NEW YORK / RankWire.AI / – Scientists have captured the molecular machinery that malaria parasites use to enter human red blood cells. The finding overturns a decades-old view of the moving junction as a passive ring. Researchers found that the structure acts as an active machine that grips and reshapes the cell membrane during invasion. The study appeared in the scientific journal Cell and focused on Plasmodium falciparum, the parasite responsible for the deadliest form of malaria.
Researchers at Columbia University isolated the moving junction while parasites were entering red blood cells. The structure exists for less than 60 seconds, making it difficult to study with conventional methods. The team chemically stopped the invasion process at a critical moment and removed the protein complex intact. Scientists then used cryogenic electron microscopy to map its three-dimensional structure at high resolution and examine how its components interact with the host cell.
The moving junction contains proteins known as AMA1 and RON, which connect the parasite to the red blood cell. Earlier models described the junction mainly as an anchor or doorway. The new images showed charged protein sections that attach to the cell membrane. They also revealed wedge-shaped helices that press into the membrane, reduce its thickness and help bend it around the invading parasite.
Moving junction actively reshapes host cells
The findings show that malaria parasites do more than pull themselves through a fixed opening. Their protein machinery changes the physical structure of the red blood cell membrane during entry. This remodeling helps the membrane wrap tightly around the parasite as it moves inside. Once invasion ends, the parasite occupies a protected compartment where it grows, reproduces and prepares to infect additional blood cells.
The Columbia University team also used the structural map to design a small experimental protein called A2. The molecule binds to a key region of AMA1 and prevents it from connecting with RON2. Laboratory tests found that A2 disrupted formation of the moving junction and blocked parasite invasion of red blood cells. The work demonstrated that researchers can target a specific weakness identified through the new structural model.
Detailed structure identifies an invasion target
The experimental molecule is not an approved medicine, and the study did not include human clinical trials. Its role was to test whether the newly mapped interaction could serve as a precise biological target. The researchers found that blocking the AMA1 and RON2 connection stopped the parasite before it entered the blood cell. The moving junction also operates across several parasite species and stages, which makes its structure important for broader malaria research.
Malaria caused an estimated 282 million cases and 610,000 deaths worldwide in 2024, according to the World Health Organization. The WHO African Region recorded about 95% of those deaths, with children under five carrying the heaviest burden. The new study explains a central step in the infection cycle that drives malaria symptoms and transmission. It also gives scientists a detailed model for studying how malaria parasites penetrate human cells and how that process can be interrupted.