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Puralpha and Purbeta collaborate with Sp3 to negatively regulate beta-myosin heavy chain gene expression during skeletal muscle inactivity.
- Source :
-
Molecular and cellular biology [Mol Cell Biol] 2007 Feb; Vol. 27 (4), pp. 1531-43. Date of Electronic Publication: 2006 Dec 04. - Publication Year :
- 2007
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Abstract
- Adult skeletal muscle retains the capability of transcriptional reprogramming. This attribute is readily observable in the non-weight-bearing (NWB) soleus muscle, which undergoes a slow-to-fast fiber type transition concurrent with decreased beta-myosin heavy chain (betaMyHC) gene expression. Our previous work showed that Sp3 contributes to decreased betaMyHC gene expression under NWB conditions. In this study, we demonstrate that physical and functional interactions between Sp3, Puralpha, and Purbeta proteins mediate repression of betaMyHC expression under NWB conditions. Binding of Puralpha or Purbeta to the single-stranded betaMyHC distal negative regulatory element-sense strand (dbetaNRE-S) element is markedly increased under NWB conditions. Ectopic expression of Puralpha and Purbeta decreased betaMyHC reporter gene expression, while mutation of the dbetaNRE-S element increased expression in C2C12 myotubes. The dbetaNRE-S element conferred Pur-dependent decreased expression on a minimal thymidine kinase promoter. Short interfering RNA sequences specific for Sp3 or for Puralpha and Purbeta decreased endogenous Sp3 and Pur protein levels and increased betaMyHC reporter gene expression in C2C12 myotubes. Immunoprecipitation assays revealed an association between endogenous Puralpha, Purbeta, and Sp3, while chromatin immunoprecipitation assays demonstrated Puralpha, Purbeta, and Sp3 binding to the betaMyHC proximal promoter region harboring the dbetaNRE-S and C-rich elements in vivo. These data demonstrate that Pur proteins collaborate with Sp3 to regulate a transcriptional program that enables muscle cells to remodel their phenotype.
- Subjects :
- Animals
Base Sequence
Cell Extracts
Chromatin Immunoprecipitation
Electrophoretic Mobility Shift Assay
Genes, Reporter
Humans
Mice
Molecular Sequence Data
Muscle Fibers, Skeletal cytology
Muscle, Skeletal cytology
Mutation genetics
Nucleotides metabolism
Promoter Regions, Genetic genetics
Protein Binding
RNA, Small Interfering metabolism
Rats
Weight-Bearing
DNA-Binding Proteins metabolism
Down-Regulation
Muscle, Skeletal metabolism
Myosin Heavy Chains genetics
Nerve Tissue Proteins metabolism
Sp3 Transcription Factor metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 0270-7306
- Volume :
- 27
- Issue :
- 4
- Database :
- MEDLINE
- Journal :
- Molecular and cellular biology
- Publication Type :
- Academic Journal
- Accession number :
- 17145772
- Full Text :
- https://doi.org/10.1128/MCB.00629-06