Sprouty-2 overexpression in C2C12 cells confers myogenic differentiation properties in the presence of FGF2.
Myoblast C2C12 cells cultured in the presence of FGF2 actively proliferate and showed a differentiation-defective phenotype compared with cells cultured in low serum or in the presence of insulin. These FGF2 effects are associated with sustained activation of p44/p42-MAPK and lack of activation of AKT. Here we demonstrate that Sprouty-2, a protein involved in the negative feedback of receptor tyrosine kinase signaling, when stably overexpressed in C2C12 cells and in the presence of FGF2 produces growth arrest (precluding the expression of PCNA and the phosphorylation of retinoblastoma and inducing the expression of p21(CIP)) and myogenesis (multinucleated myotubes formation, induction of creatine kinase and expression of myosin heavy chain protein). These events were accompanied by repression of p44/p42-MAPK and activation of AKT. When C2C12 cells were stably transfected with a Sprouty-2 (Y55F) mutant defective in inhibiting p44/p42-MAPK activation by FGF, myoblasts in the presence of FGF continue to grow and completely fail to form myotubes. This work is the first evidence of the contribution of sprouty genes to myogenic differentiation in the presence of FGF2.
Departamento de Bioquimica y Biologia Molecular, Facultad de Farmacia, Universidad Complutense, 28040 Madrid, Spain.
Cristina
C
de Alvaro
Natalia
N
Martinez
Jose M
JM
Rojas
Margarita
M
Lorenzo
D048868:Adaptor Proteins, Signal Transducing; D019943:Amino Acid Substitution; D000818:Animals; D002454:Cell Differentiation / Q000502:physiology*; D002460:Cell Line; D016222:Fibroblast Growth Factor 2 / Q000502:physiology*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D051379:Mice; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D018482:Muscle, Skeletal / Q000502:physiology; D009154:Mutation; D032446:Myoblasts / Q000166:cytology / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases; D011506:Proteins / Q000235:genetics* / Q000378:metabolism*
D048868:Adaptor Proteins, Signal Transducing; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D011506:Proteins; D016222:Fibroblast Growth Factor 2; D017346:Protein Serine-Threonine Kinases; C118389:Spry2 protein, mouse; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3