title: Transposable elements and G-quadruplexes.
abstract: A significant part of eukaryotic genomes is formed by transposable elements (TEs) containing not only genes but also regulatory sequences. Some of the regulatory sequences located within TEs can form secondary structures like hairpins or three-stranded (triplex DNA) and four-stranded (quadruplex DNA) conformations. This review focuses on recent evidence showing that G-quadruplex-forming sequences in particular are often present in specific parts of TEs in plants and humans. We discuss the potential role of these structures in the TE life cycle as well as the impact of G-quadruplexes on replication, transcription, translation, chromatin status, and recombination. The aim of this review is to emphasize that TEs may serve as vehicles for the genomic spread of G-quadruplexes. These non-canonical DNA structures and their conformational switches may constitute another regulatory system that, together with small and long non-coding RNA molecules and proteins, contribute to the complex cellular network resulting in the large diversity of eukaryotes.
authors.affiliation: Department of Plant Developmental Genetics, Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, Czech Republic. kejnovsk@ibp.cz.
authors.forename: Eduard
authors.initials: E
authors.lastname: Kejnovsky
authors.affiliation: Department of Plant Developmental Genetics, Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, Czech Republic.
authors.forename: Viktor
authors.initials: V
authors.lastname: Tokan
authors.affiliation: Faculty of Informatics, Masaryk University Brno, Brno, Czech Republic.
authors.forename: Matej
authors.initials: M
authors.lastname: Lexa
mesh_terms: D004261:DNA Replication; D004251:DNA Transposable Elements / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000378:metabolism; D054856:G-Quadruplexes; D005786:Gene Expression Regulation; D023281:Genomics; D006801:Humans; D016366:Open Reading Frames; D010944:Plants / Q000235:genetics; D011485:Protein Binding; D012313:RNA / Q000737:chemistry / Q000235:genetics; D012045:Regulatory Sequences, Nucleic Acid; D012091:Repetitive Sequences, Nucleic Acid; D018626:Retroelements / Q000235:genetics*
chemical_list: D004251:DNA Transposable Elements; D004268:DNA-Binding Proteins; D018626:Retroelements; D012313:RNA
keywords: DNA and RNA quadruplexes; G-quadruplexes; LTR retrotransposons; recombination; replication; transcription; transposable elements