| First Author | Pikaard CS | Year | 1990 |
| Journal | Mol Cell Biol | Volume | 10 |
| Issue | 9 | Pages | 4816-25 |
| PubMed ID | 2388626 | Mgi Jnum | J:27707 |
| Mgi Id | MGI:75195 | Doi | 10.1128/mcb.10.9.4816 |
| Citation | Pikaard CS, et al. (1990) Enhancers for RNA polymerase I in mouse ribosomal DNA. Mol Cell Biol 10(9):4816-25 |
| abstractText | The intergenic spacer of the mouse ribosomal genes contains repetitive 140-base-pair (bp) elements which we show are enhancers for RNA polymerase I transcription analogous to the 60/81-bp repetitive enhancers (enhancers containing a 60-bp and an 81-bp element) previously characterized from Xenopus laevis. In rodent cell transfection assays, the 140-bp repeats stimulated an adjacent mouse polymerase I promoter when located in cis and competed with it when located in trans. Remarkably, in frog oocyte injection assays, the 140-bp repeats enhanced a frog ribosomal gene promoter as strongly as did the homologous 60/81-bp repeats. Mouse 140-bp repeats also competed against frog promoters in trans. The 140-bp repeats bound UBF, a DNA-binding protein we have purified from mouse extracts that is the mouse homolog of polymerase I transcription factors previously isolated from frogs and humans. The DNA-binding properties of UBF are conserved from the mouse to the frog. The same regulatory elements (terminators, gene and spacer promoters, and enhancers) have now been identified in both a mammalian and an amphibian spacer, and they are found in the same relative order. Therefore, this arrangement of elements probably is widespread in nature and has important functional consequences. |
