Researchers at the University of Alberta in Canada have made a discovery which could completely change science's understanding of one of the cell's most basic processes.
The researchers have discovered a fifth protein complex known as an adaptins, which has existed for billions of years, but no one else had found.
The findings could shed new light on the origin of some the most threatening and mysterious neurological diseases, including Alzheimer's and Huntington's disease.
"What this does for cell biology is open up a whole new avenue of research," said Joel Dacks, cell biologist at the Department of Cell biology in the U of A Faculty of Medicine & Dentistry, who co-authored the paper.
"We thought there were four big players in the processes of how things got moved around in the back half of the cell. There's a fifth player on the field; we just couldn't see it."
It has been well known for a while that there are four major protein complexes, often referred to as pathways, which move material in, out and around the cell. When those pathways break down, the result is often neurodegenerative diseases.
This new fifth pathway is present in cells in humans, plants, and single-celled amoebas, meaning it is likely to have evolved billions of years ago. It also could hold some important clues as to how cells have evolved over time.
"What we did, was found a fifth one that nobody expected would be there," said Dacks. "It's like finding an extra island in the Pacific Ocean."
The discovery was made whilst studying a harmless soil amoeba for evolutionary purposes.
The research is published in Public Library of Science Biology.