Inhibition of translation in living eukaryotic cells by an RNA G-quadruplex motif
- Amit Arora1,2,
- Mariola Dutkiewicz1,
- Vinod Scaria3,
- Manoj Hariharan3,
- Souvik Maiti2, and
- Jens Kurreck1,4
- 1Institute for Chemistry and Biochemistry, Free University of Berlin, Berlin, Germany
- 2Proteomics and Structural Biology Unit, Institute of Genomics and Integrative Biology, Delhi, India
- 3GN Ramachandran Knowledge Center for Genome Informatics, Institute of Genomics and Integrative Biology, Delhi, India
- 4Institute of Industrial Genetics, University of Stuttgart, Stuttgart, Germany
Abstract
Guanine-rich sequences can adopt intramolecular four-stranded structures, called G-quadruplexes. These motifs have been intensively investigated on the DNA level, but their overall biological relevance remains elusive. Only recently has research concerning the function of G-quadruplexes in RNAs commenced. Here, we demonstrate for the first time, that an RNA G-quadruplex structure inhibits translation in vivo in eukaryotic cells. We investigated the function of a highly conserved, thermodynamically stable RNA G-quadruplex in the 5′-UTR of the mRNA of the human Zic-1 zinc-finger protein. Using dual luciferase reporter assay, we demonstrate that the Zic-1 RNA G-quadruplex represses protein synthesis inside eukaryotic cells. Quantitative RT-PCR assays confirmed that the reduction of protein synthesis is due to regulation of the translation process and not a consequence of reduced transcription. Western blot analysis revealed that expression of Zic-1 is strongly reduced by a 73 nucleotides-long fragment of the UTR containing the G-quadruplex motif. These structures might add to the more recently discovered elements in untranslated regions of mRNAs that regulate their translation.
Keywords
Footnotes
-
Reprint requests to: Souvik Maiti, Proteomics and Structural Biology Unit, Institute of Genomics and Integrative Biology, CSIR, Mall Road, Delhi 110 007, India; e-mail: souvik{at}igib.res.in; fax: +91 011 27667471; or Jens Kurreck, Institute of Industrial Genetics, University of Stuttgart, Allmandring 31, 70569 Stuttgart, Germany; e-mail: jens.kurreck{at}iig.uni-stuttgart.de; fax: +49 711 685 66 973.
-
Article published online ahead of print. Article and publication date are at http://www.rnajournal.org/cgi/doi/10.1261/rna.1001708.
-
- Received January 11, 2008.
- Accepted April 5, 2008.
- Copyright © 2008 RNA Society