scholarly journals The CACC Box and Myocyte Enhancer Factor-2 Sites within the Myosin Light Chain 2 Slow Promoter Cooperate in Regulating Nerve-specific Transcription in Skeletal Muscle

1999 ◽  
Vol 274 (17) ◽  
pp. 12095-12102 ◽  
Author(s):  
Karyn Esser ◽  
Tricia Nelson ◽  
Valerie Lupa-Kimball ◽  
Eric Blough
Keyword(s):  
Skeletal Muscle ◽  
Light Chain ◽  
Myosin Light Chain ◽  
Myocyte Enhancer Factor 2 ◽  
Myocyte Enhancer Factor ◽  
Myosin Light Chain 2 ◽  
Enhancer Factor

Amino acid sequence of rabbit ventricular myosin light chain-2: Identity with the slow skeletal muscle isoform

1986 ◽  
Vol 6 (7) ◽  
pp. 655-661 ◽  
Author(s):  
John H. Collins ◽  
Janet L. Theibert ◽  
Luciano Dalla Libera
Keyword(s):  
Skeletal Muscle ◽  
Amino Acid ◽  
Light Chain ◽  
Myosin Light Chain ◽  
Strong Support ◽  
Sequence Information ◽  
Myosin Isoforms ◽  
Amino Acid Residues ◽  
Myosin Light Chain 2 ◽  
Muscle Types

Many studies have established a correlation of differences in the activities of various muscle types with differences in the expression of myosin isoforms. In this paper we report the sequence determination of myosin light chain-2 from rabbit slow skeletal (LC2s) and ventricular (LC2v) nmscles. We sequenced tryptic peptides from LC2v which account for all except a few terminal amino acid residues. The major part (87 residues) of the rabbit LC2s sequence, obtained from tryptic and cyanogen bromide (CNBr) peptides, was found to be identical to rabbit LC2v. Our results provide the first sequence information on LC2s from any species, and lend strong support to the hypothesis that LC2s and LC2v are identical. Comparisons of rabbit LC2v and LC2s with rabbit LC2f (from fast skeletal muscle), and also with chicken LC2f and LC2v, show clearly that LC2s and LC2v from mammalian and avian species are more closely related to each other than they are to LC2f isoforms from the same species.

scholarly journals Direct Interaction between Myocyte Enhancer Factor 2 (MEF2) and Protein Phosphatase 1α Represses MEF2-Dependent Gene Expression

2009 ◽  
Vol 29 (12) ◽  
pp. 3355-3366 ◽  
Author(s):  
R. L. S. Perry ◽  
C. Yang ◽  
N. Soora ◽  
J. Salma ◽  
M. Marback ◽  
...  
Keyword(s):  
Gene Expression ◽  
Skeletal Muscle ◽  
Protein Interactions ◽  
Protein Phosphatase ◽  
Hippocampal Neurons ◽  
Neuronal Cell ◽  
Direct Interaction ◽  
Myocyte Enhancer Factor 2 ◽  
Myocyte Enhancer Factor ◽  
Enhancer Factor

ABSTRACT The myocyte enhancer factor 2 (MEF2) transcription factors play important roles in neuronal, cardiac, and skeletal muscle tissues. MEF2 serves as a nuclear sensor, integrating signals from several signaling cascades through protein-protein interactions with kinases, chromatin remodeling factors, and other transcriptional regulators. Here, we report a novel interaction between the catalytic subunit of protein phosphatase 1α (PP1α) and MEF2. Interaction occurs within the nucleus, and binding of PP1α to MEF2 potently represses MEF2-dependent transcription. The interaction utilizes uncharacterized domains in both PP1α and MEF2, and PP1α phosphatase activity is not obligatory for MEF2 repression. Moreover, a MEF2-PP1α regulatory complex leads to nuclear retention and recruitment of histone deacetylase 4 to MEF2 transcription complexes. PP1α-mediated repression of MEF2 overrides the positive influence of calcineurin signaling, suggesting PP1α exerts a dominant level of control over MEF2 function. Indeed, PP1α-mediated repression of MEF2 function interferes with the prosurvival effect of MEF2 in primary hippocampal neurons. The PP1α-MEF2 interaction constitutes a potent locus of control for MEF2-dependent gene expression, having potentially important implications for neuronal cell survival, cardiac remodeling in disease, and terminal differentiation of vascular, cardiac, and skeletal muscle.

