Detection and Localization of a Ca2+-ATPase Activity in Toxoplasma gondii

Cell Structure and Function

André Bouchot⁴  Henriette Burlet⁴  Laurence Kilian¹  Nathalie Pezzella-D' Alessandro⁴  Annie Bonhomme⁴  Michel Pluot²  Jean-Michel Pinon⁴  Pierre Bonhomme¹  Jean-David Jaillet⁴  Jorge-Enrique Gomez-Marin³  Patrice Laquerriere¹ 

[1] Laboratoire de Microscopie Electronique Analytique et Quantitative, IFR 53;Laboratoire d'Anatomie-Pathologique, Hôpital Robert Debré;Groupo de Pathologia Infecciosa, Departmento de Medicina Interna, Hospital San Juan de Dios, Universidad Nacional de Colombia;UPRES EA 2070 et Laboratoire de Parasitologie-Mycologie

关键词: Ca2+;    Mg2+;    ATPase;    Toxoplasma gondii;    cerium precipitation;    X-ray microanalysis;    immunolocalization;   

DOI  :  10.1247/csf.26.49

学科分类：分子生物学，细胞生物学和基因

来源: Japan Society for Cell Biology

【 摘 要 】

References(59)Cited-By(5)Toxoplasma gondii, the agent causing toxoplasmosis, is an obligate intracellular protozoan parasite. A calcium signal appears to be essential for intracellular transduction during the active process of host cell invasion. We have looked for a Ca2+-transport ATPase in tachyzoites and found Ca2+-ATPase activity (11-22 nmol Pi liberated/mg protein/min) in the tachyzoite membrane fraction. This ATP-dependent activity was stimulated by Ca2+ and Mg2+ ions and by calmodulin, and was inhibited by pump inhibitors (sodium orthovanadate or thapsigargin). We used cytochemistry and X-ray microanalysis of cerium phosphate precipitates and immunolabelling to find the Ca2+, Mg2+-ATPase. It was located mainly in the membrane complex, the conoid, nucleus, secretory organelles (rhoptries, dense granules) and in vesicles with a high calcium concentration. Thus, Toxoplasma gondii possesses Ca2+-pump ATPase (Ca2+, Mg2+-ATPase) as do eukaryotic cells.

【 授权许可】

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