Role of myocyte-specific enhancer-binding factor (MEF-2) in transcriptional regulation of the alpha-cardiac myosin heavy chain gene.
The intergenic region between the mouse alpha-cardiac myosin heavy chain and beta-myosin heavy chain genes has previously been shown to direct expression of the bacterial chloramphenicol acetyltransferase reporter gene in transgenic mice in a tissue-specific manner. Sequence analyses located a putative myocyte-specific enhancer-binding factor (MEF-2) site situated in the regulatory region of this gene proximal to the start site of transcription. The role of this element in directing the cardiac compartment-specific expression of the transgene was assessed. The polymerase chain reaction was used to perform substitution mutagenesis of the MEF-2 binding site, and lack of MEF-2 binding was confirmed by gel retardation assays. The resultant construct was used to generate transgenic mice. Surprisingly, transgene expression was not down-regulated, but was significantly increased in the hearts of the MEF-2 mutant mice. In addition, cardiac-specific expression of the transgene was perturbed with significant levels of ectopic expression occurring in the aorta.
Adolph
E A
EA
Department of Medicine, University of Cincinnati College of Medicine, Ohio 45267-0575.
Subramaniam
A
A
Cserjesi
P
P
Olson
E N
EN
Robbins
J
J
D000818:Animals; D001483:Base Sequence; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics; D004247:DNA; D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology*; D005786:Gene Expression Regulation; D064326:MEF2 Transcription Factors; D051379:Mice; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009206:Myocardium / Q000378:metabolism*; D018006:Myogenic Regulatory Factors; D009218:Myosins / Q000235:genetics*; D011401:Promoter Regions, Genetic; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*; D014158:Transcription, Genetic
D004268:DNA-Binding Proteins; D064326:MEF2 Transcription Factors; D018006:Myogenic Regulatory Factors; D014157:Transcription Factors; D004247:DNA; D015500:Chloramphenicol O-Acetyltransferase; D009218:Myosins