Tau proteins carry out very important functions in the brain. Especially in brain cells or neurons. They are akin to spot welds on cellular scaffolds that form tracks that shuttle other vital molecules to and fro within nerve cells. Their activity is governed by other cellular communicators called "phosphate groups." They attach to the tau proteins and enable them to perform their unique task. However, under certain circumstances the assembly line that regulates where and how many phosphate groups are attached runs amok. Under these conditions more and more phosphate groups are attached end to end, and instead of enhancing the activity of tau proteins, they create problems.

One type of problem with these "hyper-phosphorylated" tau proteins is that they accumulate and form masses called neuro-fibrillary tangles (NFTs). These NFTs are a purported cause of Alzheimer disease.

Based on these observations, findings made by researchers at McGill University in Canada offer new hope for the early diagnosis and treatment of Alzheimer disease. In a study published in the Journal of Biological Chemistry on May 15, they reported that the addition of a single phosphate group to a specific amino acid (protein building block) in tau proteins is a principal cause of Alzheimer disease.

Normal tau proteins only contain three or four phosphate groups, but the abnormal tau proteins can contain 20 to 25 additional phosphates. What the McGill scientists discovered was that the addition of a single phosphate group to a certain amino group (Serine 202) was the primary culprit responsible for the changes seen in Alzheimer disease.

This is important for two reasons. The first is that brain scans could be developed to identify that change. The second is that the enzyme that adds the phosphate to that specific amino group could become the target for drug therapy. Together, these suggest that early diagnosis and treatment may be at hand!