title: Cyclin B Translation Depends on mTOR Activity after Fertilization in Sea Urchin Embryos.
abstract: The cyclin B/CDK1 complex is a key regulator of mitotic entry. Using PP242, a specific ATP-competitive inhibitor of mTOR kinase, we provide evidence that the mTOR signalling pathway controls cyclin B mRNA translation following fertilization in Sphaerechinus granularis and Paracentrotus lividus. We show that PP242 inhibits the degradation of the cap-dependent translation repressor 4E-BP (eukaryotic initiation factor 4E-Binding Protein). PP242 inhibits global protein synthesis, delays cyclin B accumulation, cyclin B/CDK1 complex activation and consequently entry into the mitotic phase of the cell cycle triggered by fertilization. PP242 inhibits cyclin B mRNA recruitment into active polysomes triggered by fertilization. An amount of cyclin B mRNA present in active polysomes appears to be insensitive to PP242 treatment. Taken together, our results suggest that, following sea urchin egg fertilization, cyclin B mRNA translation is controlled by two independent mechanisms: a PP242-sensitive and an additional PP242-insentitive mechanism.
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, UMR 8227, Integrative Biology of Marine Models, Translation Cell Cycle and Development, Station Biologique de Roscoff, CS 90074, F-29688, Roscoff cedex, France.|CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, 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, CS 90074, F-29688, Roscoff cedex, France.|CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, F-29688, Roscoff cedex, France.
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, CS 90074, F-29688, Roscoff cedex, France.|CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, F-29688, Roscoff cedex, France.
authors.forename: Sandrine
authors.initials: S
authors.lastname: Boulben
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, UMR 8227, Integrative Biology of Marine Models, Translation Cell Cycle and Development, Station Biologique de Roscoff, CS 90074, F-29688, Roscoff cedex, France.|CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, F-29688, Roscoff cedex, France.
authors.forename: Virginie
authors.initials: V
authors.lastname: Glippa
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, UMR 8227, Integrative Biology of Marine Models, Translation Cell Cycle and Development, Station Biologique de Roscoff, CS 90074, F-29688, Roscoff cedex, France.|CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, 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, CS 90074, F-29688, Roscoff cedex, France.|CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, F-29688, Roscoff cedex, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Cormier
mesh_terms: D000818:Animals; D019926:Cyclin B / Q000096:biosynthesis*; D004625:Embryo, Nonmammalian / Q000378:metabolism*; D005306:Fertilization / Q000187:drug effects / Q000502:physiology*; D007211:Indoles / Q000494:pharmacology; D010448:Peptide Initiation Factors / Q000378:metabolism; D011132:Polyribosomes / Q000378:metabolism; D014176:Protein Biosynthesis / Q000187:drug effects / Q000502:physiology*; D011687:Purines / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D012617:Sea Urchins / Q000378:metabolism; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism*
chemical_list: D019926:Cyclin B; D007211:Indoles; D010448:Peptide Initiation Factors; D011687:Purines; D012333:RNA, Messenger; D058570:TOR Serine-Threonine Kinases; C572919:PP242