Pagura, L.; Todd-Nelson, J.; Merlet, C.; Hanna, J. C.; Faulds, L.; Chandrasekaran, S.; Park, S. C.; Koehler, K.; Sanchez-Rosario, Y.; Johnson, M. D.; Bissardon, C.; Cloetens, P.; Bowler, M. W.; Fairweather, S. J.; van Dooren, G. G.; Koshy, A. A.; Harding, C. R.

Copper is a conserved cofactor, required for aerobic mitochondrial respiration and other cellular processes. Pathogens acquire copper from their hosts, however the mechanisms of uptake and role of copper within divergent eukaryotes is not well understood. Here, using genetic and metabolic approaches we identify and validate the two copper transporters of Toxoplasma gondii, and we determine the role of copper in metabolism and pathogenesis. We show that Ctr1 is the major copper importer, and its deletion leads to a loss of parasite-associated copper, a significant growth defect and inhibition of mitochondrial complex IV, required for respiration. However, these parasites are viable, having undergone a significant metabolic shift away from mitochondrial respiration. Absence of Crt1 can be fully and rapidly rescued by exogenous copper, which we believe is transported through the lower-affinity transporter Ctr2. Ctr2 is dispensable in rapid growth, however, has a role in parasite persistence in chronic infection, both in vitro and in vivo. Together, these findings reveal for the first time a critical role for copper uptake in shaping metabolic plasticity and highlight the importance of nutrient availability in regulating apicomplexan metabolism.