Skip to main content
Nucleic Acids Research logoLink to Nucleic Acids Research
. 1985 Dec 20;13(24):8999–9009. doi: 10.1093/nar/13.24.8999

Xenopus ribosomal gene enhancers function when inserted inside the gene they enhance.

P Labhart, R H Reeder
PMCID: PMC318967  PMID: 4080555

Abstract

The ribosomal DNA of Xenopus laevis contains repeated sequence elements in the intergenic spacer region that enhance transcription from the adjacent gene promoter (1,2). Previous work has shown that these RNA polymerase I enhancers influence the target promoter when they are in either orientation, at a distance of several kilobases, and only when they are in cis (3-5). In this work, we further show that enhancer activity is unaffected by inserting the enhancers within the transcription unit whose promoter is being enhanced. In addition, enhancer activity does not interfere with transcription through its sequences. The results suggest that the enhancers act at a point prior to the initiation of transcription and that they are likely to be dispensable once transcription has begun.

Full text

PDF
8999

Images in this article

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Bach R., Allet B., Crippa M. Sequence organization of the spacer in the ribosomal genes of Xenopus clivii and Xenopus borealis. Nucleic Acids Res. 1981 Oct 24;9(20):5311–5330. doi: 10.1093/nar/9.20.5311. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Bakken A., Morgan G., Sollner-Webb B., Roan J., Busby S., Reeder R. H. Mapping of transcription initiation and termination signals on Xenopus laevis ribosomal DNA. Proc Natl Acad Sci U S A. 1982 Jan;79(1):56–60. doi: 10.1073/pnas.79.1.56. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Banerji J., Olson L., Schaffner W. A lymphocyte-specific cellular enhancer is located downstream of the joining region in immunoglobulin heavy chain genes. Cell. 1983 Jul;33(3):729–740. doi: 10.1016/0092-8674(83)90015-6. [DOI] [PubMed] [Google Scholar]
  4. Banerji J., Rusconi S., Schaffner W. Expression of a beta-globin gene is enhanced by remote SV40 DNA sequences. Cell. 1981 Dec;27(2 Pt 1):299–308. doi: 10.1016/0092-8674(81)90413-x. [DOI] [PubMed] [Google Scholar]
  5. Boseley P., Moss T., Mächler M., Portmann R., Birnstiel M. Sequence organization of the spacer DNA in a ribosomal gene unit of Xenopus laevis. Cell. 1979 May;17(1):19–31. doi: 10.1016/0092-8674(79)90291-5. [DOI] [PubMed] [Google Scholar]
  6. Brown D. D. The role of stable complexes that repress and activate eucaryotic genes. Cell. 1984 Jun;37(2):359–365. doi: 10.1016/0092-8674(84)90366-0. [DOI] [PubMed] [Google Scholar]
  7. Busby S. J., Reeder R. H. Spacer sequences regulate transcription of ribosomal gene plasmids injected into Xenopus embryos. Cell. 1983 Oct;34(3):989–996. doi: 10.1016/0092-8674(83)90556-1. [DOI] [PubMed] [Google Scholar]
  8. Chandler V. L., Maler B. A., Yamamoto K. R. DNA sequences bound specifically by glucocorticoid receptor in vitro render a heterologous promoter hormone responsive in vivo. Cell. 1983 Jun;33(2):489–499. doi: 10.1016/0092-8674(83)90430-0. [DOI] [PubMed] [Google Scholar]
  9. Ephrussi A., Church G. M., Tonegawa S., Gilbert W. B lineage--specific interactions of an immunoglobulin enhancer with cellular factors in vivo. Science. 1985 Jan 11;227(4683):134–140. doi: 10.1126/science.3917574. [DOI] [PubMed] [Google Scholar]
