Muscle LIM protein, a novel essential regulator of myogenesis, promotes myogenic differentiation.
Muscle LIM protein (MLP) is a novel positive regulator of myogenesis. Its expression and that of its Drosophila homolog DMLP1 are enriched in striated muscle and coincide with myogenic differentiation. In the absence of MLP, induced C2 cells express myogenin but fail to exit from the cell cycle and to differentiate. Over-expression of MLP in C2 myoblasts potentiates myogenic differentiation and reduces its sensitivity to TGF beta. Like MLP, single LIM domain deletion mutants of MLP and nonmuscle LIM-only proteins promote myogenic differentiation. In 3T3 fibroblasts, the same LIM proteins prevent phorbol ester-induced inhibition of DNA replication. These results establish MLP as an essential promoter of myogenesis and suggest that LIM-only proteins act via similar mechanisms to regulate aspects of cell differentiation.
Arber
S
S
Friedrich Miescher Institute, Basel, Switzerland.
Halder
G
G
Caroni
P
P
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002454:Cell Differentiation; D002467:Cell Nucleus / Q000378:metabolism; D003001:Cloning, Molecular; D005786:Gene Expression Regulation; D060588:LIM Domain Proteins; D051379:Mice; D008969:Molecular Sequence Data; D009121:Muscle Denervation; D009124:Muscle Proteins / Q000235:genetics / Q000502:physiology*; D009132:Muscles / Q000166:cytology*; D009687:Nuclear Proteins / Q000378:metabolism; D051381:Rats; D017384:Sequence Deletion; D013329:Structure-Activity Relationship
D060588:LIM Domain Proteins; D009124:Muscle Proteins; D009687:Nuclear Proteins; C090114:cysteine and glycine-rich protein 3