The nuclear F-actin interactome of Xenopus oocytes reveals an actin-bundling kinesin that is essential for meiotic cytokinesis
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Matthias Samwer [2] ; Heinz-Jürgen Dehne [2] ; Felix Spira [1] ; Martin Kollmar [3] ; Daniel W Gerlich [1] ; Henning Urlaub [4] ; Dirk Görlich [2]
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[1] Institute of Molecular Biotechnology
Institute of Molecular Biotechnology
Innere Stadt, Austria
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[2] Department of Cellular Logistics, MPI for Biophysical Chemistry, Göttingen, Germany
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[3] Systems Biology of Motor Proteins Group, MPI for Biophysical Chemistry, Göttingen, Germany
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[4] Bioanalytical Mass Spectrometry Group, MPI for Biophysical Chemistry, Göttingen, Germany
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- Localización: EMBO journal: European Molecular Biology Organization, ISSN 0261-4189, Vol. 32, Nº. 13, 2013, págs. 1886-1902
- Idioma: inglés
- Enlaces
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Resumen
Nuclei of Xenopus laevis oocytes grow 100 000-fold larger in volume than a typical somatic nucleus and require an unusual intranuclear F-actin scaffold for mechanical stability. We now developed a method for mapping F-actin interactomes and identified a comprehensive set of F-actin binders from the oocyte nuclei. Unexpectedly, the most prominent interactor was a novel kinesin termed NabKin (Nuclear and meiotic actin-bundling Kinesin). NabKin not only binds microtubules but also F-actin structures, such as the intranuclear actin bundles in prophase and the contractile actomyosin ring during cytokinesis. The interaction between NabKin and F-actin is negatively regulated by Importin-β and is responsive to spatial information provided by RanGTP. Disconnecting NabKin from F-actin during meiosis caused cytokinesis failure and egg polyploidy. We also found actin-bundling activity in Nabkin's somatic paralogue KIF14, which was previously shown to be essential for somatic cell division. Our data are consistent with the notion that NabKin/KIF14 directly link microtubules with F-actin and that such link is essential for cytokinesis.
