Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.3.1.28 (chloramphenicol acetyltransferase)
 5,100 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The interactions of trans-acting factors with their respective cis-acting elements in the 5' upstream region of the beta myosin heavy chain gene (MyHC) regulate its tissue- and developmental stage-specific expression. The role of three conserved elements, an MCAT or TEF-1 binding site, a C-rich region, and a beta e3 region, in muscle-specific gene expression was analyzed in vivo. Each cis-acting site was ablated in the context of the beta MyHC promoter, fused to the chloramphenicol acetyltransferase reporter gene, and used to generate transgenic mice. In contrast to results obtained in vitro, the data demonstrate that mutating any one of these cis-acting elements does not affect the level or tissue specificity of transgene expression. Sequences upstream of -600 can functionally substitute for any one of these regulatory cassettes and are important both for high levels of expression as well as for controlled muscle specificity. Mutation of any two of the cis-acting elements also does not affect transgene expression. However, simultaneous mutation of the three sites significantly reduces expression, indicating that these conserved sequences do play an important role and that combinatorial interactions underlie the beta MyHC's regulation.
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PMID:In vivo regulation of the mouse beta myosin heavy chain gene. 798 72

The M-CAT motif is a cis-regulatory DNA sequence that is essential for muscle-specific transcription of several genes. Previously, we had shown that both muscle-specific (A1) and ubiquitous (A2) factors bind to an essential M-CAT motif in the myosin heavy chain beta gene and that the ubiquitous factor is transcriptional enhancer factor (TEF)-1. Here we report the isolation of mouse cDNAs encoding two forms (a and b) of a TEF-1-related protein, TEFR1. The TEFR1a cDNA encodes a 427-amino acid protein. The coding region of TEFR1b is identical to 1a in both nucleotide and predicted amino acid sequence except for the absence of 43 amino acids downstream of the TEA DNA-binding domain. Three TEFR1 transcripts (approximately 7, approximately 3.5, and approximately 2 kilobase pairs) are enriched in differentiated skeletal muscle (myotubes) relative to undifferentiated skeletal muscle (myoblasts) and non-muscle cells in culture. In situ hybridization analysis indicated that TEFR1 transcripts are enriched in the skeletal muscle lineage during mouse embryogenesis. Transient expression of fusion proteins of TEFR1 and the yeast GAL4 DNA-binding domain in cell lines activated the expression of chloramphenicol acetyltransferase (CAT) reporter constructs containing GAL4 binding sites, indicating that TEFR1 contains an activation domain. An anti-TEFR1 polyclonal antibody supershifted the muscle-specific M-CAT.A1 factor complex in gel mobility shift assays, suggesting that TEFR1 is a major component of this complex. Our results suggest that TEFR1 might play a role in the embryonic development of skeletal muscle in the mouse.
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PMID:cDNA cloning and characterization of murine transcriptional enhancer factor-1-related protein 1, a transcription factor that binds to the M-CAT motif. 863 87

To examine the role of the beta-myosin heavy chain (betaMyHC) distal muscle CAT (MCAT) element in muscle fiber type-specific expression and mechanical overload (MOV) responsiveness, we conducted transgenic and in vitro experiments. In adult transgenic mice, mutation of the distal MCAT element led to significant reductions in chloramphenicol acetyltransferase (CAT) specific activity measured in control soleus and plantaris muscles when compared with wild type transgene beta293WT but did not abolish MOV-induced CAT specific activity. Electrophoretic mobility shift assay revealed the formation of a specific low migrating nuclear protein complex (LMC) at the betaMyHC MCAT element that was highly enriched only when using either MOV plantaris or control soleus nuclear extract. Scanning mutagenesis of the betaMyHC distal MCAT element revealed that only the nucleotides comprising the core MCAT element were essential for LMC formation. The proteins within the LMC when using either MOV plantaris or control soleus nuclear extracts were antigenically related to nominal transcription enhancer factor 1 (NTEF-1), poly(ADP-ribose) polymerase (PARP), and Max. Only in vitro translated TEF-1 protein bound to the distal MCAT element, suggesting that this multiprotein complex is tethered to the DNA via TEF-1. Protein-protein interaction assays revealed interactions between nominal TEF-1, PARP, and Max. Our studies show that for transgene beta293 the distal MCAT element is not required for MOV responsiveness but suggest that a multiprotein complex likely comprised of nominal TEF-1, PARP, and Max forms at this element to contribute to basal slow fiber expression.
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PMID:Multiprotein complex formation at the beta myosin heavy chain distal muscle CAT element correlates with slow muscle expression but not mechanical overload responsiveness. 1101 Sep 74