1. Role for the pleckstrin homology domain-containing protein CKIP-1 in phosphatidylinositol 3-kinase-regulated muscle differentiation
- Author
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Laure Valdacci, Marie Vandromme, Laurent Schaeffer, Sabine Caussanel, Dominique Baas, Marc Vidal, Evelyne Goillot, Gilbert Brun, Alexias Safi, Deleage, Gilbert, ProdInra, Migration, Unité mixte de recherche biologie moléculaire de la cellule, Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA)-École normale supérieure - Lyon (ENS Lyon), and École normale supérieure de Lyon (ENS de Lyon)-Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Myotubularin ,[SDV]Life Sciences [q-bio] ,Cellular differentiation ,Biology ,[INFO] Computer Science [cs] ,Wortmannin ,Myoblasts ,03 medical and health sciences ,chemistry.chemical_compound ,Mice ,Phosphatidylinositol 3-Kinases ,0302 clinical medicine ,[SDV.BBM] Life Sciences [q-bio]/Biochemistry, Molecular Biology ,Myocyte ,Animals ,[INFO]Computer Science [cs] ,Phosphatidylinositol ,Molecular Biology ,Cell Growth and Development ,Myogenin ,ComputingMilieux_MISCELLANEOUS ,030304 developmental biology ,Cell Nucleus ,0303 health sciences ,Muscles ,Cell Membrane ,Intracellular Signaling Peptides and Proteins ,Cell Differentiation ,Cell Biology ,Molecular biology ,Cell biology ,Protein Structure, Tertiary ,Pleckstrin homology domain ,[SDV] Life Sciences [q-bio] ,chemistry ,030220 oncology & carcinogenesis ,CELLULE MUSCULAIRE ,Carrier Proteins ,C2C12 ,Cell Division - Abstract
In this work, we report the implication of the pleckstrin homology (PH) domain-containing protein CKIP-1 in phosphatidylinositol 3-kinase (PI3-K)-regulated muscle differentiation. CKIP-1 is upregulated during muscle differentiation in C2C12 cells. We show that CKIP-1 binds to phosphatidylinositol 3-phosphate through its PH domain and localizes to the plasma membrane in a PI3-K-dependent manner. Activation of PI3-K by insulin or expression of an active form of PI3-K p110 induces a rapid translocation of CKIP-1 to the plasma membrane. Conversely, expression of the 3-phosphoinositide phosphatase myotubularin or PI3-K inhibition by LY294002, wortmannin, or mutant p85 abolishes CKIP-1 binding to the membrane. Upon induction of differentiation in low-serum medium, CKIP-1 overexpression in C2C12 myoblasts first promotes proliferation and then stimulates the expression of myogenin and cell fusion in a manner reminiscent of the dual positive effect of insulin-like growth factors on muscle cells. Interference with the PI3-K pathway impedes the effect of CKIP-1 on C2C12 cell differentiation. Finally, silencing of CKIP-1 by RNA interference abolishes proliferation and delays myogenin expression. Altogether, these data strongly implicate CKIP-1 as a new component of PI3-K signaling in muscle differentiation.In this work, we report the implication of the pleckstrin homology (PH) domain-containing protein CKIP-1 in phosphatidylinositol 3-kinase (PI3-K)-regulated muscle differentiation. CKIP-1 is upregulated during muscle differentiation in C2C12 cells. We show that CKIP-1 binds to phosphatidylinositol 3-phosphate through its PH domain and localizes to the plasma membrane in a PI3-K-dependent manner. Activation of PI3-K by insulin or expression of an active form of PI3-K p110 induces a rapid translocation of CKIP-1 to the plasma membrane. Conversely, expression of the 3-phosphoinositide phosphatase myotubularin or PI3-K inhibition by LY294002, wortmannin, or mutant p85 abolishes CKIP-1 binding to the membrane. Upon induction of differentiation in low-serum medium, CKIP-1 overexpression in C2C12 myoblasts first promotes proliferation and then stimulates the expression of myogenin and cell fusion in a manner reminiscent of the dual positive effect of insulin-like growth factors on muscle cells. Interference with the PI3-K pathway impedes the effect of CKIP-1 on C2C12 cell differentiation. Finally, silencing of CKIP-1 by RNA interference abolishes proliferation and delays myogenin expression. Altogether, these data strongly implicate CKIP-1 as a new component of PI3-K signaling in muscle differentiation.
- Published
- 2004