%0 Journal Article %J Biochim Biophys Acta Mol Cell ResBiochim Biophys Acta Mol Cell ResBiochim Biophys Acta Mol Cell Res %D 2017 %T Muscle Lim Protein and myosin binding protein C form a complex regulating muscle differentiation %A Arvanitis, DA %A Vafiadaki, E. %A Papalouka, V. %A Sanoudou, D. %K Adenosine Triphosphatases/genetics %K Animals %K Carrier Proteins/*genetics/metabolism %K Cell Differentiation/*genetics %K Gene Expression Regulation, Developmental %K Humans %K LIM Domain Proteins/*genetics/metabolism %K Muscle Development/*genetics %K Muscle Proteins/*genetics/metabolism %K Muscle, Striated/growth & development/metabolism %K Muscular Diseases/genetics/pathology %K Myoblasts/metabolism %K Phosphorylation %K Sarcomeres/genetics %X Muscle Lim Protein (MLP) is a protein with multiple functional roles in striated muscle physiology and pathophysiology. Herein, we demonstrate that MLP directly binds to slow, fast, and cardiac myosin-binding protein C (MyBP-C) during myogenesis, as shown by yeast two-hybrid and a range of protein-protein interaction assays. The minimal interacting domains involve MLP inter-LIM and MyBP-C [C4]. The interaction is sensitive to cytosolic Ca(2+) concentrations changes and to MyBP-C phosphorylation by PKA or CaMKII. Confocal microscopy of differentiating myoblasts showed MLP and MyBP-C colocalization during myoblast differentiation. Suppression of the complex formation with recombinant MyBP-C [C4] peptide overexpression, inhibited myoblast differentiation by 65%. Suppression of both MLP and MyBP-C expression in myoblasts by siRNA revealed negative synergistic effects on differentiation. The MLP/MyBP-C complex modulates the actin activated myosin II ATPase activity in vitro, which could interfere with sarcomerogenesis and myofilaments assembly during differentiation. Our data demonstrate a critical role of the MLP/MyBP-C complex during early myoblast differentiation. Its absence in muscles with mutations or aberrant expression of MLP or MyBP-C could be directly implicated in the development of cardiac and skeletal myopathies. %B Biochim Biophys Acta Mol Cell ResBiochim Biophys Acta Mol Cell ResBiochim Biophys Acta Mol Cell Res %V 1864 %P 2308-2321 %8 Dec %@ 0167-4889 (Print)0167-4889 (Linking) %G eng %M 28867610 %! Biochimica et biophysica acta. Molecular cell researchBiochimica et biophysica acta. Molecular cell research