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CaM kinase II initiates meiotic spindle depolymerization independently of APC/C activation

Altered spindle microtubule dynamics at anaphase onset are the basis for chromosome segregation. In Xenopus laevis egg extracts, increasing free calcium levels and subsequently rising calcium-calmodulin–dependent kinase II (CaMKII) activity promote a release from meiosis II arrest and reentry into a...

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Detalles Bibliográficos
Autores principales: Reber, Simone, Over, Sabine, Kronja, Iva, Gruss, Oliver J.
Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 2008
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2600749/
https://www.ncbi.nlm.nih.gov/pubmed/19064669
http://dx.doi.org/10.1083/jcb.200807006
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author Reber, Simone
Over, Sabine
Kronja, Iva
Gruss, Oliver J.
author_facet Reber, Simone
Over, Sabine
Kronja, Iva
Gruss, Oliver J.
author_sort Reber, Simone
collection PubMed
description Altered spindle microtubule dynamics at anaphase onset are the basis for chromosome segregation. In Xenopus laevis egg extracts, increasing free calcium levels and subsequently rising calcium-calmodulin–dependent kinase II (CaMKII) activity promote a release from meiosis II arrest and reentry into anaphase. CaMKII induces the activation of the anaphase-promoting complex/cyclosome (APC/C), which destines securin and cyclin B for degradation to allow chromosome separation and mitotic exit. In this study, we investigated the calcium-dependent signal responsible for microtubule depolymerization at anaphase onset after release from meiotic arrest in Xenopus egg extracts. Using Ran–guanosine triphosphate–mediated microtubule assemblies and quantitative analysis of complete spindles, we demonstrate that CaMKII triggers anaphase microtubule depolymerization. A CaMKII-induced twofold increase in microtubule catastrophe rates can explain reduced microtubule stability. However, calcium or constitutively active CaMKII promotes microtubule destabilization even upon APC/C inhibition and in the presence of high cyclin-dependent kinase 1 activity. Therefore, our data demonstrate that CaMKII turns on parallel pathways to activate the APC/C and to induce microtubule depolymerization at meiotic anaphase onset.
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spelling pubmed-26007492009-06-15 CaM kinase II initiates meiotic spindle depolymerization independently of APC/C activation Reber, Simone Over, Sabine Kronja, Iva Gruss, Oliver J. J Cell Biol Research Articles Altered spindle microtubule dynamics at anaphase onset are the basis for chromosome segregation. In Xenopus laevis egg extracts, increasing free calcium levels and subsequently rising calcium-calmodulin–dependent kinase II (CaMKII) activity promote a release from meiosis II arrest and reentry into anaphase. CaMKII induces the activation of the anaphase-promoting complex/cyclosome (APC/C), which destines securin and cyclin B for degradation to allow chromosome separation and mitotic exit. In this study, we investigated the calcium-dependent signal responsible for microtubule depolymerization at anaphase onset after release from meiotic arrest in Xenopus egg extracts. Using Ran–guanosine triphosphate–mediated microtubule assemblies and quantitative analysis of complete spindles, we demonstrate that CaMKII triggers anaphase microtubule depolymerization. A CaMKII-induced twofold increase in microtubule catastrophe rates can explain reduced microtubule stability. However, calcium or constitutively active CaMKII promotes microtubule destabilization even upon APC/C inhibition and in the presence of high cyclin-dependent kinase 1 activity. Therefore, our data demonstrate that CaMKII turns on parallel pathways to activate the APC/C and to induce microtubule depolymerization at meiotic anaphase onset. The Rockefeller University Press 2008-12-15 /pmc/articles/PMC2600749/ /pubmed/19064669 http://dx.doi.org/10.1083/jcb.200807006 Text en © 2008 Reber et al. This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.jcb.org/misc/terms.shtml). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 3.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/3.0/).
spellingShingle Research Articles
Reber, Simone
Over, Sabine
Kronja, Iva
Gruss, Oliver J.
CaM kinase II initiates meiotic spindle depolymerization independently of APC/C activation
title CaM kinase II initiates meiotic spindle depolymerization independently of APC/C activation
title_full CaM kinase II initiates meiotic spindle depolymerization independently of APC/C activation
title_fullStr CaM kinase II initiates meiotic spindle depolymerization independently of APC/C activation
title_full_unstemmed CaM kinase II initiates meiotic spindle depolymerization independently of APC/C activation
title_short CaM kinase II initiates meiotic spindle depolymerization independently of APC/C activation
title_sort cam kinase ii initiates meiotic spindle depolymerization independently of apc/c activation
topic Research Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2600749/
https://www.ncbi.nlm.nih.gov/pubmed/19064669
http://dx.doi.org/10.1083/jcb.200807006
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