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Non-proteolytic ubiquitylation counteracts the APC/C-inhibitory function of XErp1.

ABSTRACT: Mature Xenopus oocytes are arrested in meiosis by the activity of XErp1/Emi2, an inhibitor of the ubiquitin-ligase anaphase-promoting complex/cyclosome (APC/C). On fertilization, XErp1 is degraded, resulting in APC/C activation and the consequent degradation of cell-cycle regulators and exit from meiosis. In this study, we show that a modest increase in the activity of the ubiquitin-conjugating enzyme UbcX overrides the meiotic arrest in an APC/C-dependent reaction. Intriguingly, XErp1 remains stable in these conditions. We found that UbcX causes the ubiquitylation of XErp1, followed by its dissociation from the APC/C. Our data support the idea that ubiquitylation regulates the APC/C-inhibitory activity of XErp1.

SUBMITTER: Hormanseder E

PROVIDER: S-EPMC3090011 | biostudies-literature | 2011 May

REPOSITORIES: biostudies-literature

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Non-proteolytic ubiquitylation counteracts the APC/C-inhibitory function of XErp1.

Hörmanseder Eva E Tischer Thomas T Heubes Simone S Stemmann Olaf O Mayer Thomas U TU

EMBO reports 20110311 5

Mature Xenopus oocytes are arrested in meiosis by the activity of XErp1/Emi2, an inhibitor of the ubiquitin-ligase anaphase-promoting complex/cyclosome (APC/C). On fertilization, XErp1 is degraded, resulting in APC/C activation and the consequent degradation of cell-cycle regulators and exit from meiosis. In this study, we show that a modest increase in the activity of the ubiquitin-conjugating enzyme UbcX overrides the meiotic arrest in an APC/C-dependent reaction. Intriguingly, XErp1 remains s ...[more]

PMID: 21399619

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