The M-phase regulatory phosphatase PP2A-B55δ opposes protein kinase A on Arpp19 to initiate meiotic division.
Nat Commun
; 12(1): 1837, 2021 03 23.
Article
em En
| MEDLINE
| ID: mdl-33758202
ABSTRACT
Oocytes are held in meiotic prophase for prolonged periods until hormonal signals trigger meiotic divisions. Key players of M-phase entry are the opposing Cdk1 kinase and PP2A-B55δ phosphatase. In Xenopus, the protein Arpp19, phosphorylated at serine 67 by Greatwall, plays an essential role in inhibiting PP2A-B55δ, promoting Cdk1 activation. Furthermore, Arpp19 has an earlier role in maintaining the prophase arrest through a second serine (S109) phosphorylated by PKA. Prophase release, induced by progesterone, relies on Arpp19 dephosphorylation at S109, owing to an unknown phosphatase. Here, we identified this phosphatase as PP2A-B55δ. In prophase, PKA and PP2A-B55δ are simultaneously active, suggesting the presence of other important targets for both enzymes. The drop in PKA activity induced by progesterone enables PP2A-B55δ to dephosphorylate S109, unlocking the prophase block. Hence, PP2A-B55δ acts critically on Arpp19 on two distinct sites, opposing PKA and Greatwall to orchestrate the prophase release and M-phase entry.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Oócitos
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Fosfoproteínas
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Proteínas Quinases Dependentes de AMP Cíclico
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Proteínas de Xenopus
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Proteína Fosfatase 2
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Meiose
Limite:
Animals
Idioma:
En
Ano de publicação:
2021
Tipo de documento:
Article