RT Journal Article
SR Electronic
T1 The Centrosome Controls the Number and Spatial Distribution of Microtubules by Negatively Regulating Alternative MTOCs
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 153304
DO 10.1101/153304
A1 Maria P. Gavilan
A1 Pablo Gandolfo
A1 Fernando R. Balestra
A1 Francisco Arias
A1 Michel Bornens
A1 Rosa M. Rios
YR 2017
UL http://biorxiv.org/content/early/2017/06/21/153304.abstract
AB In this work, we have investigated in mammalian cells how microtubule nucleation at centrosome and Golgi apparatus are coordinated, using genetic ablation of three γ-TuRC binding proteins -AKAP450, Pericentrin and CDK5Rap2- and the PLK4 inhibitor centrinone. We show that centrosomal microtubule nucleation is independent of Golgi activity whereas the converse is not true: nucleation on the Golgi negatively correlates with the number of centrosomes. In addition, depleting AKAP450 in cells lacking centrioles, that abolishes Golgi nucleation activity, leads to microtubule nucleation from numerous cytoplasmic Golgi-unbound acentriolar structures containing Pericentrin, CDK5Rap2 and y-tubulin. Strikingly, centrosome-less cells display twice higher microtubule density than normal cells, suggesting that the centrosome controls the spatial distribution of microtubules, not only by nucleating them, but also by acting as a negative regulator of alternative MTOCs. Collectively, the data reveals a hierarchical control of microtubule nucleation, with the centrosome regulating this process in a more complex manner than usually thought. It also unveils mechanisms that could help understanding MT network reorganization during cell differentiation.AbAntibodyCTRCentrosomeGAGolgi apparatusIFImmunofluorescenceIPImmunoprecipitationMTMicrotubuleMTOCMicrotubule-organizing centerNZNocodazolePACT-domainPCNT-AKAP450 centrosomal targetingPCMPericentriolar materialKOKnock-outWBWestern blot