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The utrophin A 5'-untranslated region confers internal ribosome entry site-mediated translational control during regeneration of skeletal muscle fibers.
- Source :
-
The Journal of biological chemistry [J Biol Chem] 2005 Sep 23; Vol. 280 (38), pp. 32997-3005. Date of Electronic Publication: 2005 Aug 01. - Publication Year :
- 2005
-
Abstract
- Utrophin up-regulation in muscle fibers of Duchenne muscular dystrophy patients represents a potential therapeutic strategy. It is thus important to delineate the regulatory events presiding over utrophin in muscle in attempts to develop pharmacological interventions aimed at increasing utrophin expression. A number of studies have now shown that under several experimental conditions, the abundance of utrophin is increased without a corresponding elevation in its mRNA. Here, we examine whether utrophin expression is regulated at the translational level in regenerating muscle fibers. Treatment of mouse tibialis anterior muscles with cardiotoxin to induce muscle degeneration/regeneration led to a large (approximately 14-fold) increase in the levels of utrophin A with a modest change in expression of its transcript (40%). Isolation of the mouse utrophin A 5'-untranslated region (UTR) revealed that it is relatively long with a predicted high degree of secondary structure. In control muscles, the 5'-UTR of utrophin A caused an inhibition upon translation of a reporter protein. Strikingly, this inhibition was removed during regeneration, indicating that expression of utrophin A in regenerating muscles is translationally regulated via its 5'-UTR. Using bicistronic reporter vectors, we observed that this translational effect involves an internal ribosome entry site in the utrophin A 5'-UTR. Thus, internal ribosome entry site-mediated translation of utrophin A can, at least partially, account for the discordant expression of utrophin A protein and transcript in regenerating muscle. These findings provide a novel target for up-regulating levels of utrophin A in Duchenne muscular dystrophy muscle fibers via pharmacological interventions.
- Subjects :
- Animals
Binding Sites
Blotting, Northern
Blotting, Western
Cells, Cultured
Cobra Cardiotoxin Proteins metabolism
Genes, Reporter
Genetic Vectors
Mice
Mice, Inbred C57BL
Microscopy, Fluorescence
Models, Genetic
Muscles metabolism
Plasmids metabolism
Protein Structure, Secondary
RNA metabolism
RNA, Messenger metabolism
Regeneration
Reverse Transcriptase Polymerase Chain Reaction
Up-Regulation
5' Untranslated Regions
Gene Expression Regulation
Muscle Fibers, Skeletal metabolism
Muscle, Skeletal metabolism
Protein Biosynthesis
Ribosomes metabolism
Utrophin chemistry
Utrophin genetics
Subjects
Details
- Language :
- English
- ISSN :
- 0021-9258
- Volume :
- 280
- Issue :
- 38
- Database :
- MEDLINE
- Journal :
- The Journal of biological chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 16061482
- Full Text :
- https://doi.org/10.1074/jbc.M503994200