Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2011-2-21
pubmed:abstractText
Bacterial exotoxins exploit protein transport pathways of their mammalian target cells to deliver their enzymatic active moieties into the cytosol. There, they modify their specific substrate molecules resulting in cell damage and the clinical symptoms characteristic for each individual toxin. We have investigated the cellular uptake of the binary actin ADP-ribosylating C2 toxin from Clostridium botulinum and the binary lethal toxin from Bacillus anthracis, a metalloprotease. Both toxins are composed of a binding/translocation component and a separate enzyme component. During cellular uptake, the binding/translocation components form pores in membranes of acidified endosomes, and the enzyme components translocate as unfolded proteins through the pores into the cytosol. We found by using specific pharmacological inhibitors that the host cell chaperone Hsp90 and the peptidyl-prolyl cis/trans isomerase cyclophilin A are crucial for membrane translocation of the enzyme component of the C2 toxin but not of the lethal toxin, although the structures of the binding/translocation components and the overall uptake mechanisms of both toxins are widely comparable. In conclusion, the new findings imply that Hsp90 and cyclophilin function selectively in promoting translocation of certain bacterial toxins depending on the enzyme domains of the individual toxins. The targeted pharmacological inhibition of individual host cell chaperones/PPIases prevents uptake of certain bacterial exotoxins into the cytosol of mammalian cells and thus protects cells from intoxication. Such substances could represent attractive lead substances for development of novel therapeutics to prevent toxic effects during infection with toxin-producing bacteria.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1432-1912
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
383
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
237-45
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Exploring the role of host cell chaperones/PPIases during cellular up-take of bacterial ADP-ribosylating toxins as basis for novel pharmacological strategies to protect mammalian cells against these virulence factors.
pubmed:affiliation
Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Albert-Einstein-Allee 11, 89081, Ulm, Germany. holger.barth@uni-ulm.de
pubmed:publicationType
Journal Article, Review, Research Support, Non-U.S. Gov't