Functional characterisation of Ago2 as erythrocyte host protein that is translocated to the Plasmodium parasite.

• Applicant: Dr. Franziska Hentzschel
• Subject Area: Parasitology and Biology of Tropical Infectious Disease Pathogens
• Term: from 2018 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 404044656

Malaria, caused by eukaryotic unicellular Plasmodium parasites infecting erythrocytes, is one of the deadliest human infectious diseases. Most antimalarial drugs available target parasite proteins which can rapidly mutate, rendering parasites resistent. Given the rapidly increasing spread of such resistances to conventional anti-malarial drugs, it is now of utmost importance to identify novel drug targets, in particular essential host proteins which are less prone to resistance mutations. One candidate target is the host protein Argonaute 2 (Ago2), which is expressed in erythrocytes. Intriguingly, recent studies have found that Ago2 translocates into rodent and human Plasmodium blood stages, and that the artificial overexpression of Ago2 in rodent Plasmodium specifically affects mRNA storage in female gametocytes. These observations give rise to my hypothesis that Ago2 fulfills yet unknown but potentially essential functions in the parasite. The aim of this proposal is the comprehensive dissection of the role of Ago2 in the blood stage biology of Plasmodium. I will study both human and rodent malaria parasites with the following three specific aims: (1) Determination of the precise subcellular localisation of Ago2 using super resolution microscopy and electron microscopy. (2) Phenotyping Plasmodium in Ago2-deficient erythrocytes, which I will generate either by inhibition of Ago2 using chemical agents, or by depletion of Ago2 protein in genetically engineered erythrocytes. (3) Functional characterisation of Ago2 RNA and protein interaction partners that will be identified by immunoprecipitation of Ago2 followed by RNA sequencing and mass spectrometry. In summary, this project will for the first time elucidate the function of a host protein that is translocated into the Plasmodium blood stage. This research will not only provide valuable insight into a potential target for host-directed therapy of Plasmodium, but I will also acquire novel scientific skills that will foster my future academic career.

• DFG Programme: Research Fellowships
• International Connection: United Kingdom
• Host: Professor Dr. Matthias Marti