Control of Emi2 activity and stability through Mos-mediated recruitment of PP2A.
Abstract
Before fertilization, vertebrate eggs are arrested in meiosis II by cytostatic factor
(CSF), which holds the anaphase-promoting complex (APC) in an inactive state. It was
recently reported that Mos, an integral component of CSF, acts in part by promoting
the Rsk-mediated phosphorylation of the APC inhibitor Emi2/Erp1. We report here that
Rsk phosphorylation of Emi2 promotes its interaction with the protein phosphatase
PP2A. Emi2 residues adjacent to the Rsk phosphorylation site were important for PP2A
binding. An Emi2 mutant that retained Rsk phosphorylation but lacked PP2A binding
could not be modulated by Mos. PP2A bound to Emi2 acted on two distinct clusters of
sites phosphorylated by Cdc2, one responsible for modulating its stability during
CSF arrest and one that controls binding to the APC. These findings provide a molecular
mechanism for Mos action in promoting CSF arrest and also define an unusual mechanism,
whereby protein phosphorylation recruits a phosphatase for dephosphorylation of distinct
sites phosphorylated by another kinase.
Type
Journal articleSubject
Amino Acid SequenceAnimals
F-Box Proteins
Humans
Meiosis
Molecular Sequence Data
Ovum
Phosphorylase Phosphatase
Phosphorylation
Proto-Oncogene Proteins c-mos
Ribosomal Protein S6 Kinases
Signal Transduction
Xenopus
Xenopus Proteins
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http://hdl.handle.net/10161/8391Published Version (Please cite this version)
10.1073/pnas.0707537104Publication Info
Freel, CD; Guo, Y; Hansen, DV; Jackson, PK; Kornbluth, S; Tang, W; ... Wu, JQ (2007). Control of Emi2 activity and stability through Mos-mediated recruitment of PP2A. Proc Natl Acad Sci U S A, 104(42). pp. 16564-16569. 10.1073/pnas.0707537104. Retrieved from http://hdl.handle.net/10161/8391.This is constructed from limited available data and may be imprecise. To cite this
article, please review & use the official citation provided by the journal.
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Show full item recordScholars@Duke
Sally A. Kornbluth
Jo Rae Wright University Professor
Our lab studies the regulation of complex cellular processes, including cell cycle
progression and programmed cell death (apoptosis). These tightly orchestrated processes
are critical for appropriate cell proliferation and cell death, and when they go awry
can result in cancer and degenerative disorders. Within these larger fields, we have
focused on understanding the cellular mechanisms that prevent the onset of mitosis
prior to the completion of DNA replication, the process

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