Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
Pt 24
pubmed:dateCreated
2004-11-11
pubmed:abstractText
Apicomplexans such as Toxoplasma gondii actively invade host cells using a unique parasite-dependent mechanism termed gliding motility. Calcium-mediated protein secretion by the parasite has been implicated in this process, but the precise role of calcium signaling in motility remains unclear. Here we used calmidazolium as a tool to stimulate intracellular calcium fluxes and found that this drug led to enhanced motility by T. gondii. Treatment with calmidazolium increased the duration of gliding and resulted in trails that were twice as long as those formed by control parasites. Calmidazolium also increased microneme secretion by T. gondii, and studies with a deletion mutant of the accessory protein m2AP specifically implicated that adhesin MIC2 was important for gliding. The effects of calmidazolium on gliding and secretion were due to increased release of calcium from intracellular stores and calcium influx from the extracellular milieu. In addition, we demonstrate that calmidazolium-stimulated increases in intracellular calcium were highly dynamic, and that rapid fluxes in calcium levels were associated with parasite motility. Our studies suggest that oscillations in intracellular calcium levels may regulate microneme secretion and control gliding motility in T. gondii.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0021-9533
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
117
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5739-48
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:15507483-Animals, pubmed-meshheading:15507483-Calcium, pubmed-meshheading:15507483-Calmodulin, pubmed-meshheading:15507483-Electrophoresis, Polyacrylamide Gel, pubmed-meshheading:15507483-Enzyme Inhibitors, pubmed-meshheading:15507483-Fibroblasts, pubmed-meshheading:15507483-Fluorescent Antibody Technique, Indirect, pubmed-meshheading:15507483-Gene Deletion, pubmed-meshheading:15507483-Humans, pubmed-meshheading:15507483-Imidazoles, pubmed-meshheading:15507483-Membrane Proteins, pubmed-meshheading:15507483-Microscopy, Fluorescence, pubmed-meshheading:15507483-Microscopy, Video, pubmed-meshheading:15507483-Movement, pubmed-meshheading:15507483-Oscillometry, pubmed-meshheading:15507483-Protozoan Proteins, pubmed-meshheading:15507483-Signal Transduction, pubmed-meshheading:15507483-Time Factors, pubmed-meshheading:15507483-Toxoplasma, pubmed-meshheading:15507483-beta-Galactosidase
pubmed:year
2004
pubmed:articleTitle
Calcium-mediated protein secretion potentiates motility in Toxoplasma gondii.
pubmed:affiliation
Department of Molecular Microbiology, Washington University School of Medicine, 660 South Euclid Avenue, St Louis, MO 63110, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural