@article{60dc7c97760b4f249e73be5014230a53,
title = "Hsc70/Hsp90 chaperone machinery mediates ATP-dependent RISC loading of small RNA duplexes",
abstract = "Small silencing RNAs-small interfering RNAs (siRNAs) or microRNAs (miRNAs)-direct posttranscriptional gene silencing of their mRNA targets as guides for the RNA-induced silencing complex (RISC). Both siRNAs and miRNAs are born double stranded. Surprisingly, loading these small RNA duplexes into Argonaute proteins, the core components of RISC, requires ATP, whereas separating the two small RNA strands within Argonaute does not. Here we show that the Hsc70/Hsp90 chaperone machinery is required to load small RNA duplexes into Argonaute proteins, but not for subsequent strand separation or target cleavage. We envision that the chaperone machinery uses ATP and mediates a conformational opening of Ago proteins so that they can receive bulky small RNA duplexes. Our data suggest that the chaperone machinery may serve as the driving force for the RISC assembly pathway.",
keywords = "Proteins, RNA",
author = "Shintaro Iwasaki and Maki Kobayashi and Mayuko Yoda and Yuriko Sakaguchi and Susumu Katsuma and Tsutomu Suzuki and Yukihide Tomari",
note = "Funding Information: We thank Mikiko and Haruhiko Siomi for anti-dAgo1 and anti-dAgo2 antibodies, Qinghua Liu for anti-R2D2 antibody and baculovirus stocks for expressing Dcr-2 and R2D2, Richard Carthew for dcr-2 R416X flies, and Fen-Biao Gao for ago2 51B flies. We are also grateful to Taichiro Iki, Manabu Yoshikawa, and Masayuki Ishikawa for sharing unpublished results; and Akio Yamashita and Kenji Ohgane for fruitful discussion. We thank Klaus F{\"o}rstemann, Herv{\'e} Seitz, Qinghua Liu, Phillip Zamore, and the members of the Tomari laboratory for suggestions and critical comments on the manuscript. This work was supported in part by a PRESTO program from Japan Science and Technology Agency (JST), a Grant-in-Aid for Young Scientists (A), and a Grant-in-Aid for Scientific Research on Innovative Areas (“Functional machinery for non-coding RNAs”) from the Japan Ministry of Education, Culture, Sports, Science and Technology (MEXT), and a Carrier Development Award from The International Human Frontier Science Program Organization (HFSP) (to Y.T.), and by a grant from the New Energy and Industrial Technology Development Organization (NEDO) (to T.S.). S.I. is a recipient of a JSPS Research Fellowship. ",
year = "2010",
month = jul,
doi = "10.1016/j.molcel.2010.05.015",
language = "English",
volume = "39",
pages = "292--299",
journal = "Molecular Cell",
issn = "1097-2765",
publisher = "Cell Press",
number = "2",
}