Single-molecule tracking of tau reveals fast kiss-and-hop interaction with microtubules in living neurons.
Bottom Line: Furthermore, we observed by quantitative imaging using fluorescence decay after photoactivation recordings of photoactivatable GFP-tagged tubulin that, despite this rapid dynamics, tau is capable of regulating the tubulin-microtubule balance.Our data imply a novel kiss-and-hop mechanism by which tau promotes neuronal microtubule assembly.The rapid kiss-and-hop interaction explains why tau, although binding to microtubules, does not interfere with axonal transport.
Affiliation: Department of Neurobiology, University of Osnabrück, D-49076 Osnabrück, Germany.Show MeSH
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Mentions: The spatial resolution of single-molecule tracking (∼20 nm) was high enough to discriminate between tau being attached to one particular MT or to its neighbor in processes of PC12 cells (Figure 2A). Note that the spacing between MTs in PC12 neurites is ∼70 nm (Jacobs and Stevens, 1986), a much higher value than the typical MT–MT distance in axons (Hirokawa and Takemura, 2005) due to the fact that PC12 cells do not develop axonal compartmentalization. Figure 2B (see also Supplemental Movie S2) documents the “pseudotrajectory” of binding events of tau over time (for a real trajectory, see Figure 2C). It is also evident that tau binds to several neighboring MTs in the transversal direction during the recording time (Figure 2B).
Affiliation: Department of Neurobiology, University of Osnabrück, D-49076 Osnabrück, Germany.