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Oncotarget. 2015 Dec 22;6(41):43557-70. doi: 10.18632/oncotarget.6196.

Negative regulation of EB1 turnover at microtubule plus ends by interaction with microtubule-associated protein ATIP3.

Author information

1
Inserm U981, Institut Gustave Roussy Department of Molecular Medicine, Villejuif, France.
2
Université Paris-Saclay, Villejuif, France.
3
CNRS UMR8104, Institut Cochin, Paris, France.
4
Cell Biology, Faculty of Science, Utrecht University, Padualaan, CH Utrecht, The Netherlands.
5
Cell and Tissue Imaging Core Facilty, PICT-IBiSA, CNRS UMR144 Institut Curie, Centre de Recherche, Paris, France.
6
Inserm U836, Grenoble Institut des Neurosciences, Grenoble, France.
7
Aix Marseille Université, Inserm, CRO2 UMR_S 911, Marseille, France.
8
APHM, Hôpital Timone, Marseille, France.
9
Scientific Partnerships Roche SAS, Boulogne Billancourt, France.

Abstract

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.

KEYWORDS:

+TIP; EB1; MTUS1; microtubule dynamics; protein interaction

PMID:
26498358
PMCID:
PMC4791250
DOI:
10.18632/oncotarget.6196
[Indexed for MEDLINE]
Free PMC Article

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