A prokaryotic-like cardiolipin synthase is essential to maintain mitochondrial function, lipid homeostasis, and survival of the blood stage malaria parasite Plasmodium falciparum.

Mitochondrion is essential for the propagation of the malaria parasites in the human host. The structure, biogenesis, and function of mitochondria depend on the synthesis of a key mitochondrial membrane-specific phospholipid, cardiolipin (CL), which is typically synthesized by cardiolipin synthase (CLS). Unlike most eukaryotic cell models, the synthesis of CL in the malaria parasite remains unresolved. Here, we show that Plasmodium falciparum harbors a prokaryotic-like CLS (PfCLS), which is functional in the parasite mitochondrion. Inducible knockdown of PfCLS disrupts parasite development and kills the parasites. Ablation of PfCLS and a reduction in levels of CL affect the assembly of mitochondrial respiratory super-complexes. In addition, PfCLS-iKD parasites exhibited hypersensitivity to antimalarial drugs targeting the mETC, such as Atovaquone. Lipidomic analyses revealed loss of CL content and widespread perturbations in phospholipid homeostasis in the parasites. Quantitative metabolomics shows disruption of the TCA cycle and amino acid levels. Overall, these results ascertain that PfCLS is essential for asexual blood stages of the parasite, playing a critical role at the juncture of mitochondrial membrane biogenesis, mitochondrial function, and phospholipid synthesis/homeostasis in the parasite.