Microtubule In Vitro Bundle Structures Depends On Tau Projection Domain And Ionic Strength

In neurons, the bundles of Microtubules (MTs) function as tracks for transportation through axon. Microtubules (MTs) are anionic protein nanotubes comprised of αβ heterodimeric tubulins. Microtubule-associated protein (MAP) Tau binds to MTs and regulates tubulin assembly and MT stability. Dysfunction of Tau leads to numerous neurodegenerative diseases including Alzheimer's, Pick's, supranuclear palsy, and fronto-temporal dementia with Parkinsonism linked to chromosome 17 (FTDP-17). Tau is an intrinsically disordered protein (IDP) and polyampholyte that has both positively and negatively charged region in single chain. In this poster, we present our recent findings on triggering electrostatically bundle-to-nonbundle phase transitions of Tau and MTs by using synchrotron small angle X-ray scattering (SAXS).