title: MEF2C DNA-binding activity is inhibited through its interaction with the regulatory protein Ki-1/57.
abstract: Myocyte enhancer factor (MEF2) are MADS box transcription factors that play important roles in the regulation of myogenesis and morphogenesis of muscle cells. MEF2 proteins are activated by mechanical overload in the heart. In this study, we found the interaction of MEF2C with the regulatory protein Ki-1/57 using yeast two-hybrid system. This interaction was confirmed by GST-pull down assay in vitro and by co-immunoprecipitation in vivo. This interaction is also dependent on pressure overload in the heart. Co-imunoprecipitation assay with anti-MEF2 and anti-Ki-1/57 antibodies demonstrated a basal association between these proteins in the left ventricles of control rats. Pressure overload caused a reduction in this association. Ki-1/57 co-localizes with MEF2 in the nucleus of myocytes of control rats. However, after submitting the animals to pressure overload Ki-1/57 leaves the nucleus thereby decreasing this co-localization. Ki-1/57 also exerts an inhibitory effect upon MEF2C DNA binding activity. These results suggest that Ki-1/57 is a new interacting partner of MEF2 protein and may be involved in the regulation of MEF2 at the onset of hypertrophy.
authors.affiliation: Departamento de Clínica Médica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Cidade Universitária Zefferino Vaz, SP, Brazil.
authors.forename: Claudia Bandeira
authors.initials: CB
authors.lastname: Kobarg
authors.forename: Jörg
authors.initials: J
authors.lastname: Kobarg
authors.forename: Daniella P
authors.initials: DP
authors.lastname: Crosara-Alberto
authors.forename: Thaís Holtz
authors.initials: TH
authors.lastname: Theizen
authors.forename: Kleber Gomes
authors.initials: KG
authors.lastname: Franchini
mesh_terms: D048948:14-3-3 Proteins / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D004247:DNA / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D024202:Electrophoretic Mobility Shift Assay; D004926:Escherichia coli / Q000235:genetics; D005455:Fluorescent Antibody Technique; D005456:Fluorescent Dyes; D015723:Gene Library; D005982:Glutathione Transferase / Q000378:metabolism; D006352:Heart Ventricles / Q000166:cytology; D006801:Humans; D006834:Hydrazines; D007150:Immunohistochemistry; D026161:MADS Domain Proteins; D064326:MEF2 Transcription Factors; D008297:Male; D018613:Microscopy, Confocal; D008969:Molecular Sequence Data; D032383:Myocytes, Cardiac / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D018006:Myogenic Regulatory Factors / Q000378:metabolism*; D011233:Precipitin Tests; D051381:Rats; D017208:Rats, Wistar; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid; D013347:Subcellular Fractions / Q000378:metabolism; D014157:Transcription Factors / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D020798:Two-Hybrid System Techniques
chemical_list: D048948:14-3-3 Proteins; C417561:Alexa 488 hydrazide; D004268:DNA-Binding Proteins; D005456:Fluorescent Dyes; C500946:HABP4 protein, human; D006834:Hydrazines; D026161:MADS Domain Proteins; D064326:MEF2 Transcription Factors; C578040:MEF2C protein, human; D018006:Myogenic Regulatory Factors; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D004247:DNA; D005982:Glutathione Transferase