Meiosis requires a translational positive loop where CPEB1 ensues its replacement by CPEB4.
EMBO J
; 29(13): 2182-93, 2010 Jul 07.
Article
em En
| MEDLINE
| ID: mdl-20531391
Meiotic progression is driven by the sequential translational activation of maternal messenger RNAs stored in the cytoplasm. This activation is mainly induced by the cytoplasmic elongation of their poly(A) tails, which is mediated by the cytoplasmic polyadenylation element (CPE) present in their 3' untranslated regions. Although polyadenylation in prophase I and metaphase I is mediated by the CPE-binding protein 1 (CPEB1), this protein is degraded during the first meiotic division. Thus, raising the question of how the cytoplasmic polyadenylation required for the second meiotic division is achieved. In this work, we show that CPEB1 generates a positive loop by activating the translation of CPEB4 mRNA, which, in turn, replaces CPEB1 and drives the transition from metaphase I to metaphase II. We further show that CPEB1 and CPEB4 are differentially regulated by phase-specific kinases, generating the need of two sequential CPEB activities to sustain cytoplasmic polyadenylation during all the meiotic phases. Altogether, this work defines a new element in the translational circuit that support an autonomous transition between the two meiotic divisions in the absence of DNA replication.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Oócitos
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Fatores de Transcrição
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Xenopus
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Proteínas de Ligação a RNA
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Proteínas de Xenopus
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Fatores de Poliadenilação e Clivagem de mRNA
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Meiose
Limite:
Animals
Idioma:
En
Ano de publicação:
2010
Tipo de documento:
Article