Negative regulation of EB1 turnover at microtubule plus ends by interaction with microtubule-associated protein ATIP3.
The regulation of microtubule dynamics is critical to ensure essential cell functions. End binding protein 1 (EB1) is a master regulator of microtubule dynamics that autonomously binds an extended GTP/GDP-Pi structure at growing microtubule ends and recruits regulatory proteins at this location. However, negative regulation of EB1 association with growing microtubule ends remains poorly understood. We show here that microtubule-associated tumor suppressor ATIP3 interacts with EB1 through direct binding of a non-canonical proline-rich motif. Results indicate that ATIP3 does not localize at growing microtubule ends and that in situ ATIP3-EB1 molecular complexes are mostly detected in the cytosol. We present evidence that a minimal EB1-interacting sequence of ATIP3 is both necessary and sufficient to prevent EB1 accumulation at growing microtubule ends in living cells and that EB1-interaction is involved in reducing cell polarity. By fluorescence recovery of EB1-GFP after photobleaching, we show that ATIP3 silencing accelerates EB1 turnover at microtubule ends with no modification of EB1 diffusion in the cytosol. We propose a novel mechanism by which ATIP3-EB1 interaction indirectly reduces the kinetics of EB1 exchange on its recognition site, thereby accounting for negative regulation of microtubule dynamic instability. Our findings provide a unique example of decreased EB1 turnover at growing microtubule ends by cytosolic interaction with a tumor suppressor.
Inserm U981, Institut Gustave Roussy Department of Molecular Medicine, Villejuif, France.|Université Paris-Saclay, Villejuif, France.|CNRS UMR8104, Institut Cochin, Paris, France.
Lauriane
L
Velot
Inserm U981, Institut Gustave Roussy Department of Molecular Medicine, Villejuif, France.|Université Paris-Saclay, Villejuif, France.|CNRS UMR8104, Institut Cochin, Paris, France.
Angie
A
Molina
Inserm U981, Institut Gustave Roussy Department of Molecular Medicine, Villejuif, France.|Université Paris-Saclay, Villejuif, France.|CNRS UMR8104, Institut Cochin, Paris, France.
Sylvie
S
Rodrigues-Ferreira
Inserm U981, Institut Gustave Roussy Department of Molecular Medicine, Villejuif, France.|Université Paris-Saclay, Villejuif, France.
Anne
A
Nehlig
Cell Biology, Faculty of Science, Utrecht University, Padualaan, CH Utrecht, The Netherlands.
Benjamin Pierre
BP
Bouchet
CNRS UMR8104, Institut Cochin, Paris, France.
Marina
M
Morel
Cell and Tissue Imaging Core Facilty, PICT-IBiSA, CNRS UMR144 Institut Curie, Centre de Recherche, Paris, France.
Ludovic
L
Leconte
Inserm U836, Grenoble Institut des Neurosciences, Grenoble, France.
Laurence
L
Serre
Inserm U836, Grenoble Institut des Neurosciences, Grenoble, France.
Isabelle
I
Arnal
Aix Marseille Université, Inserm, CRO2 UMR_S 911, Marseille, France.|APHM, Hôpital Timone, Marseille, France.
Diane
D
Braguer
Scientific Partnerships Roche SAS, Boulogne Billancourt, France.
Ariel
A
Savina
Aix Marseille Université, Inserm, CRO2 UMR_S 911, Marseille, France.|APHM, Hôpital Timone, Marseille, France.
Stéphane
S
Honore
Inserm U981, Institut Gustave Roussy Department of Molecular Medicine, Villejuif, France.|Université Paris-Saclay, Villejuif, France.|CNRS UMR8104, Institut Cochin, Paris, France.
Clara
C
Nahmias
D002460:Cell Line; D016764:Cell Polarity; D005455:Fluorescent Antibody Technique; D006801:Humans; D047468:Immunoprecipitation; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism*; D014162:Transfection; D025521:Tumor Suppressor Proteins / Q000378:metabolism*
C500985:MAPRE1 protein, human; C474762:MTUS1 protein, human; D008869:Microtubule-Associated Proteins; D025521:Tumor Suppressor Proteins
+TIP; EB1; MTUS1; microtubule dynamics; protein interaction