Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
31
pubmed:dateCreated
1992-12-1
pubmed:abstractText
Adenylate cyclase (AC) toxin from Bordetella pertussis penetrates eukaryotic cells and upon activation by calmodulin generates unregulated levels of intracellular cAMP. The process of toxin penetration into sheep erythrocytes was resolved into three consecutive steps including insertion, translocation, and intracellular cleavage. Insertion of the toxin into the cell membrane occurred over a wide temperature range (4-36 degrees C). In contrast, translocation of the toxin, i.e. transfer of the NH2-terminal catalytically active fragment across the membrane, occurred only above 20 degrees C and was highly temperature-dependent. While a single exposure of the toxin to Ca2+ was sufficient for its insertion into the plasma membrane, toxin translocation required exogenous Ca2+ at mM concentrations. Translocation was not affected by pretreatment of cells with trypsin, N-ethylmaleimide, and sodium carbonate at alkaline pH. The NH2-terminal fragment of the toxin was cleaved in the cell releasing the 45-kDa active AC into the cytosol. The cleavage was blocked by treatment of cells with N-ethylmaleimide. It is hypothesized that the COOH-terminal portion of the toxin creates in the membrane a channel through which the NH2-terminal fragment is translocated.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
267
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
22599-605
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Distinct steps in the penetration of adenylate cyclase toxin of Bordetella pertussis into sheep erythrocytes. Translocation of the toxin across the membrane.
pubmed:affiliation
Department of Clinical Microbiology, Hebrew University-Hadassah Medical School, Jerusalem, Israel.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't