A tau protein is a protein found in neurons, primarily in the central nervous system. Several different versions or isoforms of tau protein can be found in the body, and all are critical to the healthy functioning of a normal nervous system. These proteins were first identified in the 1970s, and research on tau protein is continuing in many areas of the world, as researchers are curious about the role of these proteins in healthy individuals and in certain diseases which involve the central nervous system.
In a healthy person, tau protein interacts with a compound called tubulin to strengthen the neural tubes in the axons of neurons. The neural tubes essentially act like train tracks for signals to pass along the axon. Disruption in the level of tau protein can lead to instability in the neural tubes, which makes it difficult for neurons to pass signals along. This in turn can lead to neurological problems as the functioning of the central nervous system is interrupted, and depending on the area of the interruption, a patient can experience various symptoms.
In a collection of conditions known as tauopathies, the tau protein changes chemically, becoming entangled in the neural tubes and blocking signals as the walls of the neural tubes collapse. One of the most infamous examples of a tauopathy is Alzheimer's disease, a very serious degenerative brain disease which strikes elderly people. Other tauopathies include: Pick's disease, corticobasal degeneration, frontotemporal dementia, and supranuclear palsy. Understanding the role of tau protein in these diseases may be an important part of treating and preventing them, as researchers learn how and why tau protein occasionally goes awry, and how it might be corrected.
When tau proteins become chemically altered, the alteration changes the way in which they fold. Alterations in protein folding, even they are subtle, can change the fundamental function of the protein. Researchers have identified the normal structure of several tau proteins, and they have found examples of improperly folded proteins associated with various neurological pathologies.
As with many other components of the central nervous system, tau proteins are imperfectly understood, although researchers are learning more about them all the time. The central nervous system is an incredibly complex and rather astounding feat of biology, and learning about all of its components and how they interact can contribute a great deal of knowledge to everything from degenerative neurological conditions to human psychology.