title: Recognizing the enemy within: licensing RNA-guided genome defense.
abstract: How do cells distinguish normal genes from transposons? Although much has been learned about RNAi-related RNA silencing pathways responsible for genome defense, this fundamental question remains. The literature points to several classes of mechanisms. In some cases, double-stranded RNA (dsRNA) structures produced by transposon inverted repeats or antisense integration trigger endogenous small interfering RNA (siRNA) biogenesis. In other instances, DNA features associated with transposons--such as their unusual copy number, chromosomal arrangement, and/or chromatin environment--license RNA silencing. Finally, recent studies have identified improper transcript processing events, such as stalled pre-mRNA splicing, as signals for siRNA production. Thus, the suboptimal gene expression properties of selfish elements can enable their identification by RNA silencing pathways.
authors.affiliation: Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94158, USA.
authors.forename: Phillip A
authors.initials: PA
authors.lastname: Dumesic
authors.affiliation: Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94158, USA. Electronic address: hitenmadhani@gmail.com.
authors.forename: Hiten D
authors.initials: HD
authors.lastname: Madhani
mesh_terms: D000818:Animals; D004251:DNA Transposable Elements; D042822:Genomic Instability; D006801:Humans; D016254:Mutagenesis, Insertional; D034622:RNA Interference; D012326:RNA Splicing; D012330:RNA, Double-Stranded / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics*
chemical_list: D004251:DNA Transposable Elements; D012330:RNA, Double-Stranded; D034741:RNA, Small Interfering
keywords: PIWI-interacting RNA; RNAi; genome defense; small RNA; small interfering RNA; transposon