scholarly journals Molecular cloning of up-regulated cytoskeletal genes from regenerating skeletal muscle: potential role of myocyte enhancer factor 2 proteins in the activation of muscle-regeneration-associated genes

1997 ◽  
Vol 325 (1) ◽  
pp. 87-93 ◽  
Author(s):  
Waleed M. AKKILA ◽  
Rebecca L. CHAMBERS ◽  
Olga I. ORNATSKY ◽  
John C. McDERMOTT
Keyword(s):  
Skeletal Muscle ◽  
Transcriptional Activation ◽  
Regulatory Protein ◽  
Cdna Clones ◽  
Myocyte Enhancer Factor 2 ◽  
Consensus Binding Site ◽  
Mobility Shift ◽  
Adult Skeletal Muscle ◽  
Myocyte Enhancer Factor ◽  
Enhancer Factor

A subtractive hybridization and cloning strategy was used to identify genes that are up-regulated in regenerating compared with normal skeletal muscle. The gastrocnemius muscle of CD1 mice was injected with a myotoxic agent (BaCl2). A cDNA library was constructed from the regenerating muscle, and was screened with subtracted probes enriched in genes up-regulated during regeneration. Cofilin and vimentin cDNA clones were isolated. Both cofilin and vimentin were demonstrated to be overexpressed in regenerating compared with non-regenerating muscle (17-fold and 19-fold induction respectively). Cofilin and vimentin mRNAs also exhibited an increased expression in C2C12 myoblasts and a decreased expression in differentiated myotubes. Analysis of the regeneration-induced vimentin enhancer/promoter region revealed a consensus binding site for the myocyte enhancer factor 2 (MEF2) transcription factors. Electrophoretic mobility-shift assays and in vivo reporter assays revealed that MEF2 DNA-binding activity and transcriptional activation are increased in regenerating skeletal muscle, indicating that they may play a role in the activation of muscle genes during regeneration. These data suggest that both cofilin (an actin-regulatory protein) and vimentin (an intermediate filament) may be key components of the cytoskeletal reorganization that mediates muscle cell development and adult skeletal-muscle repair.

Invited Review: Regulation of skeletal muscle GLUT-4 expression by exercise

2002 ◽  
Vol 93 (2) ◽  
pp. 782-787 ◽  
Author(s):  
G. Lynis Dohm
Keyword(s):  
Skeletal Muscle ◽  
Transcriptional Control ◽  
Therapeutic Strategies ◽  
Glucose Disposal ◽  
Research Needs ◽  
Maximal Rate ◽  
Myocyte Enhancer Factor 2 ◽  
Glut 4 ◽  
Myocyte Enhancer Factor ◽  
Enhancer Factor

The amount of GLUT-4 protein is a primary factor in determining the maximal rate of glucose transport into skeletal muscle. Therefore, it is important that we understand how exercise regulates GLUT-4 expression so that therapeutic strategies can be designed to increase muscle glucose disposal as a treatment for diabetes. Muscle contraction increases the rates of GLUT-4 transcription and translation. Transcriptional control likely requires at least two DNA binding proteins, myocyte enhancer factor-2 and GLUT-4 enhancer factor, which bind to the promoter. Increased GLUT-4 expression may be mediated by the enzyme AMP-activated kinase, which is activated during exercise and has been demonstrated to increase GLUT-4 transcription. Further research needs to be done to investigate whether AMP-activated kinase activates myocyte enhancer factor-2 and GLUT-4 enhancer factor to increase transcription of the GLUT-4 gene.

scholarly journals Tissue-specific transcription of the cardiac myosin light-chain 2 gene is regulated by an upstream repressor element.

