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Chen K, Huang X, Distler U, Tenzer S, Günay-Esiyok Ö, Gupta N. Apically-located P4-ATPase1-Lem1 complex internalizes phosphatidylserine and regulates motility-dependent invasion and egress in Toxoplasma gondii. Comput Struct Biotechnol J 2023; 21:1893-1906. [PMID: 36936814 PMCID: PMC10015115 DOI: 10.1016/j.csbj.2023.02.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 02/17/2023] [Accepted: 02/17/2023] [Indexed: 02/22/2023] Open
Abstract
The membrane asymmetry regulated by P4-ATPases is crucial for the functioning of eukaryotic cells. The underlying spatial translocation or flipping of specific lipids is usually assured by respective P4-ATPases coupled to conforming non-catalytic subunits. Our previous work has identified five P4-ATPases (TgP4-ATPase1-5) and three non-catalytic partner proteins (TgLem1-3) in the intracellular protozoan pathogen, Toxoplasma gondii. However, their flipping activity, physiological relevance and functional coupling remain unknown. Herein, we demonstrate that TgP4-ATPase1 and TgLem1 work together to translocate phosphatidylserine (PtdSer) during the lytic cycle of T. gondii. Both proteins localize in the plasma membrane at the invasive (apical) end of its acutely-infectious tachyzoite stage. The genetic knockout of P4-ATPase1 and conditional depletion of Lem1 in tachyzoites severely disrupt the asexual reproduction and translocation of PtdSer across the plasma membrane. Moreover, the phenotypic analysis of individual mutants revealed a requirement of lipid flipping for the motility, egress and invasion of tachyzoites. Not least, the proximity-dependent biotinylation and reciprocal immunoprecipitation assays demonstrated the physical interaction of P4-ATPase1 and Lem1. Our findings disclose the mechanism and significance of PtdSer flipping during the lytic cycle and identify the P4-ATPase1-Lem1 heterocomplex as a potential drug target in T. gondii.
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Key Words
- BSA, bovine serum albumin
- CDC50, Cell Division Control 50
- COS, crossover sequence
- Cdc50
- DAPI, 4′,6-diamidino-2-phenylindole
- DHFR-TS, dihydrofolate reductase – thymidylate synthase
- HFF, human foreskin fibroblast
- HXGPRT, hypoxanthine-xanthine-guanine phosphoribosyltransferase
- IAA, indole-3-acetic acid
- LEM, Ligand Effector Module
- Lem1
- NBD, nitrobenzoxadiazole
- NBD-lipid
- P4-ATPase1
- PBS, phosphate-buffered saline
- Phosphatidylserine
- Phospholipid flipping
- PtdCho, phosphatidylcholine
- PtdEtn, phosphatidylethanolamine
- PtdSer, phosphatidylserine
- PtdThr, phosphatidylthreonine
- UTR, untranslated region
- cGMP, cyclic Guanosine Monophosphate
- mAID, (mini) auxin-inducible degron
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Affiliation(s)
- Kai Chen
- Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Xiyu Huang
- Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Ute Distler
- Institute of Immunology, University Medical Center of the Johannes-Gutenberg University, Mainz, Germany
| | - Stefan Tenzer
- Institute of Immunology, University Medical Center of the Johannes-Gutenberg University, Mainz, Germany
| | - Özlem Günay-Esiyok
- Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Nishith Gupta
- Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
- Intracellular Parasite Education and Research Labs (iPEARL), Department of Biological Sciences, Birla Institute of Technology and Science, Pilani (BITS-P), Hyderabad, India
- Corresponding author at: Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany.
