ATP2, The essential P4-ATPase of malaria parasites, catalyzes lipid-stimulated ATP hydrolysis in complex with a Cdc50 β-subunit

ABSTRACT

Gene targeting approaches have demonstrated the essential role for the malaria parasite of membrane transport proteins involved in lipid transport and in the maintenance of membrane lipid asymmetry, representing emerging oportunites for therapeutical intervention. This is the case of ATP2, a Plasmodium-encoded 4 P-type ATPase (P4-ATPase or lipid flippase), whose activity is completely irreplaceable during the asexual stages of the parasite. Moreover, a recent chemogenomic study has situated ATP2 as the possible target of two antimalarial drug candidates. In eukaryotes, P4-ATPases assure the asymmetric phospholipid distribution in membranes by translocating phospholipids from the outer to the inner leaflet. In this work, we have used a recombinantly-produced P. chabaudi ATP2 (PcATP2), to gain insights into the function and structural organization of this essential transporter. Our work demonstrates that PcATP2 associates with two of the three Plasmodium-encoded Cdc50 proteins: PcCdc50B and PcCdc50A. Purified PcATP2/PcCdc50B complex displays ATPase activity in the presence of either phosphatidylserine or phosphatidylethanolamine. In addition, this activity is upregulated by phosphatidylinositol 4-phosphate. Overall, our work describes the first biochemical characterization of a Plasmodium lipid flippase, a first step towards the understanding of the essential physiological role of this transporter and towards its validation as a potential antimalarial drug target.

KEYWORDS:

• Malaria
• P4-ATPases
• lipid flippase
• PfATP2
• membrane transport proteins
• heterologous expression

Acknowlegments

We would like to thank Dr Christine Jaxel for all the support and discussions during this project, and to Dr Eugene Diatloff and Dr Jing Yuan for critically reading the manuscript. We also thank Quentin Rochette for his early work on this project. This work was supported by the ANR grants ANR-14-CE09-0022 to GL, and ANR-18-C811-0009-02 to JLVI, the French Infrastructure for Integrated Structural Biology (FRISBI; ANR-10- INSB-05), and the Centre National de la Recherche Scientifique (CNRS). In memory of Prof Ronald H. Kaback.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Agence Nationale de la Recherche [grant number ANR-14-CE09-0022,ANR-18-C811-0009-02]; French Infrastructure for Integrated Structural Biology [grant number ANR-10- INSB-05].