Researchers at Utrecht University have discovered how cells transport essential molecules such as proteins and peptides into their interior, for communication purposes and as a source of energy. Team leader, Dr. Bert Janssen explains how this insight is important to develop new drugs to combat a variety of diseases. On November 22, 2017, the team’s discovery was published in the renowned journal Nature Communications.
The cellular postal system
Our cells are intricate factories that need to maintain a careful internal and external balance to stay healthy. To protect itself from outside influences, the cell is surrounded by an impenetrable barrier, the membrane. To allow specific cargo that the cell needs to pass though, cells have an intricate postal system that can pick up proteins and nutrients outside, carry them across the membrane and deliver them inside (via a process called endocytosis).
Sortilin is a protein that has an important task in deciding which molecules can come in and which need to stay out. Like an antenna, sortilin sticks through the cell membrane and senses the world outside the cell. It can grab onto molecules the cell needs and transport these into the cell. Once it’s delivered its cargo inside, it returns to the cell membrane for another round of mail service.
When sortilin function is impaired, this can lead to heart disease, neurological disorders and metabolic disease. Researchers are eager to figure out how sortilin works, so that they can develop new drugs that can fix the problem. Until now, it was not known how this postmaster was able to carry so many different molecules into the cell without accidentally bringing in ‘bad’ ones, and how it released the molecules inside the cell.