s):  
Liangjun Zhao ◽  
Sajeewa W. Dewage ◽  
Michael J. Bell ◽  
Keng-Ming Chang ◽  
Shirin Fatma ◽  
...  
Keyword(s):  
Kinase Activity ◽  
Ammonia Tunnel

The rod-to-coccoid body transformation in cultures of Helicobacter pylori

1990 ◽  
Vol 48 (3) ◽  
pp. 626-627
Author(s):  
A. R. Crooker ◽  
W. G. Kraft ◽  
T. L. Beard ◽  
M. C. Myers
Keyword(s):  
Helicobacter Pylori ◽  
Growth Cycle ◽  
Negative Bacterium ◽  
Body Formation ◽  
Coccoid Form ◽  
Spiral Form ◽  
Prolonged Culture ◽  
H Pylori ◽  
Upper Gastrointestinal

Helicobacter pylori is a microaerophilic, gram-negative bacterium found in the upper gastrointestinal tract of humans. There is strong evidence that H. pylori is important in the etiology of gastritis; the bacterium may also be a major predisposing cause of peptic ulceration. On the gastric mucosa, the organism exists as a spiral form with one to seven sheathed flagella at one (usually) or both poles. Short spirals were seen in the first successful culture of the organism in 1983. In 1984, Marshall and Warren reported a coccoid form in older cultures. Since that time, other workers have observed rod and coccal forms in vitro; coccoid forms predominate in cultures 3-7 days old. We sought to examine the growth cycle of H. pylori in prolonged culture and the mode of coccoid body formation.

DYSPEPSIA SYNDROME AND HELICOBACTER PYLORI INFECTION IN END STAGE RENAL FAILURE

2000 ◽  
Vol 15 (12) ◽  
pp. H2-H2
Author(s):  
IS Mertasudira ◽  
JR Saketi ◽  
A. Djumhana ◽  
J. Widjojo ◽  
SA Abdurachman
Keyword(s):  
Renal Failure ◽  
Helicobacter Pylori ◽  
Helicobacter Pylori Infection ◽  
End Stage Renal Failure ◽  
End Stage

Mouse model of gastric infection with cytotoxin-expressing strain of Helicobacter pylori in studying of pathogenesis of chronic gastric ulcer

1998 ◽  
Vol 13 (11-s4) ◽  
pp. S178-S184 ◽  
Author(s):  
PETER KONTUREK ◽  
TOMASZ BRZOZOWSKI ◽  
STANISLAW KONTUREK ◽  
ELZBIETA KARCZEWSKA ◽  
ROBERT PAJDO ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Gastric Ulcer ◽  
Mouse Model ◽  
Chronic Gastric Ulcer
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