Cell line-specific transcriptional activation of the promoter of the human guanylyl cyclase C/heat-stable enterotoxin receptor gene

1996 ◽  
Vol 1305 (1-2) ◽  
pp. 7-10 ◽  
Author(s):  
Elizabeth A. Mann ◽  
Mary Lynn Jump ◽  
Ralph A. Giannella
Keyword(s):  
Cell Line ◽  
Guanylyl Cyclase ◽  
Transcriptional Activation ◽  
Receptor Gene ◽  
Guanylyl Cyclase C ◽  
Heat Stable

Identification of a binding region onEscherichia coli heat-stable enterotoxin to intestinal guanylyl cyclase C

1997 ◽  
Vol 4 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Makoto Hasegawa ◽  
Yuki Kawano ◽  
Kazuya Matsumoto ◽  
Yuji Hidaka ◽  
Takashi Sato ◽  
...  
Keyword(s):  
Guanylyl Cyclase ◽  
Guanylyl Cyclase C ◽  
Binding Region ◽  
Heat Stable

scholarly journals A Novel PDZ Protein Regulates the Activity of Guanylyl Cyclase C, the Heat-stable Enterotoxin Receptor

2002 ◽  
Vol 277 (25) ◽  
pp. 22934-22941 ◽  
Author(s):  
Robert O. Scott ◽  
William R. Thelin ◽  
Sharon L. Milgram
Keyword(s):  
Guanylyl Cyclase ◽  
Guanylyl Cyclase C ◽  
Heat Stable ◽  
Pdz Protein

Proguanylin secretion and the role of negative-feedback inhibition in a villous epithelial cell line

2002 ◽  
Vol 283 (3) ◽  
pp. G695-G702 ◽  
Author(s):  
Jeffrey A. Rudolph ◽  
Jennifer A. Hawkins ◽  
Mitchell B. Cohen
Keyword(s):  
Epithelial Cells ◽  
Cell Line ◽  
Negative Feedback ◽  
Guanylyl Cyclase ◽  
Feedback Inhibition ◽  
Signal Transduction Pathway ◽  
Regulatory System ◽  
Epithelial Cell Line ◽  
Guanylyl Cyclase C

The mechanisms of proguanylin synthesis and secretion in the intestine are incompletely understood. We designed an in vitro model to study proguanylin secretion in a model of intestinal villous epithelial cells. The C2/bbe1 cell line, a differentiated subclone of Caco-2 cells, was used to examine the direction of proguanylin secretion and the potential for feedback regulation via activators of the guanylyl cyclase C signal transduction pathway. When cells were grown on Transwell inserts, proguanylin was secreted into the apical and basolateral media, consistent with other models of intestinal guanylin secretion. Proguanylin synthesis and secretion were not decreased on activation of guanylyl cyclase C-mediated chloride secretion, implying a regulatory system other than negative-feedback inhibition. These data describe the use of C2/bbe1 cells as a model for proguanylin secretion in villous epithelial cells and demonstrate their potential use for the study of the regulatory mechanisms governing proguanylin synthesis and secretion.

Differential processing of guanylyl cyclase C along villus-crypt axis of rat small intestine

1997 ◽  
Vol 272 (6) ◽  
pp. C1995-C2004 ◽  
Author(s):  
L. A. Scheving ◽  
K. M. Chong
Keyword(s):  
Guanylyl Cyclase ◽  
Limited Proteolysis ◽  
Structural Heterogeneity ◽  
Proteolytic Processing ◽  
Enterotoxigenic Escherichia Coli ◽  
Guanylyl Cyclase C ◽  
Heat Stable ◽  
Molecular Events ◽  
Cell Fractions ◽  
Carboxy Terminal

Many strains of enterotoxigenic Escherichia coli produce a heat-stable peptide enterotoxin (STa) that binds to the intestinal receptor guanylyl cyclase C (GC-C). STa receptors are structurally heterogeneous, but the molecular events causing this heterogeneity remain obscure. We examined the influence of cell position along the villus-crypt axis on STa receptor heterogeneity by fractionating EDTA-dissociated cells that detached in a villus-to-crypt direction. STa affinity labeling experiments revealed that the initially released villus “tip” fraction had four major STa binding proteins (STBPs), with relative molecular weight (M(r)) of 150,000, 135,000, 125,000, and 95,000, that did not react with a GC-C carboxy-terminal antibody. Yet succeeding villus cell fractions had major immunoreactive STBPs with M(r) of 275,000 and 250,000. Limited proteolysis of these larger GC-C isoforms produced 1) smaller STBPs that had M(r) similar to those in the initial villus fraction, 2) a 65,000 M(r) protein GC-C isoform that did not bind STa, and 3) elevated basal and STa-induced cyclase activity. Our data show that STBP structural heterogeneity in the intact intestine arises largely from multisite proteolytic processing of GC-C.

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