spacer gif spacer gif spacer gif spacer gif spacer gif
QUICK SEARCH:   [advanced]


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Maddrell, S. H.
Right arrow Articles by Knowles, B. H.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Maddrell, S. H.
Right arrow Articles by Knowles, B. H.

Journal of Cell Science, Vol 94, Issue 3 601-608, Copyright © 1989 by Company of Biologists

JOURNAL ARTICLES

Action of activated 27,000 Mr toxin from Bacillus thuringiensis var. israelensis on Malpighian tubules of the insect, Rhodnius prolixus

SH Maddrell, JA Overton, DJ Ellar and BH Knowles
AFRC Unit of Insect Neurophysiology and Pharmacology, Department of Zoology, Cambridge, England.

The action of activated 27,000 Mr toxin from Bacillus thuringiensis var. israelensis (Bti toxin) on Malpighian tubules of Rhodnius prolixus has been investigated. Its binding to the tubules is slowed by low temperature but is not prevented even at 0 degree C. The binding is less effective at pH 10 than at pH7. Pretreatment of the tubules with 0.1 mmol l-1 ouabain or bumetanide or 1 mumol l-1 5-hydroxytryptamine did not affect the toxicity of the toxin. The toxin causes very large changes in the trans-epithelial potential difference; it changes from 40 mV, lumen negative, often to more than 100 mV, lumen positive. This reflects an initial collapse of the potential of the basal cell membrane, followed by a large positive-going potential change at the luminal cell membrane. Just prior to the effects of the toxin on rapid fluid secretion, the basal cell membrane becomes permeable to sucrose molecules. Raffinose at 170 mmol l-1 in the bathing solution does not protect the tubules from Bti toxin action but dextran, Mr5000, at 60 mmol l-1 significantly delayed failure of fluid secretion and, even more, the onset of staining of the tubule cells with Trypan Blue. Exposing tubules to saline that is calcium-free and/or magnesium-free, or has a composition adjusted to be similar to that of the intracellular milieu, does not affect the time course of failure of fluid secretion induced by the toxin. There is no evidence that effective aggregates of Bti toxin molecules are formed in concentrated solutions.(ABSTRACT TRUNCATED AT 250 WORDS)


This article has been cited by other articles:


Home page
 Appl. Environ. Microbiol.Home page
P. Butko
Cytolytic Toxin Cyt1A and Its Mechanism of Membrane Damage: Data and Hypotheses
Appl. Envir. Microbiol., May 1, 2003; 69(5): 2415 - 2422.
[Full Text] [PDF]

Home page
 Microbiol. Mol. Biol. Rev.Home page
E. Schnepf, N. Crickmore, J. Van Rie, D. Lereclus, J. Baum, J. Feitelson, D. R. Zeigler, and D. H. Dean
Bacillus thuringiensis and Its Pesticidal Crystal Proteins
Microbiol. Mol. Biol. Rev., September 1, 1998; 62(3): 775 - 806.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
E. Gazit and Y. Shai
The Assembly and Organization of the alpha5 and alpha7 Helices from the Pore-forming Domain of Bacillusthuringiensis [IMAGE]-Endotoxin
J. Biol. Chem., February 10, 1995; 270(6): 2571 - 2578.
[Abstract] [Full Text] [PDF]


© The Company of Biologists Ltd 1989