title: MAPK/ERK activity is required for the successful progression of mitosis in sea urchin embryos.
abstract: Using sea urchin embryos, we demonstrate that the MEK/MAPK/ERK cascade is essential for the proper progression of the cell cycle. Activation of a limited fraction of MAPK/ERK is required between S-phase and M-phase. Neither DNA replication nor CDK1 activation are impacted by the inhibition of this small active MAPK/ERK fraction. Nonetheless, the chromatin and spindle organisations are profoundly altered. Early morphological disorders induced by the absence of MAPK/ERK activation are correlated with an important inhibition of global protein synthesis and modification in the cyclin B accumulation profile. After appearance of morphological disorders, there is an increase in the level of the inhibitor of protein synthesis, 4E-BP, and, ultimately, an activation of the spindle checkpoint. Altogether, our results suggest that MAPK/ERK activity is required for the synthesis of (a) protein(s) implicated in an early step of chromatin /microtubule attachment. If this MAPK/ERK-dependent step is not achieved, the cell activates a new checkpoint mechanism, involving the reappearance of 4E-BP that maintains a low level of protein translation, thus saving cellular energy.
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, UMR 8227, Integrative Biology of Marine Models, Translation Cell Cycle and Development, Station Biologique de Roscoff, CS90074, F-29688 Roscoff cedex, France; CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS90074, F-29688 Roscoff cedex, France. Electronic address: mulner@sb-roscoff.fr.
authors.forename: Odile
authors.initials: O
authors.lastname: Mulner-Lorillon
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, UMR 8227, Integrative Biology of Marine Models, Translation Cell Cycle and Development, Station Biologique de Roscoff, CS90074, F-29688 Roscoff cedex, France; CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS90074, F-29688 Roscoff cedex, France.
authors.forename: Héloïse
authors.initials: H
authors.lastname: Chassé
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, UMR 8227, Integrative Biology of Marine Models, Translation Cell Cycle and Development, Station Biologique de Roscoff, CS90074, F-29688 Roscoff cedex, France; CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS90074, F-29688 Roscoff cedex, France.
authors.forename: Julia
authors.initials: J
authors.lastname: Morales
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, UMR 8227, Integrative Biology of Marine Models, Translation Cell Cycle and Development, Station Biologique de Roscoff, CS90074, F-29688 Roscoff cedex, France; CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS90074, F-29688 Roscoff cedex, France.
authors.forename: Robert
authors.initials: R
authors.lastname: Bellé
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, UMR 8227, Integrative Biology of Marine Models, Translation Cell Cycle and Development, Station Biologique de Roscoff, CS90074, F-29688 Roscoff cedex, France; CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS90074, F-29688 Roscoff cedex, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Cormier
mesh_terms: D000818:Animals; D005075:Biological Evolution; D002070:Butadienes / Q000494:pharmacology; D016203:CDC2 Protein Kinase / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D002843:Chromatin / Q000378:metabolism; D019926:Cyclin B / Q000378:metabolism; D004261:DNA Replication / Q000187:drug effects; D004625:Embryo, Nonmammalian / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology*; D004789:Enzyme Activation / Q000187:drug effects; D005306:Fertilization / Q000187:drug effects; D020935:MAP Kinase Signaling System / Q000187:drug effects; D008870:Microtubules / Q000187:drug effects / Q000378:metabolism; D008938:Mitosis / Q000187:drug effects; D009570:Nitriles / Q000494:pharmacology; D010063:Ovum / Q000166:cytology / Q000187:drug effects; D010766:Phosphorylation / Q000187:drug effects; D014176:Protein Biosynthesis / Q000187:drug effects; D012617:Sea Urchins / Q000166:cytology* / Q000187:drug effects / Q000196:embryology*
chemical_list: D002070:Butadienes; D002352:Carrier Proteins; D002843:Chromatin; D019926:Cyclin B; D009570:Nitriles; C113580:U 0126; D016203:CDC2 Protein Kinase
keywords: Cell cycle checkpoint; Embryonic cell division; MAPK/ERK pathway