PathScan^® Phospho-Tau (Ser214) Sandwich ELISA Kit

Background

Tau is a heterogeneous microtubule-associated protein that promotes and stabilizes microtubule assembly, especially in axons. Six isoforms with different amino-terminal inserts and different numbers of tandem repeats near the carboxy terminus have been identified, and tau is hyperphosphorylated at approximately 25 sites by Erk, glycogen synthase kinase-3 (GSK-3), and CDK5 (1,2). Phosphorylation decreases the ability of tau to bind to microtubules. Neurofibrillary tangles are a major hallmark of Alzheimer's disease (AD); these tangles are bundles of paired helical filaments (PHFs) composed of hyperphosphorylated tau. In particular, phosphorylation at Ser396 by GSK-3 or CDK5 destabilizes microtubules. Furthermore, research studies have shown that inclusions of tau are found in a number of other neurodegenerative diseases, collectively known as tauopathies (1,3).

Numerous kinases including PKA, CDK5, GSK3β and SGK1 have been shown to phosphorylate tau at Ser214. In addition, investigators have shown that tau is phosphorylated at Ser214 in Alzheimer's disease and dementia with Lewy bodies (4-9). Investigators have shown that tau phosphorylation at Ser214 detaches tau protein from microtubules, protecting it against aggregation into Alzheimer paired helical filaments (10).