title: Calcium entry in Toxoplasma gondii and its enhancing effect of invasion-linked traits.
abstract: During invasion and egress from their host cells, Apicomplexan parasites face sharp changes in the surrounding calcium ion (Ca(2+)) concentration. Our work with Toxoplasma gondii provides evidence for Ca(2+) influx from the extracellular milieu leading to cytosolic Ca(2+) increase and enhancement of virulence traits, such as gliding motility, conoid extrusion, microneme secretion, and host cell invasion. Assays of Mn(2+) and Ba(2+) uptake do not support a canonical store-regulated Ca(2+) entry mechanism. Ca(2+) entry was blocked by the L-type Ca(2+) channel inhibitor nifedipine and stimulated by the increase in cytosolic Ca(2+) and by the specific L-type Ca(2+) channel agonist Bay K-8644. Our results demonstrate that Ca(2+) entry is critical for parasite virulence. We propose a regulated Ca(2+) entry mechanism activated by cytosolic Ca(2+) that has an enhancing effect on invasion-linked traits.
authors.affiliation: From the Center for Tropical and Emerging Global Diseases and.
authors.forename: Douglas A
authors.initials: DA
authors.lastname: Pace
authors.affiliation: From the Center for Tropical and Emerging Global Diseases and the Department of Cellular Biology, University of Georgia, Athens, Georgia 30602 and.
authors.forename: Ciara A
authors.initials: CA
authors.lastname: McKnight
authors.affiliation: From the Center for Tropical and Emerging Global Diseases and the College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Liu
authors.affiliation: From the Center for Tropical and Emerging Global Diseases and.
authors.forename: Veronica
authors.initials: V
authors.lastname: Jimenez
authors.affiliation: From the Center for Tropical and Emerging Global Diseases and the Department of Cellular Biology, University of Georgia, Athens, Georgia 30602 and smoreno@uga.edu.
authors.forename: Silvia N J
authors.initials: SN
authors.lastname: Moreno
mesh_terms: D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester / Q000494:pharmacology; D000818:Animals; D001464:Barium / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D002120:Calcium Channel Agonists / Q000494:pharmacology; D020746:Calcium Channels, L-Type / Q000378:metabolism*; D006801:Humans; D008345:Manganese / Q000378:metabolism; D015800:Protozoan Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D040641:Quantitative Trait Loci / Q000502:physiology*; D014122:Toxoplasma / Q000378:metabolism* / Q000472:pathogenicity*; D014123:Toxoplasmosis / Q000378:metabolism
chemical_list: D002120:Calcium Channel Agonists; D020746:Calcium Channels, L-Type; D015800:Protozoan Proteins; D001464:Barium; D008345:Manganese; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D002118:Calcium
keywords: Calcium; Cell Invasion; Conoid Extrusion; Fluorescence; Gliding Motility; Nifedipine; Parasite; Protozoan; Signaling; Toxoplasma gondii