High resolution studies of the Xenopus laevis ribosomal gene promoter in vivo and in vitro.
The first high resolution maps of the Xenopus laevis ribosomal promoter and its flanking regions (-179 to +14) have been created by assaying point mutants both in oocyte and in vitro. Within the promoter boundaries (-141(-145) to +3(+4)), domains analogous to the Core Promoter and "Upstream Control Element" (UCE) were clearly detected. The base pairs at -133, within the UCE, and -20, -10, -7, and +3, within the Core, were all shown to be especially important for promotion. Between the Core and UCE, two central promoter elements (CPEs) were also resolved. Surprisingly, these CPEs did not correspond to the highly conserved enhancer homology (approximately -70 to -110), but to CCCGGCC motifs immediately flanking it. Although xUBF was shown to be a limiting component for in vitro transcription, none of the point mutations was found to affect the interaction of this factor with the promoter.
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Biophysics Laboratories, Portsmouth Polytechnic, United Kingdom.
Larose
A M
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Leblanc
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Bannister
A J
AJ
Firek
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Smith
D R
DR
Moss
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D000818:Animals; D001483:Base Sequence; D016172:DNA Fingerprinting; D004275:DNA, Ribosomal / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation; D010957:Plasmids; D035463:Pol1 Transcription Initiation Complex Proteins; D011401:Promoter Regions, Genetic; D012322:RNA Precursors / Q000235:genetics; D012335:RNA, Ribosomal / Q000235:genetics; D015183:Restriction Mapping; D013698:Templates, Genetic; D014157:Transcription Factors / Q000235:genetics; D014158:Transcription, Genetic; D014982:Xenopus laevis
D004275:DNA, Ribosomal; D004268:DNA-Binding Proteins; D035463:Pol1 Transcription Initiation Complex Proteins; D012322:RNA Precursors; D012335:RNA, Ribosomal; D014157:Transcription Factors; C063844:transcription factor UBF