Linked Life Data

11207555

Source:http://linkedlifedata.com/resource/pubmed/id/11207555

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2001-3-9
pubmed:abstractText
Toxoplasma gondii is an obligate intracellular parasite that actively invades a wide variety of vertebrate cells, although the basis of its pervasive cell invasion is not completely understood. Here, we demonstrate, using several independent assays, that Toxoplasma invasion of host cells is tightly coupled to the release of proteins stored within apical secretory granules called micronemes. Both microneme secretion and cell invasion were highly temperature dependent, and partial depletion of microneme resulted in a transient loss of infectivity. Chelation of parasite intracellular calcium strongly inhibited both microneme release and invasion of host cells, and this effect was partially reversed by raising intracellular calcium using the ionophore A23187. We also provide evidence that a staurosporine-sensitive kinase activity regulates microneme discharge and is required for parasite invasion of host cells. Additionally, we demonstrate that, during apical attachment to the host cell, the micronemal protein MIC2 is released at the junction between the parasite and the host cell. During invasion, MIC2 is successively translocated towards the posterior end of the parasite and is shed before entry of the parasite into the vacuole. Furthermore, we show that the full-length cellular form of MIC2, but not the proteolytically modified secreted form of MIC2, binds specifically to host cells. Collectively, these observations strongly imply that micronemal proteins play a role in Toxoplasma invasion of host cells.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
1462-5814
pubmed:author
pubmed:issnType
Print
pubmed:volume
1
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
225-35
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Secretion of micronemal proteins is associated with toxoplasma invasion of host cells.
pubmed:affiliation
Department of Molecular Microbiology, Washington University School of Medicine, St Louis, MO 63110, USA. vcarruth@jhsph.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.