DTC

DTC (PF3D7_0823900) is a carboxylic acid carrier of the P. falciparum mitochondrion that supplies carbon to the parasite's branched TCA metabolism (PMID:21986531, PMID:40398604). In vitro reconstitution of cell-free-synthesized protein into proteoliposomes established its transport activity as oxoglutarate-malate, oxoglutarate-oxaloacetate, and oxoglutarate-oxoglutarate exchange, consistent with an oxoglutarate-malate antiporter operating across the inner mitochondrial membrane (PMID:21986531). In vivo, isotopic tracing in parasites lacking DTC together with YHM2, PfMPC1, and PfMPC2 shows a marked loss of glutamine-derived label in TCA cycle metabolites, placing DTC—acting alongside YHM2—in the route that imports glutamine-derived carbon into the mitochondrion (PMID:40398604). Despite this metabolic contribution, genetic knockout of DTC only mildly affects asexual blood-stage replication, even in a quadruple-carrier-deficient background, indicating it is dispensable for growth under standard conditions owing to redundant carboxylic acid transport routes (PMID:40398604). Beyond these transport and metabolic-flux findings, no further mechanistic detail—including structural basis, regulation, or stage-specific roles—has been characterized in the available corpus.

1. 2011 High

   Establishing what substrates DTC transports was needed to assign it a biochemical function; reconstitution showed it is an oxoglutarate exchanger, implicating it in mitochondrial carboxylic acid trafficking.

   Evidence Cell-free translation, proteoliposome reconstitution, and substrate-specificity transport assays in P. falciparum

   PMID:21986531

   Open questions at the time

   • No independent replication of the reconstituted activity
   • In vitro liposome directionality does not confirm the physiological direction of exchange in the mitochondrion
   • No structural model or residue-level mechanism of substrate selection
2. 2025 Medium

   Whether DTC is required for blood-stage survival was unknown; genetic knockout demonstrated it is dispensable even when combined with loss of other carriers, revealing functional redundancy among carboxylic acid transporters.

   Evidence Genetic knockout (including a quadruple KO with PfMPC1/2 and YHM2) and parasite growth assays in P. falciparum

   PMID:40398604

   Open questions at the time

   • Redundant transporters accounting for dispensability are not individually mapped
   • Phenotype tested only under standard blood-stage conditions
   • Single lab; no orthogonal confirmation of the null phenotype
3. 2025 Medium

   The in vivo metabolic role of DTC was undefined; isotopic tracing in carrier-deficient parasites showed loss of glutamine-derived carbon in TCA metabolites, placing DTC in the mitochondrial import of glutamine derivatives.

   Evidence Genetic knockout combined with isotopic metabolite tracing (HPLC-MS metabolomics) in P. falciparum

   PMID:40398604

   Open questions at the time

   • Attribution to DTC specifically is confounded by simultaneous YHM2 deletion
   • The precise glutamine-derived metabolite transported by DTC is not resolved
   • Contribution of DTC relative to YHM2 to the observed flux change is not separated

• How DTC's individual transport contribution is distinguished from redundant carriers, and its structural and regulatory basis, remains unresolved.
• No single-gene metabolic phenotype isolating DTC from YHM2
• No structural characterization of the transporter
• No data on stage-specificity beyond asexual blood stage