Tau protein
| Tau protein | ||
|---|---|---|
|
||
| Properties of human protein | ||
| Mass / length primary structure | 352 - 757 amino acids (depending on isoform) | |
| Isoforms | 9 | |
| Identifier | ||
| Gene name | MAPT | |
| External IDs | ||
| Occurrence | ||
| Homology family | dew | |
| Parent taxon | multicellular animals | |
The tau protein (after the Greek letter tau ) is a protein that binds to supporting cytoskeletal proteins ( microtubules ) in animal cells and regulates their assembly. Mutations in the MAPT - gene can produce a variety of inherited diseases such as the human Pick's disease , corticobasal degeneration , progressive supranuclear palsy and HDDD- dementia cause. Neurodegenerative diseases with deposits of tau protein are summarized in the group of tauopathies . The best known tauopathy is Alzheimer's disease . Another tauopathy of increasing social relevance is chronic traumatic encephalopathy .
Post- transcriptional changes in the MAPT gene on chromosome 17 locus q21.2 lead to the fact that a total of six different isoforms can be detected in the human central nervous system . The alternative splicing of exons 2, 3 and 10 is of particular importance here . In particular for exon 10, several repetitions in some isoforms are known. The presence of 3 or 4 such tandem repeats in the microtubule binding site of the protein is used to classify the tauopathies into 3R and 4R tauopathies. A seventh, high-molecular tau isoform can also be detected in the peripheral nervous system.
When assembling into filamentary structures, the individual tau proteins are linked to one another via their repeating sections. The amino-terminal end is cut off. An abnormal hyper phosphorylation of the paired helical tau filaments (PHF) leads to a no longer functional protein, which can no longer interact with the microtubules. As a result of these pathological changes, the PHF deposits can be observed as neurofibrillary , intracellular aggregates in the brains of Alzheimer's patients. The first tau filaments can already be detected in the Locus caeruleus in some people in childhood and adolescence .