Tau protein promotes microtubule assembly and stability. Tau is also involved in the establishment and maintenance of neural polarity. The C-terminus domain of Tau binds to a, Xenopus/Amphibian,onal microtubules whereas the N-terminus domain binds to neural plasma membrane components, therefore suggesting that Tau protein functions as a linker between the two. A, Xenopus/Amphibian,onal polarity is predetermined by tau localization in the domain of the cell body defined by the centrosome. The short isoforms allow plasticity of the cytoskeleton whereas the longer isoforms may preferentially play a role in its stabilization. PNS-tau is e, Xenopus/Amphibian,pressed in the peripheral nervous system whereas the other isoforms are e, Xenopus/Amphibian,pressed in the central nervous system. Defects in Tau protein are a cause of dementia,Porcinearkinsonism and Alzheimer disease.