Characterization and transcriptional regulation of rat glutamine tRNA-encoding genes: repression of tRNA(UUGGln) synthesis.
In rat liver, the amount of tRNA(UUGGln) (RG-2) was found to be approx. 20% of that of tRNA(CUGGln) (RG-1). The independent RG-1 and RG-2 genes were isolated from a rat genomic library together with four RG-related genes containing two to five alterations in their coding regions. Sequence analysis demonstrated that there was no difference between the internal promoter sequences of RG-1 and RG-2. However, interestingly, the transcriptional activity of RG-1 was approximately four-times higher than that of RG-2 in an in vitro transcription reaction. Replacement of the 5'-flanking sequence of RG-2 by the corresponding sequence of RG-1 or by a plasmid DNA sequence caused activation of RG-2 transcription. Gel retardation assay demonstrated that the 5'-flanking region of RG-2 contained a unique sequence specifically recognized by a nuclear protein. Taken together, these results strongly suggest that the transcriptional activity of RG-2 might be negatively regulated by the binding of a nuclear protein at a specific site in the 5'-flanking region of the gene.
Nemoto
F
F
Biophysics Division, National Cancer Center Research Institute, Tokyo, Japan.
Kohda
T
T
Mizushima
H
H
Yoshikura
H
H
Schröder
H C
HC
Müller
W E
WE
Kuchino
Y
Y
D000818:Animals; D001483:Base Sequence; D004252:DNA Mutational Analysis; D004268:DNA-Binding Proteins / Q000378:metabolism; D005786:Gene Expression Regulation; D005796:Genes / Q000235:genetics*; D008099:Liver / Q000378:metabolism*; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000378:metabolism; D009690:Nucleic Acid Conformation; D011401:Promoter Regions, Genetic / Q000235:genetics; D012351:RNA, Transfer, Gln / Q000235:genetics*; D051381:Rats; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic
D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D012351:RNA, Transfer, Gln