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XB-ART-24072
Nucleic Acids Res 1992 Jan 25;202:203-9.
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Optimal tRNA((Ser)Sec) gene activity requires an upstream SPH motif.

Myslinski E , Krol A , Carbon P .


Abstract
The X. laevis tRNA((Ser)Sec) gene is different from the other tRNA genes in that its promoter contains two external elements, a PSE and a TATA box functionally equivalent to those of the U6 snRNA gene. Of the two internal promoters governing classical tRNA gene transcription, only subsists the internal B box. In this report, we show that the tRNA((Ser)Sec) contains in addition an activator element (AE) which we have mapped by extensive mutagenesis. Activation is only dependent on a 15 bp fragment residing between -209 and -195 and containing an SPH motif. In vitro, this element forms a complex with a nuclear protein which is different from the TEF-1 transcriptional activator that binds the SV40 Sph motifs. This AE is versatile since it shows capacity of activating a variety of genes in vivo, including U1 and U6 snRNAs and HSV thymidine kinase. Unexpectedly for an snRNA-related gene, the tRNA((Ser)Sec) is deprived of octamer or octamer-like motifs. The X.laevis tRNA((Ser)Sec) gene represents the first example of a Pol III snRNA-type gene whose activation of transcription is completely octamer-independent.

PubMed ID: 1311068
PMC ID: PMC310355
Article link: Nucleic Acids Res


Species referenced: Xenopus laevis
Genes referenced: mt-tr tead1 tef trna

References [+] :
Ares, Distinct factors with Sp1 and NF-A specificities bind to adjacent functional elements of the human U2 snRNA gene enhancer. 1987, Pubmed