Neurobiology
Tau isoform expression and phosphorylation in marmoset brains
Tau is a microtubule-associated protein expressed in neuronal axons. Hyperphosphorylated tau is a major component of neurofibrillary tangles, a pathological hallmark of Alzheimer’s disease (AD). Hyperphosphorylated tau aggregates are also found in many neurodegenerative diseases, collectively referred to as “tauopathies,” and tau mutations are associated with familial frontotemporal lobar degeneration (FTLD). Previous studies have generated transgenic mice with mutant tau as tauopathy models, but nonhuman primates, which are more similar to humans, may be a better model to study tauopathies.Isoform-independent and -dependent phosphorylation of microtubule-associated protein tau in mouse brain during postnatal development
Tau is a microtubule (MT)-associated protein that regulates MT dynamics in the axons of neurons. Tau binds to MTs via its C-terminal MT-binding repeats. There are two types of tau, those with three (3R) or four (4R) MT-binding repeats; 4R tau has a stronger MT-stabilizing activity than 3R tau. The MT-stabilizing activity of tau is regulated by phosphorylation. Interestingly, both the isoform and phosphorylation change at the time of neuronal circuit formation during postnatal development; highly phosphorylated 3R tau is replaced with 4R tau, which is less phosphorylated.
