Poster Presentation Lorne Infection and Immunity 2023

Characterisation of an essential dynamin-like protein in the malaria parasite Plasmodium falciparum (#165)

Emma McHugh 1 , Katie Fitzsimmons 1 , Richard Marais 1 , Stuart A Ralph 1
  1. University of Melbourne, Parkville, VIC, Australia

Feeding of Plasmodium falciparum on host red blood cell cytoplasm generates haemoglobin breakdown products required for activation of the antimalarial artemisinin. Resistance to artemisinin is mediated by mutations in the PfKelch13 protein, which is located at the constriction of the cytostome, the invagination through which host cytoplasm is uptaken into the parasite. Mutations in PfKelch13 decrease cytostomal haemoglobin uptake and result in decreased activation of artemisinin. In Toxoplasma gondii, an orthologue of PfKelch13 was shown to co-immunoprecipitate with a dynamin-like protein known as TgDrpC. Dynamin-like proteins are involved in membrane constriction processes such as endocytosis and vesicle budding, and we therefore hypothesise that the orthologous P. falciparum dynamin-like protein PfDYN3 (PF3D7_1218500) is involved in cytostomal feeding of P. falciparum. In order to investigate PfDYN3, we used CRISPR to introduce an epitope tag and loxP sites that enable inducible disruption of the gene. Disruption of PfDYN3 results in parasite death in the subsequent asexual cycle. Super-resolution fluorescence microscopy reveals that in early-stage trophozoites, PfDYN3 is located in approximately three or four discrete puncta at the parasite periphery. Additionally, we have performed mass spectrometry on cross-linked PfDYN3 co-immunoprecipitation eluates to elucidate interacting proteins.