Malaria parasites survive in human erythrocytes by importing and digesting hemoglobin within a specialized organelle, the digestive vacuole (DV). Although chloroquine and other antimalarials act within the DV, the routes used by drugs, ions, and amino acids to cross the DV membrane remain poorly understood. Here, Saggu et al. used single DV patch-clamp to identify a novel large conductance anion channel as the primary conductive pathway on this organelle in Plasmodium falciparum, the most virulent human pathogen. This Big Vacuolar Anion Channel (BVAC) is primarily open at the DV resting membrane potential and undergoes complex voltage-dependent gating. Conductance and gating are unaffected by antimalarials targeting essential DV activities and are conserved on parasites with divergent drug susceptibility profiles, implicating an unexploited antimalarial target. Direct transport measurements at the DV membrane provide foundational insights into vacuolar physiology, should help clarify antimalarial action and drug resistance, and will guide therapy development against the parasite’s metabolic powerhouse. The image shows transmission electron micrographs of infected erythrocytes, colorized to the highlight the digestive vacuole.

Image Credit: Austin Athman