Gold DA1,
Kaplan AD2,
Lis A2,
Bett GC3,
Rosowski EE1,
Cirelli KM1,
Bougdour A4,
Sidik SM5,
Beck JR6,
Lourido S7,
Egea PF8,
Bradley PJ6,
Hakimi MA4,
Rasmusson RL2,
Saeij JP9.
Abstract
Toxoplasma gondii is a protozoan pathogen in the phylum Apicomplexa that resides within an intracellular parasitophorous vacuole (PV) that is selectively permeable to small molecules through unidentified mechanisms. We have identified GRA17 as a Toxoplasma-secreted protein that localizes to the parasitophorous vacuole membrane (PVM) and mediates passive transport of small molecules across the PVM. GRA17 is related to the putative Plasmodium translocon protein EXP2 and conserved across PV-residing Apicomplexa. The PVs of GRA17-deficient parasites have aberrant morphology, reduced permeability to small molecules, and structural instability. GRA17-deficient parasites proliferate slowly and are avirulent in mice. These GRA17-deficient phenotypes are rescued by complementation with Plasmodium EXP2. GRA17 functions synergistically with a related protein, GRA23. Exogenous expression of GRA17 or GRA23 alters the membrane conductance properties of Xenopus oocytes in a manner consistent with a large non-selective pore. Thus, GRA17 and GRA23 provide a molecular basis for PVM permeability and nutrient access.
Copyright © 2015 Elsevier Inc. All rights reserved.
- PMID:
- 25974303
- [PubMed - as supplied by publisher]
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