Dicer is dispensable for asymmetric RISC loading in mammals

• Published in: RNA (Cambridge) Vol. 18; no. 1; pp. 24 - 30
• Main Authors: Betancur, Juan G, Tomari, Yukihide
• Format: Journal Article
• Language: English
• Published: United States Cold Spring Harbor Laboratory Press 01.01.2012
• Subjects: Animals; Base Sequence; Cell Line; DEAD-box RNA Helicases - chemistry; DEAD-box RNA Helicases - genetics; DEAD-box RNA Helicases - metabolism; Mice; Ribonuclease III - chemistry; Ribonuclease III - genetics; Ribonuclease III - metabolism; RNA, Small Interfering - chemistry; RNA, Small Interfering - metabolism; RNA-Induced Silencing Complex - chemistry; RNA-Induced Silencing Complex - genetics; RNA-Induced Silencing Complex - metabolism
• ISSN: 1355-8382; 1469-9001
• DOI: 10.1261/rna.029785.111

In flies, asymmetric loading of small RNA duplexes into Argonaute2-containing RNA-induced silencing complex (Ago2-RISC) requires Dicer-2/R2D2 heterodimer, which acts as a protein sensor for the thermodynamic stabilities of the ends of small RNA duplexes. However, the mechanism of small RNA asymmetry sensing in mammalian RISC assembly remains obscure. Here, we quantitatively examined RISC assembly and target silencing activity in the presence or absence of Dicer in mammals. Our data show that, unlike the well-characterized fly Ago2-RISC assembly pathway, mammalian Dicer is dispensable for asymmetric RISC loading in vivo and in vitro.