Figure 2.

Schematic representation of Ca²⁺ transport pathways within a model trypanosomatid parasite based on data published previously. Ca²⁺ is indicated as blue circles. Ca²⁺ upon entering the cell through a Ca²⁺ channel can be sequestered into the ER by the action of SERCA, into the mitochondrion by the action of MCU complex or into the acidocalcisomes by the action of a PMCA. Ca²⁺ release from the mitochondrion is through a Ca²⁺/H⁺ exchanger (CHX) that could be LETM1. Ca²⁺ from acidocalcisomes is released when IP₃ stimulates the IP₃R located in this organelle. A presenilin can be a leak channel in the ER. Ca²⁺ release through the parasite plasma membrane is achieved by a PMCA. PMCA, plasma membrane Ca²⁺-ATPase; Ca_v Voltage gated Ca²⁺ channel; IP₃, inositol 1,4,5-trisphosphate; IP₃R, IP₃ receptor; GDT1, GCR1 dependent translation factor; MCU complex, mitochondrial calcium uniporter complex; VDAC, voltage-dependent anion-selective channel; Letm1 (LETM), leucine zipper-EF-hand containing transmembrane protein 1; CHX, Ca²⁺/H⁺ exchanger; PSEN presenilin; SERCA, sarcoplasmic-endoplasmic reticulum Ca²⁺-ATPase; ER, endoplasmic reticulum; OMM, outer mitochondrial membrane; IMM, inner mitochondrial membrane.