(Not) helping Plasmodium break in

Abstract

An integral step in the establishment of malarial infection is invasion of the host erythrocyte by the parasite. Previous work had reported that presenilin-like signal peptide peptidase (SPP) has a role during invasion by Plasmodium falciparum, targeting the cytoskeletal protein Band 3 on the erythrocyte surface; this, surprisingly, implied that, although SPP is an ER protein, it is secreted during invasion. However, a separate study found that SPP has a role in growth, not invasion, of Plasmodium berghei. Here, Marapana et al. sought to resolve the precise contribution of SPP during the establishment of infection. Using fluorescence imaging, they found that SPP resides in the ER and does not relocalize to the parasite cell surface during invasion. Importantly, blocking SPP with a range of inhibitors had no effect on invasion; however, it did interfere with parasite development, which suggests that the protein could be targeted for therapeutic purposes.