Editors' ChoiceGene Expression

Protecting the Genome?

Science's STKE  31 Aug 2004:
Vol. 2004, Issue 248, pp. tw311
DOI: 10.1126/stke.2482004tw311

In plants, the yeast Schizosaccharomyces pombe, and Drosophila, small interfering RNAs (siRNAs) that are generated as part of the RNA interference process can silence gene expression either posttranscriptionally, by the cleavage of homologous target RNAs, or transcriptionally, by inducing the formation of heterochromatin and/or the methylation of homologous DNA sequences. Morris et al. now show that siRNAs can mediate transcriptional gene silencing in human cells when the siRNAs are delivered to the nucleus. siRNAs directed against gene promoter sequences result in methylation of the DNA. Transcriptional gene silencing probably plays a role in defending the genome from transposons and repeated sequences.

K. V. Morris,S. W.-L. Chan, S. E. Jacobsen, D. J. Looney, Small interfering RNA-induced transcriptional gene silencing in human cells. Science 305, 1289-1292 (2004). [Abstract] [Full Text]