1991 ◽  
Vol 11 (3) ◽  
pp. 1676-1685 ◽  
Author(s):  
R A Shen ◽  
S K Goswami ◽  
E Mascareno ◽  
A Kumar ◽  
M A Siddiqui
Keyword(s):  
Gene Expression ◽  
Skeletal Muscle ◽  
Cardiac Muscle ◽  
Light Chain ◽  
Myosin Light Chain ◽  
Muscle Cells ◽  
Skeletal Muscle Cells ◽  
Tissue Specific ◽  
Myosin Light Chain 2 ◽  
Functional Components

Physiological expression of the cardiac muscle myosin light-chain 2 (MLC-2) gene in chickens is restricted to cardiac muscle tissue only, at least during the late embryonic to adult stages of development. The mechanism by which cardiac MLC-2 gene expression is repressed in differentiated noncardiac muscle tissues is unknown. Using sequential 5'-deletion mutants of the cardiac MLC-2 promoter introduced into primary skeletal muscle cells in culture, we have demonstrated that a 89-bp region, designated the cardiac-specific sequence (CSS), is essential for repression of cardiac MLC-2 expression in skeletal muscle. Removal of the CSS sequence alone allows transcription in skeletal muscle cells without affecting the transcriptional activity of the promoter in cardiac muscle cells. DNase I footprinting and gel shift assays indicate that protein binding to sequences in the CSS domain occurs readily in nuclear extracts obtained from skeletal muscle but not in extracts isolated under identical conditions from cardiac muscle. Thus, it appears that a negative regulatory mechanism accounts for the lack of expression of the cardiac MLC-2 gene in skeletal muscle and that the CSS element and its binding proteins are important functional components of the regulatory apparatus which ensures the developmental program for cardiac tissue-specific gene expression.

The expression of the regulatory myosin light chain 2 gene during mouse embryogenesis

Development ◽  
1993 ◽  
Vol 118 (3) ◽  
pp. 919-929 ◽  
Author(s):  
A. Faerman ◽  
M. Shani
Keyword(s):  
Skeletal Muscle ◽  
Light Chain ◽  
Myosin Light Chain ◽  
Fast Skeletal Muscle ◽  
Mouse Embryogenesis ◽  
Skeletal Muscle Myosin ◽  
Adult Mice ◽  
Regulatory Myosin Light Chain ◽  
Myosin Light Chain 2 ◽  
Muscle Groups

The fast skeletal muscle myosin light chain 2 (MLC2) gene is expressed specifically in skeletal muscles of newborn and adult mice, and has no detectable sequence homology with any of the other MLC genes including the slow cardiac MLC2 gene. The expression of the fast skeletal muscle MLC2 gene during early mouse embryogenesis was studied by in situ hybridization. Serial sections of embryos from 8.5 to 12.5 days post coitum (d.p.c.) were hybridized to MLC2 cRNA and to probes for the myogenic regulatory genes MyoD1 and myogenin. The results revealed different temporal and spatial patterns of hybridization for different muscle groups. MLC2 transcripts were first detected 9.5 d.p.c. in the myotomal regions of rostral somites, already expressing myogenin. Surprisingly, at the same stage, a weak MLC2 signal was also detected in the cardiomyocytes. The cardiac expression was transient and could not be detected at later stages while the myotomal signal persisted and spread to the more caudal somites, very similar to the expression of myogenin. Beginning from 10.5 d.p.c., several extramyotomal premuscle cells masses have been demarcated by MyoD1 expression. MLC2 transcripts were detected in only one of these cell masses. Although, transcripts of myogenin were detected in all these cell masses, the number of expressing cells was significantly lower than that observed for MyoD1. By 11.5 d.p.c., all three hybridization signals colocalized in most extramyotomal muscle-forming regions, with the exception of the diaphragm and the hindlimb buds, where only few cells expressed MLC2 and more cells expressed MyoD1 than myogenin. At 12.5 d.p.c., all three studied genes displayed a similar spatial pattern of expression in most muscle-forming regions. However, in some muscles, the MyoD1 signal spread over more cells compared to myogenin or MLC2. Our results are consistent with the suggestion that multiple myogenic programs exist for myoblasts differentiating in the myotome and extramyotomal regions.

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