Interaction of heat-stable enterotoxins with human colonic (T84) cells: modulation of the activation of guanylyl cyclase.
Heat-stable enterotoxins (ST) activate guanylyl cyclase in T84 cells, rapidly and specifically. Activation is monitored by cGMP production and occurs at lower concentrations of ST than required for eliciting fluid accumulation in suckling mice. Atrial natriuretic factor (ANF) neither activates guanylyl cyclase nor modulates the response to ST in T84 cells, indicating the absence of receptors for ANF on T84 cells. Monitoring the production of cGMP under conditions known to alter fluid accumulation in suckling mice is an accurate and quantifiable assay of ST activity and its interaction with the receptor. STs produced by Escherichia coli, Vibrio cholerae non-01 and Yersinia enterocolitica individually produce elevated levels of cGMP in T84 cells, but to differing extents, suggesting that this model system can be used to elucidate the different events of ST-receptor interactions at the molecular level.
Astra Research Centre, Bangalore, India.
S S
SS
Visweswariah
G
G
Shanthi
T S
TS
Balganesh
D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies / Q000276:immunology; D009320:Atrial Natriuretic Factor / Q000378:metabolism; D002478:Cells, Cultured; D003106:Colon / Q000166:cytology; D004768:Enterotoxins / Q000276:immunology / Q000378:metabolism*; D004789:Enzyme Activation; D006162:Guanylate Cyclase / Q000378:metabolism*; D006358:Hot Temperature; D006801:Humans; D007413:Intestinal Mucosa / Q000166:cytology / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D011956:Receptors, Cell Surface / Q000378:metabolism; D000074261:Receptors, Enterotoxin; D050705:Receptors, Guanylate Cyclase-Coupled; D018000:Receptors, Peptide
D000906:Antibodies; D004768:Enterotoxins; D011956:Receptors, Cell Surface; D018000:Receptors, Peptide; D009320:Atrial Natriuretic Factor; D006162:Guanylate Cyclase; D000074261:Receptors, Enterotoxin; D050705:Receptors, Guanylate Cyclase-Coupled