Linked Life Data

3350812

Source:http://linkedlifedata.com/resource/pubmed/id/3350812

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
1988-5-2
pubmed:abstractText
Translocation of diphtheria toxin (DT) or ricin to the cytosol is the rate-limiting step responsible for (pseudo) first-order decline in protein synthesis observed in intoxicated cell populations. The requirements for energy utilization in the translocation of both toxins are examined by perturbing the intoxication during this period of protein synthesis decline. Translocation of either toxin is blocked at 4 degrees C and requires energy. Ricin translocation is tightly coupled to ATP hydrolysis with no involvement of membrane potential. Cell depolarization slows the rate of DT translocation but does not block completely. Elimination of transmembrane pH gradients alone does not affect DT translocation; however, in combination with depolarization, translocation is blocked virtually completely. Energy requirements for DT intoxication are mediated by establishing a plasma membrane potential and a pH gradient across some cellular membrane. It is proposed that a postendocytotic vesicle containing processed DT fuses with the plasma membrane. Either component of the proton motive force across the plasma membrane then drives DT translocation. Ricin apparently utilizes a different energy coupling mechanism at a different intracellular site, thus demonstrating toxin specificity in the translocation mechanism.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
263
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4773-81
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Energy requirements for diphtheria toxin translocation are coupled to the maintenance of a plasma membrane potential and a proton gradient.
pubmed:affiliation
Laboratory of Molecular Biology, National Institute of Mental Health, Bethesda, Maryland 20892.
pubmed:publicationType
Journal Article