title: Influence of assembly of siRNA elements into RNA-induced silencing complex by fork-siRNA duplex carrying nucleotide mismatches at the 3'- or 5'-end of the sense-stranded siRNA element.
abstract: RNA interference (RNAi) is a powerful method for suppressing the expression of a gene of interest, and can be induced by 21-25 nucleotide small interfering RNA (siRNA) duplexes homologous to the silenced gene, which function as sequence-specific RNAi mediators in RNA-induced silencing complexes (RISCs). In the previous study, it was shown that fork-siRNA duplexes, whose sense-stranded siRNA elements carried a few nucleotide mismatches at the 3'-ends against the antisense-stranded siRNA elements, could enhance RNAi activity more than conventional siRNA duplexes in cultured mammalian cells. In this study, we further characterized fork-siRNA duplexes using reporter plasmids carrying target sequences complementary to the sense- or antisense-stranded siRNA elements in the untranslated region of Renilla luciferase. The data presented here suggest that nucleotide mismatches at either the 3'- or 5'-end of the sense-stranded siRNA elements in fork-siRNA duplexes could influence assembly of not only the antisense-stranded siRNA elements but also the sense-stranded elements into RISCs. In addition, we further suggest the possibility that there could be a positional effect of siRNA duplex on RNAi activity.
authors.affiliation: National Institute of Neuroscience, NCNP, 4-1-1 Ogawahigashi, Kodaira, Tokyo 187-8502, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Ohnishi
authors.forename: Katsushi
authors.initials: K
authors.lastname: Tokunaga
authors.forename: Hirohiko
authors.initials: H
authors.lastname: Hohjoh
mesh_terms: D024509:3' Flanking Region / Q000235:genetics; D024506:5' Flanking Region / Q000235:genetics; D020137:Base Pair Mismatch / Q000235:genetics*; D001483:Base Sequence; D005786:Gene Expression Regulation / Q000235:genetics*; D020868:Gene Silencing; D006367:HeLa Cells; D006801:Humans; D008156:Luciferases / Q000235:genetics*; D008969:Molecular Sequence Data; D012313:RNA / Q000235:genetics*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics*; D013329:Structure-Activity Relationship
chemical_list: D034741:RNA, Small Interfering; D012313:RNA; D008156:Luciferases