scholarly journals Mechanisms of molecular transport through the urea channel of Helicobacter pylori

2013 ◽  
Vol 4 (1) ◽  
Author(s):  
Reginald McNulty ◽  
Jakob P. Ulmschneider ◽  
Hartmut Luecke ◽  
Martin B. Ulmschneider
Keyword(s):  
Helicobacter Pylori ◽  
Molecular Transport ◽  
Urea Channel

scholarly journals Mechanisms of Molecular Transport through the Proton-Gated Urea Channel of Helicobacter Pylori

2014 ◽  
Vol 106 (2) ◽  
pp. 448a
Author(s):  
Hartmut Luecke ◽  
Reginald McNulty ◽  
Martin Ulmschneider ◽  
Jacob Ulmschneider
Keyword(s):  
Helicobacter Pylori ◽  
Molecular Transport ◽  
Urea Channel

Acid Acclimation byHelicobacter pylori

Physiology ◽  
2005 ◽  
Vol 20 (6) ◽  
pp. 429-438 ◽  
Author(s):  
George Sachs ◽  
David L. Weeks ◽  
Yi Wen ◽  
Elizabeth A. Marcus ◽  
David R. Scott ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Helicobacter Pylori ◽  
Carbonic Anhydrase ◽  
Human Stomach ◽  
Peptic Ulcers ◽  
Acidic Media ◽  
Gram Negative ◽  
Urea Channel ◽  
Acid Acclimation ◽  
Unique Ability

Helicobacter pylori is a Gram-negative neutralophile associated with peptic ulcers and gastric cancer. It has a unique ability to colonize the human stomach by acid acclimation. It uses the pH-gated urea channel, UreI, to enhance urea access to intrabacterial urease and a membrane-anchored periplasmic carbonic anhydrase to regulate periplasmic pH to ~6.1 in acidic media, whereas other neutralophiles cannot regulate periplasmic pH and thus only transit the stomach.

scholarly journals Structure of the proton-gated urea channel from the gastric pathogen Helicobacter pylori

Nature ◽  
2012 ◽  
Vol 493 (7431) ◽  
pp. 255-258 ◽  
Author(s):  
David Strugatsky ◽  
Reginald McNulty ◽  
Keith Munson ◽  
Chiung-Kuang Chen ◽  
S. Michael Soltis ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Urea Channel ◽  
Gastric Pathogen

scholarly journals Sites of pH regulation of the urea channel of Helicobacter pylori

2001 ◽  
Vol 40 (6) ◽  
pp. 1249-1259 ◽  
Author(s):  
David L. Weeks ◽  
George Sachs
Keyword(s):  
Helicobacter Pylori ◽  
Ph Regulation ◽  
Urea Channel

A H+-Gated Urea Channel: The Link Between Helicobacter pylori Urease and Gastric Colonization

Science ◽  
2000 ◽  
Vol 287 (5452) ◽  
pp. 482-485 ◽  
Author(s):  
D. L. Weeks
Keyword(s):  
Helicobacter Pylori ◽  
Gastric Colonization ◽  
Urea Channel

scholarly journals Cytoplasmic Histidine Kinase (HP0244)-Regulated Assembly of Urease with UreI, a Channel for Urea and Its Metabolites, CO2, NH3, and NH4+, Is Necessary for Acid Survival of Helicobacter pylori

2009 ◽  
Vol 192 (1) ◽  
pp. 94-103 ◽  
Author(s):  
David R. Scott ◽  
Elizabeth A. Marcus ◽  
Yi Wen ◽  
Siddarth Singh ◽  
Jing Feng ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Histidine Kinase ◽  
Ph Sensor ◽  
Cytoplasmic Ph ◽  
Ph Homeostasis ◽  
Regulatory Complex ◽  
Cytoplasmic Acidification ◽  
Normal Human ◽  
Urea Channel ◽  
Urease Activation

ABSTRACT Helicobacter pylori colonizes the normal human stomach by maintaining both periplasmic and cytoplasmic pH close to neutral in the presence of gastric acidity. Urease activity, urea flux through the pH-gated urea channel, UreI, and periplasmic α-carbonic anhydrase are essential for colonization. Exposure to pH 4.5 for up to 180 min activates total bacterial urease threefold. Within 30 min at pH 4.5, the urease structural subunits, UreA and UreB, and the Ni2+ insertion protein, UreE, are recruited to UreI at the inner membrane. Formation of this complex and urease activation depend on expression of the cytoplasmic sensor histidine kinase, HP0244. Its deletion abolishes urease activation and assembly, impairs cytoplasmic and periplasmic pH homeostasis, and depolarizes the cells, with an ∼7-log loss of survival at pH 2.5, even in 10 mM urea. Associated with this assembly, UreI is able to transport NH3, NH4 +, and CO2, as shown by changes in cytoplasmic pH following exposure to NH4Cl or CO2. To be able to colonize cells in the presence of the highly variable pH of the stomach, the organism expresses two pH-sensor histidine kinases, one, HP0165, responding to a moderate fall in periplasmic pH and the other, HP0244, responding to cytoplasmic acidification at a more acidic medium pH. Assembly of a pH-regulatory complex of active urease with UreI provides an advantage for periplasmic buffering.

Urel-encoded urea channel of Helicobacter pylori is essential for both gastric colonization of and persistence in gerbils

2001 ◽  
Vol 120 (5) ◽  
pp. A55 ◽  
Author(s):  
Guido Hanauer ◽  
Lutz Hermann ◽  
Marina Rektorschek ◽  
Stefan Postius ◽  
George Sachs ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Gastric Colonization ◽  
Urea Channel

scholarly journals Solute Specificity and Transport Kinetics of the Urea Channel from Helicobacter Pylori

2012 ◽  
Vol 102 (3) ◽  
pp. 245a
Author(s):  
Lawrence R. Gray ◽  
Sean Gu ◽  
Shahram Khademi
Keyword(s):  
Helicobacter Pylori ◽  
Transport Kinetics ◽  
Urea Channel ◽  
Kinetics Of

Urel-encoded urea channel of Helicobacter pylori is essential for both gastric colonization of and persistence in gerbils

2001 ◽  
Vol 120 (5) ◽  
pp. A55-A55
Author(s):  
G HANAUER ◽  
L HERMANN ◽  
M REKTORSCHEK ◽  
S POSTIUS ◽  
G SACHS ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Gastric Colonization ◽  
Urea Channel
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