title: TAF11 Assembles the RISC Loading Complex to Enhance RNAi Efficiency.
abstract: Assembly of the RNA-induced silencing complex (RISC) requires formation of the RISC loading complex (RLC), which contains the Dicer-2 (Dcr-2)-R2D2 complex and recruits duplex siRNA to Ago2 in Drosophila melanogaster. However, the precise composition and action mechanism of Drosophila RLC remain unclear. Here we identified the missing factor of RLC as TATA-binding protein-associated factor 11 (TAF11) by genetic screen. Although it is an annotated nuclear transcription factor, we found that TAF11 also associated with Dcr-2/R2D2 and localized to cytoplasmic D2 bodies. Consistent with defective RLC assembly in taf11(-/-) ovary extract, we reconstituted the RLC in vitro using the recombinant Dcr-2-R2D2 complex, TAF11, and duplex siRNA. Furthermore, we showed that TAF11 tetramer facilitates Dcr-2-R2D2 tetramerization to enhance siRNA binding and RISC loading activities. Together, our genetic and biochemical studies define the molecular nature of the Drosophila RLC and elucidate a cytoplasmic function of TAF11 in organizing RLC assembly to enhance RNAi efficiency.
authors.affiliation: Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
authors.forename: Chunyang
authors.initials: C
authors.lastname: Liang
authors.affiliation: Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
authors.forename: Yibing
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Biological Sciences, University of Tokyo, Tokyo 113-0032, Japan.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Murota
authors.affiliation: Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
authors.forename: Xiang
authors.initials: X
authors.lastname: Liu
authors.affiliation: Departments of Pharmacology and Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
authors.forename: Dean
authors.initials: D
authors.lastname: Smith
authors.affiliation: Department of Biological Sciences, University of Tokyo, Tokyo 113-0032, Japan.
authors.forename: Mikiko C
authors.initials: MC
authors.lastname: Siomi
authors.affiliation: Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; International Institute of Integrated Sleep Medicine, University of Tsukuba, Tsukuba 305-8575, Japan. Electronic address: qinghua.liu@utsouthwestern.edu.
authors.forename: Qinghua
authors.initials: Q
authors.lastname: Liu
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D060565:Argonaute Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D064113:CRISPR-Cas Systems; D002460:Cell Line; D029721:Drosophila Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism / Q000821:virology; D005260:Female; D055786:Gene Knockout Techniques; D017344:Genes, Insect; D008297:Male; D008954:Models, Biological; D016296:Mutagenesis; D020836:Protein Structure, Quaternary; D020365:RNA Helicases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D034743:RNA-Induced Silencing Complex / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D043244:Ribonuclease III / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D035381:TATA-Binding Protein Associated Factors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: C433807:AGO2 protein, Drosophila; D060565:Argonaute Proteins; D029721:Drosophila Proteins; C478068:R2D2 protein, Drosophila; D034741:RNA, Small Interfering; D016601:RNA-Binding Proteins; D034743:RNA-Induced Silencing Complex; D035381:TATA-Binding Protein Associated Factors; C478069:DCR-2 protein, Drosophila; D043244:Ribonuclease III; D020365:RNA Helicases