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Vo KC, Ruga L, Psathaki OE, Franzkoch R, Distler U, Tenzer S, Hensel M, Hegemann P, Gupta N. Plasticity and therapeutic potential of cAMP and cGMP-specific phosphodiesterases in Toxoplasma gondii. Comput Struct Biotechnol J 2022; 20:5775-5789. [PMID: 36382189 PMCID: PMC9619220 DOI: 10.1016/j.csbj.2022.09.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 09/13/2022] [Accepted: 09/14/2022] [Indexed: 11/03/2022] Open
Abstract
Toxoplasma gondii is a common zoonotic protozoan pathogen adapted to intracellular parasitism in many host cells of diverse organisms. Our previous work has identified 18 cyclic nucleotide phosphodiesterase (PDE) proteins encoded by the parasite genome, of which 11 are expressed during the lytic cycle of its acutely-infectious tachyzoite stage in human cells. Here, we show that ten of these enzymes are promiscuous dual-specific phosphodiesterases, hydrolyzing cAMP and cGMP. TgPDE1 and TgPDE9, with a Km of 18 μM and 31 μM, respectively, are primed to hydrolyze cGMP, whereas TgPDE2 is highly specific to cAMP (Km, 14 μM). Immuno-electron microscopy revealed various subcellular distributions of TgPDE1, 2, and 9, including in the inner membrane complex, apical pole, plasma membrane, cytosol, dense granule, and rhoptry, indicating spatial control of signaling within tachyzoites. Notably, despite shared apical location and dual-catalysis, TgPDE8 and TgPDE9 are fully dispensable for the lytic cycle and show no functional redundancy. In contrast, TgPDE1 and TgPDE2 are individually required for optimal growth, and their collective loss is lethal to the parasite. In vitro phenotyping of these mutants revealed the roles of TgPDE1 and TgPDE2 in proliferation, gliding motility, invasion and egress of tachyzoites. Moreover, our enzyme inhibition assays in conjunction with chemogenetic phenotyping underpin TgPDE1 as a target of commonly-used PDE inhibitors, BIPPO and zaprinast. Finally, we identified a retinue of TgPDE1 and TgPDE2-interacting kinases and phosphatases, possibly regulating the enzymatic activity. In conclusion, our datasets on the catalytic function, physiological relevance, subcellular localization and drug inhibition of key phosphodiesterases highlight the previously-unanticipated plasticity and therapeutic potential of cyclic nucleotide signaling in T. gondii.
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Key Words
- 3′IT, 3′-insertional tagging
- Apicomplexa
- COS, crossover sequence
- CRISPR, clustered regularly interspaced short palindromic repeats
- DHFR-TS, dihydrofolate reductase – thymidylate synthase
- HFF, human foreskin fibroblast
- HXGPRT, hypoxanthine-xanthine-guanine phosphoribosyl transferase
- IMC, inner membrane complex
- Lytic cycle
- MoI, multiplicity of infection
- PDE, phosphodiesterase
- PKA, protein kinase A
- PKG, protein kinase G
- PM, plasma membrane
- Phosphodiesterase
- S. C., selection cassette
- TEM, transmission electron microscopy
- Tachyzoite
- cAMP & cGMP signaling
- sgRNA, single guide RNA
- smHA, spaghetti monster-HA
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Affiliation(s)
- Kim Chi Vo
- Department of Molecular Parasitology, Institute of Biology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Liberta Ruga
- Department of Molecular Parasitology, Institute of Biology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Olympia Ekaterini Psathaki
- University of Osnabrück, Center of Cellular Nanoanalytics (CellNanOs), Integrated Bioimaging Faciltiy (iBiOs), Germany
| | - Rico Franzkoch
- University of Osnabrück, Center of Cellular Nanoanalytics (CellNanOs), Integrated Bioimaging Faciltiy (iBiOs), Germany
| | - Ute Distler
- Institute of Immunology, University Medical Center of the Johannes-Gutenberg University Mainz, Mainz, Germany
| | - Stefan Tenzer
- Institute of Immunology, University Medical Center of the Johannes-Gutenberg University Mainz, Mainz, Germany
| | - Michael Hensel
- University of Osnabrück, Center of Cellular Nanoanalytics (CellNanOs), Integrated Bioimaging Faciltiy (iBiOs), Germany
| | - Peter Hegemann
- Department of Molecular Parasitology, Institute of Biology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Nishith Gupta
- Department of Molecular Parasitology, Institute of Biology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
- Department of Biological Sciences, Birla Institute of Technology and Science, Pilani (BITS-P), Hyderabad, India
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