Previously Unknown Organelle Discovered in Human Cells

A team led by researchers at the University of Virginia School of Medicine has identified a previously unknown organelle within human cells, which they have named the hemifusome. This specialized structure plays a significant role in helping cells sort, recycle, and discard important materials. According to the scientists, understanding the hemifusome may provide new insights into genetic disorders that affect these essential cellular processes.

Seham Ebrahim, co-author of the study published in Nature Communications, described the discovery as “like discovering a new recycling center inside the cell. We think the hemifusome helps manage how cells package and process material, and when this goes wrong, it may contribute to diseases that affect many systems in the body.”

One such disease is Hermansky-Pudlak syndrome, a rare genetic disorder associated with albinism, vision problems, lung disease, and blood clotting issues, all of which are linked to cellular cargo handling defects.

The research team utilized cryo-electron tomography (cryo-ET) to visualize the hemifusome. This imaging technique allowed them to capture detailed images of the organelle. Their findings suggest that hemifusomes assist in forming vesicles—tiny sacs that transport materials within the cell. Ebrahim explained, “You can think of vesicles like little delivery trucks inside the cell. The hemifusome is like a loading dock where they connect and transfer cargo. It’s a step in the process we didn’t know existed.”

Although hemifusomes have gone undetected until now, the researchers found them to be common in certain cell areas. “This is just the beginning,” Ebrahim said. “Now that we know hemifusomes exist, we can start asking how they behave in healthy cells and what happens when things go wrong. That could lead us to new strategies for treating complex genetic diseases.”