Presentation description

Malaria is endemic to much of the developing world and kills over 600,000 people per year. Severe malaria is caused by Plasmodium falciparum parasites that invade and replicate within the red blood cell (RBC). Like all eukaryotic cells, P. falciparum requires iron for foundational cellular processes such as mitochondrial respiration, DNA synthesis/repair, and electron transfer chemistry. Our research goal is to uncover the mechanism by which P. falciparum obtains iron for biological functions while residing in the human RBC. Recent work in our lab identified a homolog of the high-affinity divalent metal transporter 1 (DMT1) that is vital for parasites to scavenge RBC iron. However, P. falciparum DMT1 (PfDMT1) has an unusually long and disordered N-terminus that appears to be cleaved in the mature protein. Additionally, PfDMT1 contains unusual amino acid changes in the metal binding pocket relative to other DMT1 homologs that may impact its physiological function. In this study, we heterologously expressed tagged PfDMT1 in bacteria and parasites to investigate its proteolytical processing metal uptake properties. Western blot analysis of PfDMT1 expressed in parasites versus bacteria allowed us to test the molecular weight of the protein in a system that lacked native proteases present in P. falciparum. We also tested the ability of PfDMT1-expressing bacteria to take up metal ions using both colorimetric and metal-survival assays. These studies provide crucial insights into the biochemical features of PfDMT1 that expand our understanding of parasite biology and can inform the rational design of parasite-specific inhibitors as a novel therapeutic strategy.