Tau protein in Alzheimer's disease, illustration. Pathological phosphorylation (yellow) of Tau proteins (orange) by kinases (blue-purple) affect nerve cells in what is called a neurofibrillary tangle. This illustration shows the transport of synaptic vesicles (red-blue spheres) being interrupted. The tau proteins also affect microtubles (orange cylinders). 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.