title: Argonaute2 cleaves the anti-guide strand of siRNA during RISC activation.
abstract: The mRNA-cleavage step of RNA interference is mediated by an endonuclease, Argonaute2 (Ago2), within the RNA-induced silencing complex (RISC). Ago2 uses one strand of the small interfering (si) RNA duplex as a guide to find messenger RNAs containing complementary sequences and cleaves the phosphodiester backbone at a specific site measured from the guide strand's 5' end. Here, we show that both strands of siRNA get loaded onto Ago2 protein in Drosophila S2 cell extracts. The anti-guide strand behaves as a RISC substrate and is cleaved by Ago2. This cleavage event is important for the removal of the anti-guide strand from Ago2 protein and activation of RISC.
authors.affiliation: Department of Biochemistry, Howard Hughes Medical Institute, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390, USA.
authors.forename: Tim A
authors.initials: TA
authors.lastname: Rand
authors.forename: Sean
authors.initials: S
authors.lastname: Petersen
authors.forename: Fenghe
authors.initials: F
authors.lastname: Du
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Wang
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D060565:Argonaute Proteins; D001483:Base Sequence; D002460:Cell Line; D002474:Cell-Free System; D029721:Drosophila Proteins / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D006593:Hexokinase / Q000378:metabolism; D034622:RNA Interference; D012330:RNA, Double-Stranded / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D034743:RNA-Induced Silencing Complex / Q000378:metabolism*; D043244:Ribonuclease III / Q000378:metabolism
chemical_list: C433807:AGO2 protein, Drosophila; D060565:Argonaute Proteins; D029721:Drosophila Proteins; D012330:RNA, Double-Stranded; D034741:RNA, Small Interfering; D034743:RNA-Induced Silencing Complex; D000255:Adenosine Triphosphate; D006593:Hexokinase; D043244:Ribonuclease III; D005947:Glucose