Abstract:

Tauopathies describe a group of neurodegenerative diseases in which the protein tau, encoded by the gene MAPT, is aberrantly misfolded, leading to tau aggregation, neural dysfunction, and cell death. In Alzheimer’s disease (AD), tau forms the characteristic intracellular neurofibrillary tangles (NFTs), which are thought to be the major cause of neurodegeneration. In other tauopathies, including frontotemporal dementia with Parkinsonism linked to chromosome 17 (FTDP-17T), corticobasal degeneration and progressive supranuclear palsy, there are specific forms of tau aggregates and filaments without any amyloid pathology, demonstrating tau’s potent disease-causing potential. Tau is a microtubule (MT) binding protein, which becomes abnormally hyperphosphorylated on several residues prior/during the process of aggregation, thereby causing loss of its MT binding activity. The importance of tau as a single cause of disease is reinforced by the identification of numerous (>55) mutations in autosomal-dominant forms of familial tauopathies, many of which occur in the MT binding domain. Indeed, more and more diseases are being uncovered in which aberrant phosphorylation and folding of tau is implicated, such as Huntington’s disease (HD), while MAPT is a genetic risk factor for Parkinson’s disease (PD), so it is of major interest to understand how it leads to cell dysfunction and death.