Duodenal bicarbonate secretion: Eradication of Helicobacter pylori and duodenal structure and function in humans

1996 ◽  
Vol 110 (3) ◽  
pp. 705-716 ◽  
Author(s):  
DL Hogan ◽  
RC Rapier ◽  
A Dreilinger ◽  
MA Koss ◽  
PM Basuk ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Structure And Function ◽  
Bicarbonate Secretion ◽  
Duodenal Bicarbonate Secretion ◽  
And Function

scholarly journals Structure and function of the CagA oncoprotein from Helicobacter pylori

2014 ◽  
Vol 70 (a1) ◽  
pp. C839-C839
Author(s):  
Toshiya Senda ◽  
Miki Senda ◽  
Takeru Hayashi ◽  
Masanori Hatakeyama
Keyword(s):  
Helicobacter Pylori ◽  
Plasma Membrane ◽  
Structure And Function ◽  
Terminal Region ◽  
Oncogenic Signaling ◽  
Intrinsically Disordered ◽  
Arginine Residues ◽  
Function Relationship ◽  
Structure And Function Relationship ◽  
And Function

CagA is known as a major bacterial virulence determinant from Helicobacter pylori and is critical for gastric cancer. Upon delivery into the gastric epithelial cells, CagA localizes to the inner leaflet of the plasma membrane and promiscuously interacts with host proteins such as PAR1b and SHP2. The CagA-PAR1-SHP2 complex potentiates oncogenic signaling. Biochemical and physicochemical analyses revealed that CagA is comprises a structured N-terminal region (residues 1-876) and an intrinsically disordered C-terminal region (residues 877-1186). To understand the structure and function relationship of CagA, we determined the crystal structure of the N-terminal region (residues 1-876) of CagA [1]. The N-terminal CagA is rich in α-helices and composed of three domains. Domain I (residues 24-221) is linked to domain II (residues 303-644) by a disordered loop with about 80 amino acid residues. Domain II has a basic patch composed of 14 lysine and 2 arginine residues. Biological experiments revealed that the basic patch mediates the CagA-phosphatidylserine interaction to localize the inner face of the plasma membrane. In addition, we found that C-terminal disordered region forms a lariat-like loop by the interaction between NBS (residues 645 - 824) and CBS (residues 998 - 1038) in the disordered C-terminal region. The formation of the lariat-like loop facilitates promiscuous interaction of CagA with target protein such as SHP2.

scholarly journals Expression of Helicobacter pylori Vacuolating Toxin in Escherichia coli

2003 ◽  
Vol 71 (4) ◽  
pp. 2266-2271 ◽  
Author(s):  
Mark S. McClain ◽  
Timothy L. Cover
Keyword(s):  
Escherichia Coli ◽  
Helicobacter Pylori ◽  
Peptic Ulcer ◽  
Genetic Manipulation ◽  
Expression System ◽  
Structure And Function ◽  
Heterologous Expression System ◽  
Efficient System ◽  
Ulcer Disease ◽  
And Function

ABSTRACT VacA is a secreted toxin that plays a role in Helicobacter pylori colonization of the stomach and that contributes to the pathogenesis of peptic ulcer disease. Studies of VacA structure and function have been hindered by the lack of an efficient system for expression and genetic manipulation of this toxin. In this study, we developed methodology for expression of a functionally active VacA toxin in Escherichia coli. We then used a high-throughput screen to analyze a library of mutant toxins with pentapeptide insertions and identified six mutants that lacked the capacity to induce vacuolation of HeLa cells. The capacity to analyze VacA in this heterologous-expression system should greatly facilitate efforts to elucidate the structure and function of this toxin.

scholarly journals Helicobacter pylori disrupts gastric epithelial barrier structure and function in an MLCK and ROCK dependent fashion

2006 ◽  
Vol 20 (5) ◽  
Author(s):  
Tamia Kateri Lapointe ◽  
Pamela M. O'Connor ◽  
Jason P. Fedwick ◽  
Jon Meddings ◽  
Daniel Menard ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Structure And Function ◽  
Epithelial Barrier ◽  
Barrier Structure ◽  
And Function

Structure and function of neural networks in the retina

1988 ◽  
Vol 46 ◽  
pp. 26-27
Author(s):  
Peter Sterling
Keyword(s):  
Ganglion Cells ◽  
Three Dimensional ◽  
Structure And Function ◽  
Synaptic Connections ◽  
Visual Axis ◽  
One Dimensional ◽  
Cat Retina ◽  
Ultrathin Sections ◽  
And Function ◽  
Insight Into

The synaptic connections in cat retina that link photoreceptors to ganglion cells have been analyzed quantitatively. Our approach has been to prepare serial, ultrathin sections and photograph en montage at low magnification (˜2000X) in the electron microscope. Six series, 100-300 sections long, have been prepared over the last decade. They derive from different cats but always from the same region of retina, about one degree from the center of the visual axis. The material has been analyzed by reconstructing adjacent neurons in each array and then identifying systematically the synaptic connections between arrays. Most reconstructions were done manually by tracing the outlines of processes in successive sections onto acetate sheets aligned on a cartoonist's jig. The tracings were then digitized, stacked by computer, and printed with the hidden lines removed. The results have provided rather than the usual one-dimensional account of pathways, a three-dimensional account of circuits. From this has emerged insight into the functional architecture.

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