Molecular mechanisms governing species-specific transcription of ribosomal RNA

• Published in: Cell Vol. 59; no. 3; pp. 489 - 497
• Main Authors: Bell, Stephen P., Pikaard, Craig S., Reeder, Ron H., Tjian, Robert
• Format: Journal Article
• Language: English
• Published: Cambridge, MA Elsevier Inc 03.11.1989; Cell Press
• Subjects: Animals; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Humans; Molecular and cellular biology; Molecular genetics; Promoter Regions, Genetic; RNA Polymerase I - metabolism; RNA, Ribosomal - genetics; Species Specificity; Transcription Factors - genetics; Transcription Factors - isolation & purification; Transcription Factors - metabolism; Transcription, Genetic; Transcription. Transcription factor. Splicing. Rna processing; Xenopus; Xenopus laevis; Human; In vitro transcription; Gel electrophoresis; Xenopus laevis; Footprinting technique; Amphibia; Salientia; Species specificity; Ion exchange chromatography; Vertebrata; Ribosomal RNA; Transcription factor; Mechanism of action; Nucleic acid
• ISSN: 0092-8674; 1097-4172
• DOI: 10.1016/0092-8674(89)90032-9

An unusual property of ribosomal RNA transcription is the species specificity of promoter recognition. Unexpectedly, the sequence-specific RNA poll transcription factors hUBF and xUBF, isolated from human and Xenopus cells, respectively, recognize the same DNA sequence elements. Despite this similarity in DNA binding activity, neither factor will functionally substitute for the other in reconstituted transcription as-says, suggesting that the specificity of protein-DNA interactions cannot account for the species-specific activation of transcription by hUBF and xUBF. Interestingly, we find that hUBF and xUBF from distinctly different complexes with human SL1 at both the human and Xenopus promoters. Together these results strongly implicate specific protein-protein interactions between transcription factors as an important determinant of promoter selectivity and species specificity.