Microtubule regulation in multi-cellular animals

Paul CONDUIT

Nous voulons acquérir une compréhension fondamentale de la manière dont la nucléation des microtubules est régulée spatio-temporellement dans le contexte des animaux pluricellulaires.

Nous sommes particulièrement intéressés par la façon dont les mécanismes régulant la formation et l’organisation des microtubules varient entre les types de cellules, y compris dans les cellules en division et les neurones.

Mots-clés : Microtubules, division cellulaire, neurones, gamma-tubuline, g-TuRC, MTOC, centrosome, drosophile

+33 (0)157278089     paul.conduit(at)ijm.fr     @PaulConduit

Research goal

We want to gain a fundamental understanding of how microtubule nucleation is spatiotemporally regulated within the context of multi-cellular animals. We are particularly interested in how the mechanisms regulating microtubule formation and organisation vary between cell types.

 

 

 

Background

Microtubules are dynamic polymers that make up part of the cell’s cytoskeleton. They form a spectacular variety of arrays across different cell types and developmental stages. For example, during cell division microtubules are arranged into the mitotic spindle, which separates the duplicated chromosomes equally between daughter cells. In mature neurons, however, microtubules are arranged into polarised networks that run through axons and dendrites. These networks are required for structural support, neurite growth, and transport of molecules between the cell body and the neurite terminals. All cells use the same fundamental machinery to generate and organise microtubules, so how do different cells form such different microtubule arrays?

 

Research programme

We are addressing this question by studying the molecular regulation of multi-protein γ-tubulin ring complexes (γ-TuRCs), which template and catalyse de novo microtubule formation. γ-TuRCs are recruited and activated at specific sites within the cells in order to generate new microtubules at the right place and time. These sites include microtubule organising centres (MTOCs), such as centrosomes during mitosis or the Golgi in migrating fibroblasts, the sides of pre-existing microtubules, or specialised regions of cytoplasm, such as the cytosol surrounding mitotic chromatin. Once generated, molecular motors can slide microtubules against one another or even guide the direction of microtubule growth. Microtubules can also be stabilised by post-translational modifications or binding of other proteins. While not a focus of the lab, we are also interested in these post-nucleated processes as collectively they are important for correct microtubule array formation.

 

Main research areas currently within the lab

  • Investigating the molecular mechanisms regulating γ-TuRC recruitment and activation at different MTOCs
  • Understanding how microtubule formation and polarity are regulated within neurons.

 

 

Methodology

We predominantly use Drosophila as an in vivo multi-cellular animal model system. We combine precise manipulation of the genome, fixed and live advanced cell imaging, and biochemical assays to probe the molecular regulation of microtubules and the effect of their mis-regulation within cells.

 

Impact

Our work has implications for cancer and neurodegenerative disease, as γ-TuRCs have been identified as potential anti-cancer targets and microtubules form part of an important response during neuronal stress.

Group leader :

Paul CONDUIT
Phone : +33 (0)157278089
paul.conduit(at)ijm.fr

 

Members :

Adria CHORRO Doctorant
Akila MERAH YAGOUBAT Postdoctorante
Corinne TOVEY Postdoctorante

Abir ELFARKOUCHI (PhD stident)

Isabel BECAM (Assistant professor)

Zhu Z, Tovey CA, Yen EC, Bernard F, Guichet A, ConduitP#. (2022) Multifaceted modes of γ-tubulin complex recruitment and microtubule nucleation at mitotic centrosomes. BioRxiv. 10.1101/2022.09.23.509043

Mukherjee A and Conduit P#. (2021). γ-TuRCs are required for asymmetric microtubule nucleation from the somatic Golgi of Drosophila neurons. BioRxiv. doi:10.1101/2021.09.24.461707.

Cunningham NHJ, Bouhlel IB, Conduit PT*. Daughter centrioles assemble preferentially towards the nuclear envelope in Drosophila syncytial embryos. Open biology 12 (1), 210343

Tovey CA, Tsuji C, Egerton A, Bernard F, Guichet A, de la Roche M, Conduit PT*. (2021). Auto-inhibition of Cnn binding to γ-TuRCs prevents ectopic microtubule nucleation and cell division defects. JCB. 10.1083/jcb.202010020.

