<p>GV1001, a peptide drug derived from human telomerase reverse transcriptase, has showed the therapeutic effect in the animal model of Alzheimer’s disease (AD), a representative chronic neurodegenerative disease having impaired learning and memory. In our previous studies, GV1001 has showed the multi-functions including anti-apoptosis, anti-oxidative stress, and anti-neuroinflammation in AD-related in vitro and in vivo systems. Here, in addition to these previously reported functions, GV1001 was discovered to reduce the protein level of 4R tau isoform in the pathological condition. There is no studies providing the potential of GV1001 as a therapeutic drug for neurodegenerative movement disorders. Progressive supranuclear palsy (PSP) is a rare atypical Parkinsonism in the midbrain region, leading to more severe motor symptoms and very rapid pathological progression. Increased 4R tau isoform in an affected brain region of the primary 4R tauopathy is a distinct pathological character in PSP patients. In this study, GV1001 down-regulated the protein level of 4R tau specifically in an annonacin-induced PSP in vitro neuronal model as well as in vivo study using 4R TauP301L-BiFC mouse model. These findings suggest a novel role of GV1001 in 4R tauopathy and support its disease-modifying potential within the context of 4R tau–driven neurodegenerative models, including PSP.</p>