A tRNA(Leu)-like sequence located immediately upstream of an Arabidopsis clock-regulated gene is transcriptionally active: efficient transcription by an RNA polymerase III-dependent in vitro transcription system.
A tRNA(Leu)-like sequence is located within a probable enhancer region of the RNA polymerase II-dependent gene encoding an RNA-binding protein, Atgrp7, in Arabidopsis (Mol. Gen. Genet. 261 (1999) 811). To examine whether this sequence is transcribed, we used our in vitro transcription system from tobacco cell nuclei. In vitro assays demonstrated that this tRNA-like sequence is transcribed by RNA polymerase III and its transcript is processed into tRNA-size molecules. Transcription starts at the CAA motif, a transcription initiation site for many plant tRNA genes. Mutation analyses indicated that transcription of this sequence depends on promoter elements typical for plant tRNA genes. We therefore concluded that this is a transcriptionally active tRNA(Leu)(AAG) gene. Mutation of a basic promoter element of the tRNA gene exerted no influence on the transcription of the downstream protein-coding gene, suggesting that no apparent interference occurs between the two adjacent genes.
Hasegawa
Keiko
K
Center for Gene Research, Nagoya University, Nagoya 464-8602, Japan.
Yukawa
Yasushi
Y
Obokata
Junichi
J
Sugiura
Masahiro
M
D024506:5' Flanking Region / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics*; D001483:Base Sequence; D001683:Biological Clocks / Q000502:physiology; D002474:Cell-Free System; D002940:Circadian Rhythm / Q000502:physiology; D018506:Gene Expression Regulation, Plant; D023061:Gene Order; D008969:Molecular Sequence Data; D009154:Mutation; D011401:Promoter Regions, Genetic / Q000235:genetics; D012320:RNA Polymerase III / Q000378:metabolism; D012356:RNA, Transfer, Leu / Q000235:genetics*; D016601:RNA-Binding Proteins / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid; D014026:Nicotiana / Q000166:cytology / Q000235:genetics; D024363:Transcription Initiation Site; D014158:Transcription, Genetic
D029681:Arabidopsis Proteins; D012320:RNA Polymerase III; D012356:RNA, Transfer, Leu; D016601:RNA-Binding Proteins; C118496:GRP7 protein, Arabidopsis