Is Intracellular Calcium Transport Regulated by the Mitochondrial Calcium Uniporter in Crithidia fasciculata?

Mitochondrial Ca2+ contributes to vital cellular processes in protozoan parasites such as host cell invasion, bioenergetics, and cellular signaling. The mitochondrial calcium uniporter (MCU) is a gated channel that regulates calcium transport across the inner membrane of the mitochondria. In this study, I will characterize properties of a MCU in Crithidia fasciculata, a relative of the pathogens Leishmania and Trypanosoma. Because MCU subunit D in T. brucei reduces Ca2+ uptake by mitochondria, a similar pattern is expected in C. fasciculata. To assess this, the calcium uptake by permeabilized C. fasciculata cells was measured using the fluorescent dye calcium green-5N. Ruthenium red, an inhibitor of the MCU, was used to determine the contribution of the MCU to calcium uptake. By studying the mechanism of mitochondrial Ca2+ transport in C. fasciculata, future research can be conducted on the interactions between MCU and essential energy pathways.