The malaria parasite, Plasmodium, invades red blood cells by creating a temporary molecular portal that closes behind it. That entry mechanism, critical to the parasite's blood-stage cycle, has now been captured with enough structural detail to follow its formation and disappearance step by step.

Red blood cell invasion is one of the most critical phases of the Plasmodium life cycle and one reason malaria remains so difficult to fight. Understanding exactly how the parasite crosses the red blood cell membrane has long been a goal of molecular parasitology, both for the basic interest of the process and for its value as a therapeutic target.

Thanks to new structural imaging capabilities, researchers have captured the portal in action, observing how it assembles just before entry and disassembles afterwards. The result is a direct view of a process that until now could only be inferred from indirect data.

The finding opens the door to strategies that block the formation of this portal and, with it, red blood cell invasion at one of its most vulnerable stages.