title: Modulation of Estrogen Response Element-Driven Gene Expressions and Cellular Proliferation with Polar Directions by Designer Transcription Regulators.
abstract: Estrogen receptor α (ERα), as a ligand-dependent transcription factor, mediates 17β-estradiol (E2) effects. ERα is a modular protein containing a DNA binding domain (DBD) and transcription activation domains (AD) located at the amino- and carboxyl-termini. The interaction of the E2-activated ERα dimer with estrogen response elements (EREs) of genes constitutes the initial step in the ERE-dependent signaling pathway necessary for alterations of cellular features. We previously constructed monomeric transcription activators, or monotransactivators, assembled from an engineered ERE-binding module (EBM) using the ERα-DBD and constitutively active ADs from other transcription factors. Monotransactivators modulated cell proliferation by activating and repressing ERE-driven gene expressions that simulate responses observed with E2-ERα. We reasoned here that integration of potent heterologous repression domains (RDs) into EBM could generate monotransrepressors that alter ERE-bearing gene expressions and cellular proliferation in directions opposite to those observed with E2-ERα or monotransactivators. Consistent with this, monotransrepressors suppressed reporter gene expressions that emulate the ERE-dependent signaling pathway. Moreover, a model monotransrepressor regulated DNA synthesis, cell cycle progression and proliferation of recombinant adenovirus infected ER-negative cells through decreasing as well as increasing gene expressions with polar directions compared with E2-ERα or monotransactivator. Our results indicate that an 'activator' or a 'repressor' possesses both transcription activating/enhancing and repressing/decreasing abilities within a chromatin context. Offering a protein engineering platform to alter signal pathway-specific gene expressions and cell growth, our approach could also be used for the development of tools for epigenetic modifications and for clinical interventions wherein multigenic de-regulations are an issue.
authors: Department of Biological Sciences, Middle East Technical University, Ankara, 06800, Turkey; Department of Biochemistry & Biophysics, University of Rochester, Rochester, NY, 14619, United States of America.
authors: Mesut
authors: M
authors: Muyan
authors: Department of Biological Sciences, Middle East Technical University, Ankara, 06800, Turkey.
authors: Gizem
authors: G
authors: Güpür
authors: Department of Biological Sciences, Middle East Technical University, Ankara, 06800, Turkey.
authors: Pelin
authors: P
authors: Yaşar
authors: Department of Biological Sciences, Middle East Technical University, Ankara, 06800, Turkey.
authors: Gamze
authors: G
authors: Ayaz
authors: Department of Biological Sciences, Middle East Technical University, Ankara, 06800, Turkey.
authors: Sırma Damla
authors: SD
authors: User
authors: Department of Biological Sciences, Middle East Technical University, Ankara, 06800, Turkey.
authors: Hasan Hüseyin
authors: HH
authors: Kazan
authors: Department of Biochemistry & Biophysics, University of Rochester, Rochester, NY, 14619, United States of America.
authors: Yanfang
authors: Y
authors: Huang
mesh_terms: D002453:Cell Cycle / Q000187:drug effects; D002460:Cell Line; D016764:Cell Polarity / Q000187:drug effects* / Q000502:physiology; D049109:Cell Proliferation / Q000187:drug effects* / Q000502:physiology; D047628:Estrogen Receptor alpha / Q000187:drug effects / Q000502:physiology*; D005786:Gene Expression Regulation / Q000187:drug effects* / Q000502:physiology; D005818:Genetic Engineering / Q000379:methods; D006801:Humans; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics / Q000494:pharmacology*; D015533:Transcriptional Activation / Q000187:drug effects / Q000502:physiology
chemical_list: D047628:Estrogen Receptor alpha; D014157:Transcription Factors