Phospho-Tau Family Antibody Sampler 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).

Investigators have shown that Tau phosphorylation at Ser404 destabilizes microtubules and that Tau is hyperphosphorylated at Ser404 in Alzheimer's disease (2,4-6). Research studies indicate that calcium-/calmodulin-dependent protease kinase II (CAM-kkinase II) is responsible for the phosphorylation of Tau at Ser416. Phosphorylated Tau protein is localized with neuronal soma or hippocampal neurons and immortalized GnRH neurons (7). Investigators have shown that Tau is phosphorylated during development and hyperphosphorylated at Ser202 in Alzheimer's disease (8).