Microtubule-associated protein tau (MAPT) N-terminal epitope (residues 2–18) (Tau 2–18)

The pathological tau N-terminal epitope (residues 2–18), also known as the Phosphatase Activating Domain (PAD), is a specific sequence within the microtubule-associated protein tau (MAPT) that becomes abnormally exposed during the early stages of tau pathology (Kanaan et al., 2011, J. Neurosci.). In healthy neurons, tau is an intrinsically disordered protein that stabilizes microtubules; however, in tauopathies like Alzheimer's disease, conformational changes lead to the exposure of the PAD. This exposed region triggers a signaling cascade involving protein phosphatase 1 (PP1) and glycogen synthase kinase 3 (GSK3), which inhibits fast axonal transport and contributes to synaptic dysfunction and neurodegeneration (Cox et al., 2016, J. Alzheimers Dis.). Therapeutic strategies targeting this epitope, such as the monoclonal antibody TNT-1 or clinical candidates like APNmAb005, aim to neutralize this toxic signaling and prevent the spread of pathological tau species (Asceneuron, 2023). By binding specifically to the 2–18 region, these agents seek to preserve neuronal transport mechanisms and slow the progression of cognitive decline in patients with neurodegenerative diseases.

Other names

Phosphatase Activating DomainPADTau N-terminal domainTNT-1 epitopeTau(2-18)N-terminal tau epitope

Passive immunotherapy targeting the N-terminal Phosphatase Activating Domain (PAD) to neutralize toxic signaling and prevent the inhibition of fast axonal transport.