Abstract
To identify sequences responsible for the muscle-specific expression of the rat GLUT4/muscle-fat gene, we examined the transcriptional regulation of this gene in the differentiating murine C2C12 skeletal muscle cell line. Differentiated myofibers displayed a 4-5-fold increase in GLUT4 mRNA compared with undifferentiated myoblasts which paralleled the conversion from non-muscle β-actin mRNA to muscle-specific α-actin mRNA expression. Transient transfection of progressive 5′ and 3′ deletions of the GLUT4 5′-flanking DNA identified a 281-base pair region located between -517 and -237 relative to the transcription start site which conferred myotube-specific expression. This region increased reporter activity in the context of the GLUT4 minimal promoter in an orientation-independent manner and, in addition, onto the heterologous thymidine kinase promoter. Myotube-specific expression of both GLUT4 reporter constructs and the endogenous mouse GLUT4 mRNA was also observed to be thyroid hormone-dependent. Further, cotransfection of reporter constructs containing the 281-base pair GLUT4 differentiation-specific enhancer with the thyroid hormone receptor specifically increased luciferase activity in myotubes approximately 12-fold. Thus, these data demonstrate the presence of a proximal skeletal muscle-specific activation domain that is necessary for both myotube-specific GLUT4 expression and thyroid hormone responsiveness.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 21021-21027 |
| Number of pages | 7 |
| Journal | Journal of Biological Chemistry |
| Volume | 268 |
| Issue number | 28 |
| State | Published - Oct 5 1993 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Biochemistry
Cite this
Identification of a skeletal muscle-specific regulatory domain in the rat GLUT4/muscle-fat gene. / Richardson, Jeanne M.; Pessin, Jeffrey E.
In: Journal of Biological Chemistry, Vol. 268, No. 28, 05.10.1993, p. 21021-21027.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Identification of a skeletal muscle-specific regulatory domain in the rat GLUT4/muscle-fat gene
AU - Richardson, Jeanne M.
AU - Pessin, Jeffrey E.
PY - 1993/10/5
Y1 - 1993/10/5
N2 - To identify sequences responsible for the muscle-specific expression of the rat GLUT4/muscle-fat gene, we examined the transcriptional regulation of this gene in the differentiating murine C2C12 skeletal muscle cell line. Differentiated myofibers displayed a 4-5-fold increase in GLUT4 mRNA compared with undifferentiated myoblasts which paralleled the conversion from non-muscle β-actin mRNA to muscle-specific α-actin mRNA expression. Transient transfection of progressive 5′ and 3′ deletions of the GLUT4 5′-flanking DNA identified a 281-base pair region located between -517 and -237 relative to the transcription start site which conferred myotube-specific expression. This region increased reporter activity in the context of the GLUT4 minimal promoter in an orientation-independent manner and, in addition, onto the heterologous thymidine kinase promoter. Myotube-specific expression of both GLUT4 reporter constructs and the endogenous mouse GLUT4 mRNA was also observed to be thyroid hormone-dependent. Further, cotransfection of reporter constructs containing the 281-base pair GLUT4 differentiation-specific enhancer with the thyroid hormone receptor specifically increased luciferase activity in myotubes approximately 12-fold. Thus, these data demonstrate the presence of a proximal skeletal muscle-specific activation domain that is necessary for both myotube-specific GLUT4 expression and thyroid hormone responsiveness.
AB - To identify sequences responsible for the muscle-specific expression of the rat GLUT4/muscle-fat gene, we examined the transcriptional regulation of this gene in the differentiating murine C2C12 skeletal muscle cell line. Differentiated myofibers displayed a 4-5-fold increase in GLUT4 mRNA compared with undifferentiated myoblasts which paralleled the conversion from non-muscle β-actin mRNA to muscle-specific α-actin mRNA expression. Transient transfection of progressive 5′ and 3′ deletions of the GLUT4 5′-flanking DNA identified a 281-base pair region located between -517 and -237 relative to the transcription start site which conferred myotube-specific expression. This region increased reporter activity in the context of the GLUT4 minimal promoter in an orientation-independent manner and, in addition, onto the heterologous thymidine kinase promoter. Myotube-specific expression of both GLUT4 reporter constructs and the endogenous mouse GLUT4 mRNA was also observed to be thyroid hormone-dependent. Further, cotransfection of reporter constructs containing the 281-base pair GLUT4 differentiation-specific enhancer with the thyroid hormone receptor specifically increased luciferase activity in myotubes approximately 12-fold. Thus, these data demonstrate the presence of a proximal skeletal muscle-specific activation domain that is necessary for both myotube-specific GLUT4 expression and thyroid hormone responsiveness.
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M3 - Article
VL - 268
SP - 21021
EP - 21027
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 28
ER -