Researchers from Penn State University and the University of California have discovered how a protein is crucial for the growth of healthy cells in mammals. This is according to a study published in the journal Proceedings of the National Academy of Sciences.
In previous research, Aimin Liu, associate professor of biology at Penn State University and co-author of the study, and his colleagues discovered that a protein called C2 calcium-dependent domain containing 3 (C2cd3) is needed in order for cilia to grow on the surfaces of cells.
Cilia are hair-like structures that reside on the surface of mammalian cells. They are responsible for transmitting and processing information in the body.
"You could think of cilia as the cells' antennae. Without cilia, the cells can't sense what's going on around them, and they can't communicate," says Liu.
Furthermore, cilia also play an important role in filtering bacteria, preventing it from entering the body's organs.
Lack of cilia may lead to serious health conditions, including polycystic kidney disease, blindness and neurological disorders. Therefore, the researchers say their findings have important implications for human health.
How C2cd3 works
Liu and colleagues first discovered that C2cd3 was important for cilium formation in 1962. They discovered that mice lacking the protein demonstrated serious developmental problems.
However, the researchers did not understand why lack of C2cd3 led to these developmental problems. Now, this new research has answered their question.
Hair-like structures called cilia are pictured on a mouse embryo, which are crucial for healthy cell growth. Researchers say without a protein called C2cd3, cilia are unable to grow.
Image credit: Aimin Liu Lab, Penn State University
The investigators knew that a cilium grows from a centriole - a structure that attaches itself to the inner surface of the cell and acts as an anchor for the cilium.
A cell needs to amass a set of appendages at one end of the centriole prior to growing a cilium. This allows the appendages to attach the centriole to the surface of the cell, meaning the cilium can then grow.
However, the researchers did not know how the appendages are assembled.
This new research revealed that when there is no C2cd3 protein present, the appendages are not assembled at the end of the centriole. This means the centriole is not linked to the cell membrane and is unable to take on other proteins that allow the cilium to grow.
"So our protein is required for the very first step of putting a cilium together," explains Liu. "Without those appendages, the cilium growth cannot happen."
Potential treatments for ciliopathies
The investigators say they hope their findings will open doors to better knowledge surrounding cilium development, as well as better treatments for diseases related to lack of cilia - known as ciliopathies.
Abnormal function of cilia can lead to numerous diseases. It plays a part in cystic disorders of the kidney and liver, and can even lead to blindness or deafness.
Commenting on the findings, Liu says:
"If we want to better understand and treat diseases related to cilium development, we need to identify important regulators of cilium growth and learn how those regulators function.
This work gives us significant insight into one of the earliest steps in cilium formation."
In other news, Medical News Today recently reported on a study detailing the discovery of a protein that destroys migrating cancer cells on contact.