Plug for the parasitophorous duct: a solution of two conundra

• Published in: Malaria Journal
• Main Authors: Prapon Wilairat, Saranya Auparakkitanon
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMC 2020
• Subjects: Plasmodium falciparum; Merozoite egress; Merozoite invasion; Parasitophorous duct; Parasitophorous vacuolar membrane; Plug; Arctic medicine. Tropical medicine; RC955-962; Infectious and parasitic diseases; RC109-216; Arctic
• Online Access: https://doi.org/10.1186/s12936-020-03445-9; https://doaj.org/article/59f5e5e131824b8fa9d3dd8661c2d103

Abstract Background We present two conundra in the biology of intraerythrocytic malaria parasite: how an apparent open parasitophorous duct provide direct access of only a select set of serum proteins to the parasitophorous vacuole, and how proteases mediate membrane lysis to allow merozoite egress. Solution We posit the existence of a parasitophorous vacuolar duct plug that is originally formed from a tight junction (or parts thereof) between merozoite apical surface and red blood cell plasma membrane, which by moving over the parasite surface towards the posterior end draws the parasite into the host cell interior, and by remaining at the passage orifice provides a location of transporter(s) for import of serum proteins into parasitophorous vacuole and an opening for merozoite egress upon its dissolution/dismantling through protease(s) action. Conclusion This notion obviates the need of a distinct intact parasitophorous vacuolar membrane, which in the proposed model is an extension of the red blood cell membrane but still forms an intracellular compartment for parasite growth and development. The model is testable using existing high-resolution electron and X-ray tomography tools.