title: Probing telomeric G-quadruplex DNA structures in cells with in vitro generated single-chain antibody fragments.
abstract: Guanine-rich sequences have been shown to readily form parallel or antiparallel G-quadruplex DNA structures in vitro. All telomeric repeat sequences contain stretches of guanine residues that can form quadruplex structures. In order to demonstrate the occurrence of the quadruplex structure in vivo, we generated by ribosome display, scFv antibodies specific for quadruplex DNA structures formed by the telomeric sequence of the ciliate Stylonychia. The macronucleus of this hypotrichous ciliate contains 10(8) telomere-capped nanochromosomes and was stained with the antibody recognizing the antiparallel G-quadruplex DNA in indirect immuno-fluorescence assays. This antibody was also used as a specific probe to study the interaction of the telomere end-binding proteins with the G-quadruplex during different stages of the cell cycle.
authors.affiliation: Institute for Molecular Biology and Biophysics, ETH Zürich, Zürich, Switzerland.
authors.forename: Christiane
authors.initials: C
authors.lastname: Schaffitzel
authors.forename: Jan
authors.initials: J
authors.lastname: Postberg
authors.forename: Katrin
authors.initials: K
authors.lastname: Paeschke
authors.forename: Hans J
authors.initials: HJ
authors.lastname: Lipps
mesh_terms: D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry*; D024202:Electrophoretic Mobility Shift Assay; D054856:G-Quadruplexes; D006801:Humans; D007128:Immunoglobulin Fragments / Q000235:genetics / Q000276:immunology; D007135:Immunoglobulin Variable Region / Q000235:genetics / Q000276:immunology; D017404:In Situ Hybridization, Fluorescence; D066298:In Vitro Techniques; D011863:Radioimmunoassay; D057127:Single-Chain Antibodies / Q000235:genetics / Q000276:immunology*; D016615:Telomere / Q000737:chemistry*
chemical_list: D007128:Immunoglobulin Fragments; D007135:Immunoglobulin Variable Region; D057127:Single-Chain Antibodies; C055966:immunoglobulin Fv; D004247:DNA