Scientific article
Open access

Apicomplexan rhomboids have a potential role in microneme protein cleavage during host cell invasion

Published inInternational Journal for Parasitology, vol. 35, no. 7, p. 747-756
Publication date2005

Apicomplexan parasites secrete transmembrane (TM) adhesive proteins as part of the process leading to host cell attachment and invasion. These microneme proteins are cleaved in their TM domains by an unidentified protease termed microneme protein protease 1 (MPP1). The cleavage site sequence (IA downward arrowGG), mapped in the Toxoplasma gondii microneme proteins TgMIC2 and TgMIC6, is conserved in microneme proteins of other apicomplexans including Plasmodium species. We report here the characterisation of novel T. gondii proteins belonging to the rhomboid family of intramembrane-cleaving serine proteases. T. gondii possesses six genes encoding rhomboid-like proteins. Four are localised along the secretory pathway and therefore constitute possible candidates for MPP1 activity. Toxoplasma rhomboids TgROM1, TgROM2 and TgROM5 cleave the TM domain of Drosophila Spitz, an established substrate for rhomboids from several species, demonstrating that they are active proteases. In addition, TgROM2 cleaves chimeric proteins that contain the TM domains of TgMIC2 and TgMIC12.

  • Animals
  • Blotting, Western/methods
  • Cell Adhesion Molecules/genetics/metabolism
  • Drosophila Proteins/metabolism
  • Enzyme Activation
  • Fluorescent Antibody Technique, Indirect
  • Membrane Proteins/genetics/metabolism
  • Microscopy, Confocal
  • Protozoan Proteins/genetics/metabolism
  • Serine Endopeptidases/metabolism
  • Toxoplasma/metabolism
  • Toxoplasmosis/metabolism/transmission
Citation (ISO format)
DOWSE, Timothy et al. Apicomplexan rhomboids have a potential role in microneme protein cleavage during host cell invasion. In: International Journal for Parasitology, 2005, vol. 35, n° 7, p. 747–756. doi: 10.1016/j.ijpara.2005.04.001
Main files (1)
Article (Accepted version)
ISSN of the journal0020-7519

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