title: The sequence and secondary structure of the 3'-UTR affect 3'-end maturation, RNA accumulation, and translation in tobacco chloroplasts.
abstract: RNA maturation and modulation of RNA stability play important roles in chloroplast gene expression. In vitro and in vivo studies have shown that both the 5'- and 3'-untranslated regions (UTRs) contain sequence and structural elements that guide these processes, and interact with specific proteins. We have previously characterized the spinach chloroplast petD 3'-UTR in detail by in vitro approaches. This stem-loop forming sequence is a weak terminator but is required for RNA maturation and also exhibits sequence-specific protein binding. To test petD 3'-UTR function in vivo, tobacco chloroplast transformants were generated containing uidA reporter genes flanked by variants of the petD 3'-UTR, including one which does not form an RNA-protein complex in vitro, and one which lacks a stem-loop structure. Analysis of uidA mRNA indicated that a stable secondary structure is required to accumulate a discrete mRNA, and that changes in the 3'-UTR sequence which affect protein binding in vitro can also affect RNA metabolism in vivo. The 3'-UTR also influenced beta-glucuronidase protein accumulation, but not in proportion to RNA levels. These results raise the possibility that in tobacco chloroplasts, the 3'-UTR may influence translational yield.
authors.affiliation: Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA.
authors.forename: R A
authors.initials: RA
authors.lastname: Monde
authors.forename: J C
authors.initials: JC
authors.lastname: Greene
authors.forename: D B
authors.initials: DB
authors.lastname: Stern
mesh_terms: D020413:3' Untranslated Regions / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D002736:Chloroplasts / Q000235:genetics*; D003573:Cytochrome b Group / Q000235:genetics; D045346:Cytochrome b6f Complex; D005966:Glucuronidase / Q000235:genetics / Q000378:metabolism; D009690:Nucleic Acid Conformation; D010947:Plants, Toxic; D011485:Protein Binding; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D014026:Nicotiana / Q000235:genetics*
chemical_list: D020413:3' Untranslated Regions; D003573:Cytochrome b Group; D012333:RNA, Messenger; D018749:RNA, Plant; D011993:Recombinant Fusion Proteins; C084072:petD protein, cytochrome b(6)f complex; D045346:Cytochrome b6f Complex; D005966:Glucuronidase