期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2014
卷号：111
期号：17
页码：6311-6316
DOI：10.1073/pnas.1315983111
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Tau is a microtubule binding protein that forms pathological aggregates in the brain in Alzheimer's disease and other tauopathies. Disease etiology is thought to arise from loss of native interactions between tau and microtubules, as well as from gain of toxicity tied to tau aggregation, although neither mechanism is well understood. Here we investigate the link between function and disease using disease-associated and disease-motivated mutants of tau. We find that mutations to highly conserved proline residues in repeats 2 and 3 of the microtubule binding domain have differential effects on tau binding to tubulin and the capacity of tau to enhance tubulin polymerization. Notably, mutations to these residues result in an increased affinity for tubulin dimers while having a negligible effect on binding to stabilized microtubules. We measure conformational changes in tau on binding to tubulin that provide a structural framework for the observed altered affinity and function. Additionally, we find that these mutations do not necessarily enhance aggregation, which could have important implications for tau therapeutic strategies that focus solely on searching for tau aggregation inhibitors. We propose a model that describes tau binding to tubulin dimers and a mechanism by which disease-relevant alterations to tau impact its function. Together, these results draw attention to the interaction between tau and free tubulin as playing an important role in mechanisms of tau pathology.
关键词：microtubule-associated protein ; intrinsically disordered proteins ; single molecule FRET
