title: 17β-Estradiol-induced interaction of ERα with NPPA regulates gene expression in cardiomyocytes.
abstract: OBJECTIVE
  17β-Oestradiol (E2) and its receptors (ERα and ERβ) are important regulators of physiological and pathological processes in the cardiovascular system. ER act in concert with other regulatory factors mediating oestrogenic effects. However, the underlying mechanisms modulating ER transcriptional activity are not fully elucidated. To gain better understanding of E2-induced ERα action in the human heart, we aimed to identify and functionally analyse interaction partners of ERα.
  
  
  RESULTS
  Using yeast two-hybrid assays with a human heart cDNA library, we identified atrial natriuretic peptide precursor A (NPPA), a well-known cardiac hypertrophy marker, as a novel ERα interaction partner interacting in an E2-dependent manner. Mutation analyses and immunofluorescence data indicated that the LXXLL motif within NPPA is necessary for its E2-induced interaction with ERα, its action as a co-repressor of ERα, and its translocation into the nucleus of human and rat cardiomyocytes. Expression analysis and chromatin immunoprecipitation assays in a human left ventricular cardiomyocyte cell line, AC16, showed that NPPA interacts with E2/ERα, suppressing the transcriptional activity of ERα on E2-target genes, such as NPPA, connexin43, αactinin-2, nuclear factor of activated T-cells, and collagens I and III.
  
  
  CONCLUSIONS
  We characterize for the first time an E2-regulated interaction of NPPA with ERα in cardiomyocytes, that may be crucial in physiological and/or pathological cardiac processes, thereby representing a potential therapeutic target.
authors.affiliation: Institute of Gender in Medicine, Center for Cardiovascular Research, Charité-Universitaetsmedizin Berlin, Hessische Str. 3-4 10115, Berlin, Germany. s.mahmoodzadeh@charite.de
authors.forename: Shokoufeh
authors.initials: S
authors.lastname: Mahmoodzadeh
authors.forename: Thi Hang
authors.initials: TH
authors.lastname: Pham
authors.forename: Arne
authors.initials: A
authors.lastname: Kuehne
authors.forename: Britta
authors.initials: B
authors.lastname: Fielitz
authors.forename: Elke
authors.initials: E
authors.lastname: Dworatzek
authors.forename: Georgios
authors.initials: G
authors.lastname: Kararigas
authors.forename: George
authors.initials: G
authors.lastname: Petrov
authors.forename: Mercy M
authors.initials: MM
authors.lastname: Davidson
authors.forename: Vera
authors.initials: V
authors.lastname: Regitz-Zagrosek
mesh_terms: D021581:Active Transport, Cell Nucleus; D000818:Animals; D000831:Animals, Newborn; D009320:Atrial Natriuretic Factor / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D047369:Chromatin Immunoprecipitation; D004958:Estradiol / Q000494:pharmacology*; D047628:Estrogen Receptor alpha / Q000819:agonists* / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D005260:Female; D005455:Fluorescent Antibody Technique; D005786:Gene Expression Regulation; D006801:Humans; D051379:Mice; D018345:Mice, Knockout; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D032383:Myocytes, Cardiac / Q000187:drug effects* / Q000378:metabolism; D020098:Natriuretic Peptide, C-Type / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D025941:Protein Interaction Mapping; D011498:Protein Precursors / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D014158:Transcription, Genetic; D014162:Transfection; D020798:Two-Hybrid System Techniques
chemical_list: C506487:ESR1 protein, human; D047628:Estrogen Receptor alpha; C472955:NPPA protein, human; C431578:Nppa protein, mouse; D011498:Protein Precursors; D012333:RNA, Messenger; C472610:atrial natriuretic peptide, rat; D020098:Natriuretic Peptide, C-Type; D004958:Estradiol; D009320:Atrial Natriuretic Factor