Nutrient Uptake and Metabolism - Project A1

Conserved and lineage-specific functions of Plasmodium membrane transport proteins

Host lab:  KAI MATUSCHEWSKI (Humboldt University, Berlin) 

Partner lab:  ALEX MAIER (Research School of Biology, ANU, Canberra)

Background: An intracellular life style and population expansion strictly depends on efficient uptake of ions, nutrients, building blocks and membrane lipids. Mammalian Plasmodium parasites have very tight host species barriers and co-evolved with their respective hosts. Work in two Plasmodium parasite models, the murine malaria model P. berghei and P. falciparum blood cultures, combines phenotyping of the entire parasite life cycle and parasite/host cross-talk during infection with in-depth analysis of blood infection by the human human pathogen. These studies are expected to uncover druggable targets and generate virulence attenuated parasite lines for preclinical testing of malaria vaccine strategies.

Scope/Central question: To what extend transport proteins of human and murine malaria parasites have adapted to their cognate hosts or whether they confer identical functions remains unsolved. Distinct parasite traits, such as gametocytogenesis, differ profoundly between species and might be partly attributed to tailored membrane transport proteins.

Methods employed: We will employ experimental genetics in P. falciparum and P. berghei, including targeted gene deletion by classical homologous recombination and CRISPR/CAS9 mutagenesis, promoter swap, and cross-species complementation to analyze the cellular roles of selected candidates. They include phospholipid transporters, flippases, and metabolite porters. Functional complementation of vital genes will uncover whether candidate transporters are tailored to distinct physiological conditions or broadly active.

3-year plan:

Year 1. Prioritizing candidate transporters by reverse genetics, endogenous fluorescent tagging, and phenotyping of mutant parasites in Plasmodium berghei (Berlin).

Year 2. Generation of Plasmodium falciparum knockouts and conditional knockouts. Phenotyping and downstream analysis of parasite strains (Canberra)

Year 3. Functional characterization and cross-species complementation of selected transporters to uncover their roles in parasite stage conversion and parasite/host interactions (Berlin).

Keywords: Plasmodium, malaria, transporter, virulence attenuation

Keywords (methods): experimental genetics, CRISPR/Cas9, endogenous tagging, fluorescent microscopy, cell culture, Anopheles mosquito work

References:

1.      Matz J.M., Watanabe M., Falade M, Tohge T, Hoefgen R., Matuschewski K. (2019) Plasmodium para-aminobenzoate synthesis and salvage resolve avoidance of folate competition and adaptation to host diet. Cell Rep. 26: 356-363.

2.      Kenthirapalan S., Waters A.P., Matuschewski, K., Kooij, T.W.A. (2016) Functional profiles of orphan membrane transporters in the life cycle of the malaria parasite. Nat. Commun. 7:10519.