title: Reversible photo-regulation of a hammerhead ribozyme using a diffusible effector.
abstract: The potential utility of catalytic RNAs and DNAs (ribozymes and deoxyribozymes, respectively) as reagents in molecular biology as well as therapeutic agents for a variety of human diseases, has long been recognized. Although naturally occurring RNA-cleaving ribozymes are typically not subject to feedback control, rational methodologies for the creation of allosteric ribozymes, by functional combination of ribozyme and ligand-responsive aptamer RNA elements, have existed for some years. Here, we report the in vitro selection of RNA aptamers specific for binding one but not the other of two light-induced isomers of a dihydropyrene photo-switch compound, and the utilization of such an aptamer for the construction of the UG-dihydropyrene ribozyme, an allosteric hammerhead ribozyme whose catalysis is controllable by irradiation with visible versus ultraviolet light. In the presence of micromolar concentrations of the photo-switch compound, the ribozyme behaves as a two-state switch, exhibiting a >900-fold difference in catalytic rates between the two irradiation regimes. We anticipate that the UG-dihydropyrene, and other ribozymes like it, may find significant application in the developmental biology of model organisms such as Drosophila melanogaster and Caenorhabditis elegans, as well as in the biomedical sciences.
authors.affiliation: Department of Molecular Biology & Biochemistry, Simon Fraser University, Burnaby, B.C., Canada V5A 1S6.
authors.forename: Hyun-Wu
authors.initials: HW
authors.lastname: Lee
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Robinson
authors.forename: Subhajit
authors.initials: S
authors.lastname: Bandyopadhyay
authors.forename: Reginald H
authors.initials: RH
authors.lastname: Mitchell
authors.forename: Dipankar
authors.initials: D
authors.lastname: Sen
mesh_terms: D000495:Allosteric Site; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000737:chemistry*; D005027:Ethylene Oxide / Q000737:chemistry; D007700:Kinetics; D008027:Light; D008274:Magnesium / Q000737:chemistry; D008956:Models, Chemical; D008969:Molecular Sequence Data; D009841:Oligonucleotides / Q000737:chemistry; D016337:RNA, Catalytic / Q000737:chemistry*; D012689:Sequence Homology, Nucleic Acid; D014466:Ultraviolet Rays
chemical_list: D009841:Oligonucleotides; D016337:RNA, Catalytic; C427204:hammerhead ribozyme; D004247:DNA; D008274:Magnesium; D005027:Ethylene Oxide