Aminoglycerophospholipid flipping and P4-ATPases in Toxoplasma gondii.

Autor:	Chen K; Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany., Günay-Esiyok Ö; Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany., Klingeberg M; Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany., Marquardt S; Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany; Department of Experimental Biophysics, Faculty of Life Sciences, Humboldt University, Berlin, Germany., Pomorski TG; Department of Experimental Biophysics, Faculty of Life Sciences, Humboldt University, Berlin, Germany., Gupta N; Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany; Department of Biological Sciences, Birla Institute of Technology and Science Pilani (BITS-P), Hyderabad, India. Electronic address: Gupta.Nishith@hu-berlin.de.
Jazyk:	angličtina
Zdroj:	The Journal of biological chemistry [J Biol Chem] 2021 Jan-Jun; Vol. 296, pp. 100315. Date of Electronic Publication: 2021 Jan 21.
DOI:	10.1016/j.jbc.2021.100315
Abstrakt:	Lipid flipping in the membrane bilayers is a widespread eukaryotic phenomenon that is catalyzed by assorted P4-ATPases. Its occurrence, mechanism, and importance in apicomplexan parasites have remained elusive, however. Here we show that Toxoplasma gondii, an obligate intracellular parasite with high clinical relevance, can salvage phosphatidylserine (PtdSer) and phosphatidylethanolamine (PtdEtn) but not phosphatidylcholine (PtdCho) probes from its milieu. Consistently, the drug analogs of PtdCho are broadly ineffective in the parasite culture. NBD-PtdSer imported to the parasite interior is decarboxylated to NBD-PtdEtn, while the latter is not methylated to yield PtdCho, which confirms the expression of PtdSer decarboxylase but a lack of PtdEtn methyltransferase activity and suggests a role of exogenous lipids in membrane biogenesis of T. gondii. Flow cytometric quantitation of NBD-probes endorsed the selectivity of phospholipid transport and revealed a dependence of the process on energy and protein. Accordingly, our further work identified five P4-ATPases (TgP4-ATPase1-5), all of which harbor the signature residues and motifs required for phospholipid flipping. Of the four proteins expressed during the lytic cycle, TgP4-ATPase1 is present in the apical plasmalemma; TgP4-ATPase3 resides in the Golgi network along with its noncatalytic partner Ligand Effector Module 3 (TgLem3), whereas TgP4-ATPase2 and TgP4-ATPase5 localize in the plasmalemma as well as endo/cytomembranes. Last but not least, auxin-induced degradation of TgP4-ATPase1-3 impaired the parasite growth in human host cells, disclosing their crucial roles during acute infection. In conclusion, we show selective translocation of PtdEtn and PtdSer at the parasite surface and provide the underlying mechanistic and physiological insights in a model eukaryotic pathogen. Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article. (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)
Databáze:	MEDLINE
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