title: Human Rap1 modulates TRF2 attraction to telomeric DNA.
abstract: More than two decades of genetic research have identified and assigned main biological functions of shelterin proteins that safeguard telomeres. However, a molecular mechanism of how each protein subunit contributes to the protecting function of the whole shelterin complex remains elusive. Human Repressor activator protein 1 (Rap1) forms a multifunctional complex with Telomeric Repeat binding Factor 2 (TRF2). Rap1-TRF2 complex is a critical part of shelterin as it suppresses homology-directed repair in Ku 70/80 heterodimer absence. To understand how Rap1 affects key functions of TRF2, we investigated full-length Rap1 binding to TRF2 and Rap1-TRF2 complex interactions with double-stranded DNA by quantitative biochemical approaches. We observed that Rap1 reduces the overall DNA duplex binding affinity of TRF2 but increases the selectivity of TRF2 to telomeric DNA. Additionally, we observed that Rap1 induces a partial release of TRF2 from DNA duplex. The improved TRF2 selectivity to telomeric DNA is caused by less pronounced electrostatic attractions between TRF2 and DNA in Rap1 presence. Thus, Rap1 prompts more accurate and selective TRF2 recognition of telomeric DNA and TRF2 localization on single/double-strand DNA junctions. These quantitative functional studies contribute to the understanding of the selective recognition of telomeric DNA by the whole shelterin complex.
authors: Chromatin Molecular Complexes, CEITEC and Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno CZ-62500, Czech Republic.
authors: Eliška
authors: E
authors: Janoušková
authors: Chromatin Molecular Complexes, CEITEC and Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno CZ-62500, Czech Republic.
authors: Ivona
authors: I
authors: Nečasová
authors: Chromatin Molecular Complexes, CEITEC and Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno CZ-62500, Czech Republic.
authors: Jana
authors: J
authors: Pavloušková
authors: Chromatin Molecular Complexes, CEITEC and Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno CZ-62500, Czech Republic.
authors: Michal
authors: M
authors: Zimmermann
authors: Chromatin Molecular Complexes, CEITEC and Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno CZ-62500, Czech Republic.
authors: Milan
authors: M
authors: Hluchý
authors: Department of Biology, Faculty of Medicine, Masaryk University, Brno CZ-62500, Czech Republic.
authors: Victoria
authors: V
authors: Marini
authors: Chromatin Molecular Complexes, CEITEC and Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno CZ-62500, Czech Republic.
authors: Monika
authors: M
authors: Nováková
authors: Chromatin Molecular Complexes, CEITEC and Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno CZ-62500, Czech Republic hofr@sci.muni.cz.
authors: Ctirad
authors: C
authors: Hofr
mesh_terms: D001667:Binding, Competitive / Q000187:drug effects; D004247:DNA / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D005454:Fluorescence Polarization; D006801:Humans; D007700:Kinetics; D011485:Protein Binding / Q000187:drug effects; D000089804:Shelterin Complex; D012965:Sodium Chloride / Q000494:pharmacology; D013050:Spectrometry, Fluorescence; D055672:Static Electricity; D020349:Surface Plasmon Resonance; D016615:Telomere / Q000235:genetics / Q000378:metabolism*; D034501:Telomere-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D035341:Telomeric Repeat Binding Protein 2 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D000089804:Shelterin Complex; C504753:TERF2 protein, human; C440809:TERF2IP protein, human; D034501:Telomere-Binding Proteins; D035341:Telomeric Repeat Binding Protein 2; D012965:Sodium Chloride; D004247:DNA