Isoform Tau-E of Microtubule-associated protein tau

Isoform Tau-E is a 42.9 kDa splice variant of microtubule-associated protein tau (MAPT), a regulatory protein that binds to and stabilizes microtubules in neurons (UniProt: P10636-7). Tau plays a central role in axonal transport and cytoskeletal organization; its dysregulation is implicated in neuronal dysfunction and cell death.

Tau is predominantly expressed in the nervous system and is a hallmark pathological feature of Alzheimer's disease, where it accumulates as hyperphosphorylated tangles in neurons and glia (UniProt: P10636-7). The protein's aggregation is thought to contribute to neurodegeneration and cognitive decline in AD and related tauopathies.

This isoform shows elevated abundance in post-mortem Alzheimer's disease brain tissue compared to age-matched controls, with a mean log2 fold-change of 0.919 across two subcellular fractions in a four-fraction proteomics study (Chaparral AD proteomics). The upregulation suggests that Tau-E may be specifically enriched or accumulated in AD pathology, consistent with tau's role as a central molecular hallmark of the disease.