Dumesic PA, Madhani HD. Recognizing the enemy within: licensing RNA-guided genome defense.
Trends Biochem Sci 2013;
39:25-34. [PMID:
24280023 DOI:
10.1016/j.tibs.2013.10.003]
[Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 10/26/2013] [Accepted: 10/28/2013] [Indexed: 02/06/2023]
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.
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