title: G-quadruplexes: the beginning and end of UTRs.
abstract: Molecular mechanisms that regulate gene expression can occur either before or after transcription. The information for post-transcriptional regulation can lie within the sequence or structure of the RNA transcript and it has been proposed that G-quadruplex nucleic acid sequence motifs may regulate translation as well as transcription. Here, we have explored the incidence of G-quadruplex motifs in and around the untranslated regions (UTRs) of mRNA. We observed a significant strand asymmetry, consistent with a general depletion of G-quadruplex-forming RNA. We also observed a positional bias in two distinct regions, each suggestive of a specific function. We observed an excess of G-quadruplex motifs towards the 5'-ends of 5'-UTRs, supportive of a hypothesis linking 5'-UTR RNA G-quadruplexes to translational control. We then analysed the vicinity of 3'-UTRs and observed an over-representation of G-quadruplex motifs immediately after the 3'-end of genes, especially in those cases where another gene is in close proximity, suggesting that G-quadruplexes may be involved in the termination of gene transcription.
authors.affiliation: Cavendish Laboratory, University of Cambridge, JJ Thompson Ave, Cambridge, UK. jlh29@cam.ac.uk
authors.forename: Julian Leon
authors.initials: JL
authors.lastname: Huppert
authors.forename: Anthony
authors.initials: A
authors.lastname: Bugaut
authors.forename: Sunita
authors.initials: S
authors.lastname: Kumari
authors.forename: Shankar
authors.initials: S
authors.lastname: Balasubramanian
mesh_terms: D020413:3' Untranslated Regions / Q000737:chemistry*; D020121:5' Untranslated Regions / Q000737:chemistry*; D019295:Computational Biology; D054856:G-Quadruplexes; D005786:Gene Expression Regulation; D023281:Genomics; D006801:Humans
chemical_list: D020413:3' Untranslated Regions; D020121:5' Untranslated Regions