Akt regulates centrosome migration and spindle orientation in the early Drosophila melanogaster embryo.
Journal of Cell Biology
Rockefeller University Press
Correct positioning and morphology of the mitotic spindle is achieved through regulating the interaction between microtubules (MTs) and cortical actin. Here we find that, in the Drosophila melanogaster early embryo, reduced levels of the protein kinase Akt result in incomplete centrosome migration around cortical nuclei, bent mitotic spindles, and loss of nuclei into the interior of the embryo. We show that Akt is enriched at the embryonic cortex and is required for phosphorylation of the glycogen synthase kinase-3beta homologue Zeste-white 3 kinase (Zw3) and for the cortical localizations of the adenomatosis polyposis coli (APC)-related protein APC2/E-APC and the MT + Tip protein EB1. We also show that reduced levels of Akt result in mislocalization of APC2 in postcellularized embryonic mitoses and misorientation of epithelial mitotic spindles. Together, our results suggest that Akt regulates a complex containing Zw3, Armadillo, APC2, and EB1 and that this complex has a role in stabilizing MT-cortex interactions, facilitating both centrosome separation and mitotic spindle orientation.
addresses: Department of Zoology, University of Oxford, Oxford OX1 3PS, England, UK.
notes: PMCID: PMC2234228
types: Journal Article; Research Support, Non-U.S. Gov't
© 2008 Rockefeller University Press
Journal of Cell Biology, 2008, Vol. 180, Issue 3, pp. 537 - 548
Place of publication