title: Divergence in species and regulatory role of beta -myosin heavy chain proximal promoter muscle-CAT elements.
abstract: We examined the functional role of distinct muscle-CAT (MCAT) elements during non-weight-bearing (NWB) regulation of a wild-type 293-base pair beta-myosin heavy chain (beta MyHC) transgene. Electrophoretic mobility shift assays (EMSA) revealed decreased NTEF-1, poly(ADP-ribose) polymerase, and Max binding at the human distal MCAT element when using NWB soleus vs. control soleus nuclear extract. Compared with the wild-type transgene, expression assays revealed that distal MCAT element mutation decreased basal transgene expression, which was decreased further in response to NWB. EMSA analysis of the human proximal MCAT (pMCAT) element revealed low levels of NTEF-1 binding that did not differ between control and NWB extract, whereas the rat pMCAT element displayed robust NTEF-1 binding that decreased when using NWB soleus extracts. Differences in binding between human and rat pMCAT elements were consistent whether using rat or mouse nuclear extract or in vitro synthesized human TEF-1 proteins. Our results provide the first evidence that 1) different binding properties and likely regulatory functions are served by the human and rat pMCAT elements, and 2) previously unrecognized beta MyHC proximal promoter elements contribute to NWB regulation.
authors.affiliation: Department of Biochemistry, School of Medicine, University of Missouri-Columbia, Columbia, Missouri 65211, USA. tsikar@missouri.edu
authors.forename: Richard W
authors.initials: RW
authors.lastname: Tsika
authors.forename: John
authors.initials: J
authors.lastname: McCarthy
authors.forename: Natalia
authors.initials: N
authors.lastname: Karasseva
authors.forename: Yangsi
authors.initials: Y
authors.lastname: Ou
authors.forename: Gretchen L
authors.initials: GL
authors.lastname: Tsika
mesh_terms: D000818:Animals; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D050976:Basic-Leucine Zipper Transcription Factors; D002467:Cell Nucleus / Q000378:metabolism; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics / Q000378:metabolism*; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D006801:Humans; D051379:Mice; D008822:Mice, Transgenic; D018482:Muscle, Skeletal / Q000033:anatomy & histology / Q000378:metabolism*; D009154:Mutation / Q000502:physiology; D018995:Myosin Heavy Chains / Q000235:genetics* / Q000378:metabolism; D009687:Nuclear Proteins; D009711:Nucleotides / Q000502:physiology; D009929:Organ Size / Q000502:physiology; D011401:Promoter Regions, Genetic / Q000502:physiology*; D051381:Rats; D013045:Species Specificity; D000091262:TEA Domain Transcription Factors; D014157:Transcription Factors / Q000378:metabolism; D024723:Ventricular Myosins / Q000235:genetics* / Q000378:metabolism; D016474:Weight-Bearing / Q000502:physiology
chemical_list: D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D050976:Basic-Leucine Zipper Transcription Factors; D004268:DNA-Binding Proteins; C499330:MAX protein, human; C499329:Max protein, rat; C067850:Myc associated factor X; D009687:Nuclear Proteins; D009711:Nucleotides; D000091262:TEA Domain Transcription Factors; C057182:TEAD1 protein, human; D014157:Transcription Factors; C068422:Max protein, mouse; D004247:DNA; D015500:Chloramphenicol O-Acetyltransferase; D024723:Ventricular Myosins; D018995:Myosin Heavy Chains