  10. Gillies S. D., Morrison S. L., Oi V. T., Tonegawa S. A tissue-specific transcription enhancer element is located in the major intron of a rearranged immunoglobulin heavy chain gene. Cell. 1983 Jul;33(3):717–728. doi: 10.1016/0092-8674(83)90014-4. [DOI] [PubMed] [Google Scholar]
  11. Khoury G., Gruss P. Enhancer elements. Cell. 1983 Jun;33(2):313–314. doi: 10.1016/0092-8674(83)90410-5. [DOI] [PubMed] [Google Scholar]
  12. Klein S., Sablitzky F., Radbruch A. Deletion of the IgH enhancer does not reduce immunoglobulin heavy chain production of a hybridoma IgD class switch variant. EMBO J. 1984 Nov;3(11):2473–2476. doi: 10.1002/j.1460-2075.1984.tb02158.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Labhart P., Reeder R. H. Enhancer-like properties of the 60/81 bp elements in the ribosomal gene spacer of Xenopus laevis. Cell. 1984 May;37(1):285–289. doi: 10.1016/0092-8674(84)90324-6. [DOI] [PubMed] [Google Scholar]
  14. Moreau P., Hen R., Wasylyk B., Everett R., Gaub M. P., Chambon P. The SV40 72 base repair repeat has a striking effect on gene expression both in SV40 and other chimeric recombinants. Nucleic Acids Res. 1981 Nov 25;9(22):6047–6068. doi: 10.1093/nar/9.22.6047. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Morgan G. T., Reeder R. H., Bakken A. H. Transcription in cloned spacers of Xenopus laevis ribosomal DNA. Proc Natl Acad Sci U S A. 1983 Nov;80(21):6490–6494. doi: 10.1073/pnas.80.21.6490. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Morgan G. T., Roan J. G., Bakken A. H., Reeder R. H. Variations in transcriptional activity of rDNA spacer promoters. Nucleic Acids Res. 1984 Aug 10;12(15):6043–6052. doi: 10.1093/nar/12.15.6043. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Moss T. A transcriptional function for the repetitive ribosomal spacer in Xenopus laevis. Nature. 1983 Mar 17;302(5905):223–228. doi: 10.1038/302223a0. [DOI] [PubMed] [Google Scholar]
  18. Reeder R. H. Enhancers and ribosomal gene spacers. Cell. 1984 Sep;38(2):349–351. doi: 10.1016/0092-8674(84)90489-6. [DOI] [PubMed] [Google Scholar]
  19. Reeder R. H., Roan J. G., Dunaway M. Spacer regulation of Xenopus ribosomal gene transcription: competition in oocytes. Cell. 1983 Dec;35(2 Pt 1):449–456. doi: 10.1016/0092-8674(83)90178-2. [DOI] [PubMed] [Google Scholar]
  20. Sassone-Corsi P., Wildeman A., Chambon P. A trans-acting factor is responsible for the simian virus 40 enhancer activity in vitro. Nature. 1985 Feb 7;313(6002):458–463. doi: 10.1038/313458a0. [DOI] [PubMed] [Google Scholar]
  21. Sollner-Webb B., Reeder R. H. The nucleotide sequence of the initiation and termination sites for ribosomal RNA transcription in X. laevis. Cell. 1979 Oct;18(2):485–499. doi: 10.1016/0092-8674(79)90066-7. [DOI] [PubMed] [Google Scholar]
  22. Trendelenburg M. F., Gurdon J. B. Transcription of cloned Xenopus ribosomal genes visualised after injection into oocyte nuclei. Nature. 1978 Nov 16;276(5685):292–294. doi: 10.1038/276292a0. [DOI] [PubMed] [Google Scholar]
  23. Wabl M. R., Burrows P. D. Expression of immunoglobulin heavy chain at a high level in the absence of a proposed immunoglobulin enhancer element in cis. Proc Natl Acad Sci U S A. 1984 Apr;81(8):2452–2455. doi: 10.1073/pnas.81.8.2452. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Nucleic Acids Research are provided here courtesy of Oxford University Press

RESOURCES