Investigation of the endocytic and recycling process of the apicomplexan parasite Toxoplasma gondii

• Applicant: Dr. Simon Gras
• Subject Area: Parasitology and Biology of Tropical Infectious Disease Pathogens
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 464878930

Apicomplexan parasites establish a retrograde membrane flow that is involved in force generation during gliding motility and host cell invasion. This flow is generated by the coordinated action of the parasite’s acto-myosin system and a secretory-endocytic cycle. In a recent study, I highlighted the link between gliding motility, retrograde membrane flow, secretion and endocytosis, which led to a new model for apicomplexan motility, the so-called Fountain Flow Model (Gras et al., PLoS Biology 2019). Our knowledge regarding endocytic uptake mechanisms is still in its infancy. In my recent work, I demonstrated efficient uptake of exogenous material by extracellular parasites, but the identity of the molecular machinery required for endocytic uptake is unknown. To close major gaps in the knowledge regarding the substrates, mechanisms and regulation of endocytosis in apicomplexans, for extracellular and intracellular parasites, I will focus here on:1. Identification of endocytosed and recycled surface proteins 2. Identification and characterisation of the mechanisms involved in endocytosis and evaluation of its involvement in motility3. Analysis of plasma membrane endocytosis/recycling during intracellular stages. 4. Exploiting the endocytic machinery for novel intervention strategies

• DFG Programme: Research Grants
• International Connection: United Kingdom
• Cooperation Partners: Dr. Paula MacGregor; Professor Dr. Ross Waller, Ph.D.