Post-translational modifications of tau protein: implications for Alzheimer's disease

Alzheimer's disease (AD) belongs to a group of neurodegenerative diseases collectively designated as "tauopathies", because they are characterized by the aggregation of abnormally phosphorylated tau protein. The mechanisms responsible for tau aggregation and its contribution to neurodegeneration are still unknown. Thereby, understanding the modes of regulation of tau is of high interest in the determination of the possible causes at the origin of the formation of tau aggregates and to elaborate protection strategies to cope with these pathological lesions. The regulation of tau takes place predominantly through post-translational modifications. Extensive reports have been published about tau phosphorylation; however, the other tau post-translational modifications have received much less attention. Here, we review the different types of post-translational modifications of tau including phosphorylation, glycosylation, glycation, prolyl-isomerization, cleavage or truncation, nitration, polyamination, ubiquitination, sumoylation, oxidation and aggregation, with a particular interest towards their relevance in AD.