Tau protein in Alzheimer's disease, illustration. Pathological phosphorylation (yellow) of Tau proteins (red-orange) by kinases (blue-purple) affect nerve cells in what is called a neurofibrillary tangle. This illustration shows pathological aggregations of tau proteins causing disintegration of a microtubule (cylindrical structure). The transport of synaptic vesicles (orange-blue spheres, one at top left) is also interrupted. A neurofibrillary tangle consists of abnormal aggregates and insoluble fibres of the protein tau. Tau protein is an abundant neural protein, aggregations of which are thought to play a role in Alzheimer's disease and other neural disorders.