Mukherjee A, Brooks P, Bernard F, Guichet A, Conduit PT*. (2020). Microtubules originate asymmetrically at the somatic Golgi and are guided via Kinesin2 to maintain polarity within neurons. eLife. 2020;9:e58943. [link]

Mukherjee A and Conduit PT*. (2019). γ-TuRCs (quick guide). Current Biology. [link]

Tovey CA, Tubman CE, Hamrud E, Zhu Z, Dyas AE, Butterfield AN, Fyfe A, Johnson E, Conduit PT*. (2018). γ-TuRC heterogeneity revealed by analysis of Mozart1. Current Biology 28, 2314-2323. [link]

Tovey CA and Conduit PT*. (2018). Microtubule nucleation by γ-tubulin complexes and beyond. Essays in Biochemistry. DOI: 10.1042/EBC20180028 [link]

Depuis 2015 :

Cunningham NHJ, Bouhlel IB, Conduit PT*. Daughter centrioles assemble preferentially towards the nuclear envelope in Drosophila syncytial embryos. Open biology 12 (1), 210343

 

Tovey CA, Tsuji C, Egerton A, Bernard F, Guichet A, de la Roche M, Conduit PT*. (2021). Auto-inhibition of Cnn binding to γ-TuRCs prevents ectopic microtubule nucleation and cell division defects. JCB. 10.1083/jcb.202010020.

 

Mukherjee A, Brooks P, Bernard F, Guichet A, Conduit PT*. (2020). Microtubules originate asymmetrically at the somatic Golgi and are guided via Kinesin2 to maintain polarity within neurons. eLife. 2020;9:e58943. [link]

 

Mukherjee A and Conduit PT*. (2019). γ-TuRCs (quick guide). Current Biology. [link]

 

Alvarez-Rodrigo I, Steinacker TL, Saurya S, Conduit PT, Baumbach J, Novak ZA, Aydogen MG, Wainman A, Raff JW*. (2019). Evidence that a positive feedback loop drives centrosome maturation in fly embryos. eLife DOI: 10.7554/eLife.50130

 

Tovey CA, Tubman CE, Hamrud E, Zhu Z, Dyas AE, Butterfield AN, Fyfe A, Johnson E, Conduit PT*. (2018). γ-TuRC heterogeneity revealed by analysis of Mozart1. Current Biology 28, 2314-2323. [link]

 

Tovey CA and Conduit PT*. (2018). Microtubule nucleation by γ-tubulin complexes and beyond. Essays in Biochemistry. DOI: 10.1042/EBC20180028 [link]

 

Feng Z, Caballe A, Wainman A, Johnson S, Haensele AFM, Cottee MA, Conduit PT, Susan M. Lea*, Jordan W. Raff*. (2017). Structural Basis for Mitotic Centrosome Assembly in Flies. Cell 169, 1078–1089. [link]

 

Conduit PT*. (2016). Microtubule organization: A complex solution. Journal of Cell Biology 213(6):609-12

 

Conduit PT, Wainman A,  Raff JW*. (2015). Centrosome function and assembly in animal cells. Nature Reviews Molecular Cell Biology, 16, 611–624.

 

Conduit PT, Hayward D, Wakefield JG* (2015). Microinjection techniques for studying centrosome function in Drosophila melanogaster syncytial embryos. Methods Cell Biol. 2015;129:229-49. doi:10.1016/bs.mcb.2015.03.007.

 

Conduit PT, Wainman A, Novak ZA, Raff JW*. (2015). Re-examining the role of Drosophila Sas-4 in centrosome assembly using two-colour-3D-SIM FRAP. eLife DOI: http://dx.doi.org/10.7554/eLife.08483.

Conduit PT and Raff JW*. (2015). Different Drosophila cell types exhibit important differences in mitotic centrosome assembly dynamics. Current Biology, 25: pR650-R651.

Regulation of gamma-tubulin ring complex. C A Tovey

Regulation of microtubules by Patronin. P S Brooks

Studying the role of the Augmin complex in dendritic arborisation neruons. Y N A Jeske

Investigating the mechanisms of microtubule organisation at mitotic centrosomes in Drosophila. Z Zhu

Antoine Guichet, Susan Lea, Emmanuel Derivery, Natalia Sanchez-Soriano

ATIP-Avenir

Fondation Bettencourt-Schueller

Université Paris Cité