Regulation of microtubule/actin interplay by Tau

Objectives

The main objectives of this project are 1) to reconstitute in a cell-free environment, the co-assembly of microtubule and actin cytoskeletons, 2) to determine how Tau control the interplay between microtubule and actin, 3) to evaluate how pathological variants of Tau affect microtubule/actin interactions.

Abstract

The cytoskeleton regulates major biological functions such as cell differentiation, cell migration and cell division. Importantly, actin microfilaments and microtubules interact with each other, and this interaction seems key for some cellular functions in eukaryotic cells. Yet, the mechanisms underlying actin/microtubule crosstalk are still unclear. We recently found that Tau, a major microtubule regulator in neurons, is also able to bind actin filaments. Strikingly in many brain diseases, Tau is abnormally modified and induces cytoskeleton defects. Moreover Tau modifications are also associated with bad prognosis in some cancers. In this context, the aim of this internship is to determine the how Tau regulates microtubule/actin interplay using biomimetic assays that reconstitute cytoskeleton networks from purified proteins. This Learning-By-Building approach will enable us to decipher the molecular mechanisms underlying the cytoskeleton defects induced by pathological variants of Tau.

Methods

Protein expression (bacteria) and purification (chromatography, affinity), co-sedimentation assays, SDS-PAGE. Bio-mimetic assays. Imaging (video-microscopy, TIRF) and image analysis (ImageJ).

Reference

* Elie et al. (2015) Tau co-organizes dynamic microtubule and actin networks. Sci Rep 5:9964
* Stoppin-Mellet et al. (2020) Studying Tau-Microtubule interaction using single-molecule TIRF microscopy. Methods Mol Biol 2101:77-91
* Fourest-Lieuvin et al. (2023) Controlled Tau cleavage in cells reveals abnormal localizations of Tau fragments. Neuroscience 518:162-177.

Requested domains of expertise

Cytoskeleton — Protein biochemistry — Fluorescence microscopy — Data analysis

Contact

Virginie Stoppin-Mellet, MCF
Email : %20virginie.stoppin-melletuniv-grenoble-alpes.fr (virginie[dot]stoppin-mellet[at]univ-grenoble-alpes[dot]fr)
Phone : +33 (0)4 56 52 06 89