Tau proteins are proteins which contain four Tau/MAP repeats. They promote microtubule assembly and stability, and might be involved in the establishment and maintenance of neuronal polarity. They are abundant in neurons of the central nervous system and are less common elsewhere, but are also expressed at very low levels in CNS astrocytes and oligodendrocytes. The tau proteins are the product of alternative splicing from a single gene that in humans is designated MAPT. When tau proteins are defective, and no longer stabilize microtubules properly, they can result in several neurodegenerative disorders such as Alzheimer's disease, Pick's disease, frontotemporal dementia, cortico-basal degeneration and progressive supranuclear palsy.

MAPT (microtubule-associated protein tau) can produce tau proteins. Tau proteins are proteins that stabilize microtubules. They are abundant in neurons of the central nervous system and are less common elsewhere, but are also expressed at very low levels in CNS astrocytes and oligodendrocytes. When tau proteins are defective, and no longer stabilize microtubules properly, they can result in dementias such as Alzheimer's disease. Tau protein is a highly soluble microtubule-associated protein (MAP). In humans, these proteins are mostly found in neurons compared to non-neuronal cells. One of tau's main functions is to modulate the stability of axonal microtubules. Other nervous system MAPs may perform similar functions, as suggested by tau knockout mice, who did not show abnormalities in brain development - possibly because of compensation in tau deficiency by other MAPs.

Microtubule-Associated Protein TAU is abundantly expressed in neurons of the central nervous system and less commonly expressed elsewhere, but is also expressed at very low levels in CNS astrocytes and oligodendrocytes. Tau interacts with tubulin to stabilize microtubules and promotes tubulin assembly into microtubules. The C-terminus of TAU binds axonal microtubules while the N-terminus binds neural plasma membrane components, suggesting that tau acts as a linker protein. When tau is defective, and no longer stabilize microtubules properly, it can result in dementias such as Alzheimer's disease and other tauopathies.