Truncated Tau - Role of the Tau N-terminal region in microtubule stabilization revealed by new endogenous truncated forms

ABSTRACT: Tau is a microtubule-associated protein that ensures neuronal shape and function. Besides, Tau is a central player in Alzheimer’s disease (AD) and related Tauopathies where it is found aggregated in degenerating neurons. Mechanisms leading to Tau pathology and its progression are far from being elucidated. Among Tau species found in AD brains, several yet unidentified truncated Tau fragments are showed. A major step forward in the understanding of the role of Tau truncation would be to identify the precise cleavage sites of Tau species. This key step is mandatory to generate appropriate experimental tools in order to investigate the impact of each identified truncated-species on Tau function/dysfunction. Here, we achieved an optimized proteomics approach and succeed in identifying a number of new N-terminally truncated-Tau species from human brain. As N-terminal residues of these fragments are located broadly across Tau sequence, one could expect to have different effects on Tau. We initiated cell-based functional studies by analyzing biochemical characteristics of two N-terminally truncated Tau species starting at residues Met11 and Gln124 (accordingly to the longest Tau isoform) regarding Tau microtubule function. Our results surprisingly showed that the ability of Tau to bind and stabilize microtubules was greater when the first 123 residues are truncated, suggesting that Tau N-terminus would have a role in regulation of microtubule stabilization. Overall, future studies based on our new N-terminally truncated-Tau species will provide new knowledge on the role of truncation in Tau biology as well as in AD pathological process.

INSTRUMENT(S): LTQ FT

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Brain

DISEASE(S): Alzheimer's Disease

SUBMITTER: Yann Verdier  

LAB HEAD: Joelle VINH

PROVIDER: PXD001353 | Pride | 2015-05-15

REPOSITORIES: Pride