title: Molecular mechanisms of Tau binding to microtubules and its role in microtubule dynamics in live cells.
abstract: Despite extensive studies, the molecular mechanisms of Tau binding to microtubules (MTs) and its consequences on MT stability still remain unclear. It is especially true in cells where the spatiotemporal distribution of Tau-MT interactions is unknown. Using Förster resonance energy transfer (FRET), we showed that the Tau-MT interaction was distributed along MTs in periodic hotspots of high and low FRET intensities. Fluorescence recovery after photobleaching (FRAP) revealed a two-phase exchange of Tau with MTs as a rapid diffusion followed by a slower binding phase. A real-time FRET assay showed that high FRET occurred simultaneously with rescue and pause transitions at MT ends. To further explore the functional interaction of Tau with MTs, the binding of paclitaxel (PTX), tubulin acetylation induced by trichostatin A (TSA), and the expression of non-acetylatable tubulin were used. With PTX and TSA, FRAP curves best fitted a single phase with a long time constant, whereas with non-acetylatable α-tubulin, curves best fitted a two phase recovery. Upon incubation with PTX and TSA, the number of high and low FRET hotspots decreased by up to 50% and no hotspot was observed during rescue and pause transitions. In the presence of non-acetylatable α-tubulin, a 34% increase in low FRET hotspots occurred, and our real-time FRET assay revealed that low FRET hotspots appeared with MTs recovering growth. In conclusion, we have identified, by FRET and FRAP, a discrete Tau-MT interaction, in which Tau could induce conformational changes of MTs, favoring recovery of MT self-assembly.
authors: Aix-Marseille Université, Inserm, CRO2 UMR_S 911, Faculté de Pharmacie 13385, Marseille, France. gilles.breuzard@univ-amu.fr
authors: Gilles
authors: G
authors: Breuzard
authors: Pierre
authors: P
authors: Hubert
authors: Roqiya
authors: R
authors: Nouar
authors: Tiphany
authors: T
authors: De Bessa
authors: François
authors: F
authors: Devred
authors: Pascale
authors: P
authors: Barbier
authors: James N
authors: JN
authors: Sturgis
authors: Vincent
authors: V
authors: Peyrot
mesh_terms: D000107:Acetylation; D001665:Binding Sites; D045744:Cell Line, Tumor; D036681:Fluorescence Recovery After Photobleaching; D031541:Fluorescence Resonance Energy Transfer; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology; D008870:Microtubules / Q000737:chemistry* / Q000378:metabolism; D057054:Molecular Imaging; D017239:Paclitaxel / Q000494:pharmacology; D011485:Protein Binding; D011487:Protein Conformation / Q000187:drug effects; D011499:Protein Processing, Post-Translational / Q000187:drug effects*; D014404:Tubulin / Q000737:chemistry* / Q000378:metabolism; D016875:tau Proteins / Q000737:chemistry* / Q000378:metabolism
chemical_list: D006877:Hydroxamic Acids; D014404:Tubulin; D016875:tau Proteins; C012589:trichostatin A; D017239:Paclitaxel
keywords: Cell; Fluorescence; Interaction; Microtubule-associated protein Tau; Tubulin