PTau 181

Phosphorylation at threonine 181 (PTau 181) is a critical post-translational modification of the tau protein, which plays a vital role in stabilizing microtubules within neurons. This modification is regulated by various kinases, including tau tubulin kinase 2 (TTBK2), a serine-threonine kinase encoded by the TTBK2 gene. Mutations in TTBK2 have been linked to spinocerebellar ataxia type 11 (SCA11), a neurodegenerative disorder characterized by progressive ataxia and cerebellar atrophy.

PTau 181 influences its interaction with microtubules. Hyperphosphorylation at this site can lead to tau dissociation from microtubules, resulting in microtubule destabilization and impaired axonal transport. This process is associated with various tauopathies, where abnormal tau phosphorylation and aggregation contribute to neurodegeneration.

Research has shown that PTau 181 can accumulate in the serum under certain physiological conditions. For instance, studies on hibernating animals have indicated a substantial increase in serum PTau 181 levels during hibernation, which normalize upon arousal. This suggests that PTau 181 dynamics may be influenced by metabolic or environmental factors, highlighting the complexity of tau regulation in different physiological states.