Tau Proteins Harboring Neurodegeneration-Linked Mutations Impair Kinesin Translocation in vitro

Article type: Research Article

Authors: Yu, Dezhi^{a; 1} | LaPointe, Nichole E.^{b; c; 1} | Guzman, Elmer^{b; c} | Pessino, Veronica^{d; 2} | Wilson, Leslie^{b; c} | Feinstein, Stuart C.^{b; c; *} | Valentine, Megan T.^{b; e}

Affiliations: [a] Department of Materials, University of California, Santa Barbara, CA, USA | [b] Neuroscience Research Institute, University of California, Santa Barbara, CA, USA | [c] Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA, USA | [d] College of Creative Studies, University of California, Santa Barbara, CA, USA | [e] Department of Mechanical Engineering, University of California, Santa Barbara, CA, USA

Correspondence: [*] Correspondence to: Stuart C. Feinstein, University of California, Santa Barbara, Biology II Building, Room 5123, Santa Barbara, CA 93106-5070, USA. Tel.: +1 805 893 2659; Fax: +1 805 893 2005; E-mail: stu.feinstein@lifesci.ucsb.edu.

Note: [1] These authors contributed equally to this work.

Note: [2] Current address: Integrative Program in Quantitative Biology, Biophysics, University of California, San Francisco, CA, USA.

Abstract: We tested the hypothesis that mutant tau proteins that cause neurodegeneration and dementia differentially alter kinesin translocation along microtubules (MTs) relative to normal tau in vitro. We employed complementary in vitro motility assays using purified recombinant kinesin, purified recombinant tau, and purified bovine brain α:β tubulin to isolate interactions among these components without any contribution by cellular regulatory mechanisms. We found that kinesin translocates slower along MTs assembled by any of three independent tau mutants (4-repeat P301L tau, 4-repeat ΔN296 tau, and 4-repeat R406W tau) relative to its translocation rate along MTs assembled by normal, 4-repeat wild type (WT) tau. Moreover, the R406W mutation exhibited isoform specific effects; while kinesin translocation along 4-repeat R406W tau assembled MTs is slower than along MTs assembled by 4-repeat WT tau, the R406W mutation had no effect in the 3-repeat tau context. These data provide strong support for the notion that aberrant modulation of kinesin translocation is a component of tau-mediated neuronal cell death and dementia. Finally, we showed that assembling MTs with taxol before coating them with mutant tau obscured effects of the mutant tau that were readily apparent using more physiologically relevant MTs assembled with tau alone, raising important issues regarding the use of taxol as an experimental reagent and novel insights into therapeutic mechanisms of taxol action.

Keywords: Axonal transport, corticobasal degeneration, frontotemporal dementia with parkinsonism-17, kinesin, microtubules, motility, progressive supranuclear palsy, tau

DOI: 10.3233/JAD-131274

Journal: Journal of Alzheimer's Disease, vol. 39, no. 2, pp. 301-314, 2014