Malaria parasites use a soluble RhopH complex for erythrocyte invasion and an integral form for nutrient uptake
Marc A Schureck,
Joseph E Darling,
Alan Merk,
Jinfeng Shao,
Geervani Daggupati,
Prakash Srinivasan,
Paul Dominic B Olinares,
Michael P Rout,
Brian T Chait,
Kurt Wollenberg,
Sriram Subramaniam,
Sanjay A Desai
Affiliations
Marc A Schureck
Laboratory of Malaria and Vector Research, NIAID, National Institutes of Health, Rockville, United States
Joseph E Darling
Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, United States
Alan Merk
Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, United States
Jinfeng Shao
Laboratory of Malaria and Vector Research, NIAID, National Institutes of Health, Rockville, United States
Geervani Daggupati
Department of Molecular Microbiology and Immunology, and Johns Hopkins Malaria Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, United States
Prakash Srinivasan
Department of Molecular Microbiology and Immunology, and Johns Hopkins Malaria Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, United States
Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, United States
Michael P Rout
Laboratory of Cellular and Structural Biology, The Rockefeller University, New York, United States
Brian T Chait
Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, United States
Kurt Wollenberg
Office of Cyber Infrastructure & Computational Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, United States
Malaria parasites use the RhopH complex for erythrocyte invasion and channel-mediated nutrient uptake. As the member proteins are unique to Plasmodium spp., how they interact and traffic through subcellular sites to serve these essential functions is unknown. We show that RhopH is synthesized as a soluble complex of CLAG3, RhopH2, and RhopH3 with 1:1:1 stoichiometry. After transfer to a new host cell, the complex crosses a vacuolar membrane surrounding the intracellular parasite and becomes integral to the erythrocyte membrane through a PTEX translocon-dependent process. We present a 2.9 Å single-particle cryo-electron microscopy structure of the trafficking complex, revealing that CLAG3 interacts with the other subunits over large surface areas. This soluble complex is tightly assembled with extensive disulfide bonding and predicted transmembrane helices shielded. We propose a large protein complex stabilized for trafficking but poised for host membrane insertion through large-scale rearrangements, paralleling smaller two-state pore-forming proteins in other organisms.
