Amino acids 195-209 of the tubulin-related unit (tau). This region represents the tau trypsin peptide and is part of the core of the tau protein. Tau is a phosphoprotein involved in the assembly and stability of microtubules (MT) and brain development. Tau is phosphorylated by a variety of protein kinases at multiple sites, including cyclic AMP-dependent protein kinase and type 1 casein kinase. Tau phosphorylation causes tau to change shape, thereby negatively modulating its ability to stimulate MT assembly. Tau is also glycosylated, and O-glycosylation may play a role in its subcellular localization and degradation. The malfunctioning tau protein contributes to the structural core of the paired helical filaments (PHF) that make up the neurofibrillary tangles (NFT). NFT is frequently observed in neurodegenerative diseases such as Alzheimer's disease and other diseases. Tau is expressed by a single gene and is spliced into the adult central nervous system (CNS) to produce six different subtypes.
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