ミシマ ユウイチロウ   Mishima Yuichiro
  三嶋 雄一郎
   所属   京都産業大学  生命科学部 先端生命科学科
   職種   教授
言語種別 英語
発行・発表の年月 2012/01
形態種別 研究論文
査読 査読あり
標題 Translational inhibition by deadenylation-independent mechanisms is central to microRNA-mediated silencing in zebrafish
執筆形態 その他
掲載誌名 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
出版社・発行元 NATL ACAD SCIENCES
巻・号・頁 109(4),pp.1104-1109
担当区分 筆頭著者,責任著者
著者・共著者 Yuichiro Mishima,Akira Fukao,Tomoyoshi Kishimoto,Hiroshi Sakamoto,Toshinobu Fujiwara,Kunio Inoue
概要 MicroRNA (miRNA) is a class of small noncoding RNA approximately 22 nt in length. Animal miRNA silences complementary mRNAs via translational inhibition, deadenylation, and mRNA degradation. However, the underlying molecular mechanisms remain unclear. A key question is whether these three outputs are independently induced by miRNA through distinct mechanisms or sequentially induced within a single molecular pathway. Here, we successfully dissected these intricate outputs of miRNA-mediated repression using zebrafish embryos as a model system. Our results indicate that translational inhibition and deadenylation are independent outputs mediated by distinct domains of TNRC6A, which is an effector protein in the miRNA pathway. Translational inhibition by TNRC6A is divided into two mechanisms: PAM2 motif-mediated interference of poly(A)-binding protein (PABP), and inhibition of 5' cap- and poly(A) tail-independent step(s) by a previously undescribed P-GL motif. Consistent with these observations, we show that, in zebrafish embryos, miRNA inhibits translation of the target mRNA in a deadenylation- and PABP-independent manner at early time points. These results indicate that miRNA exerts multiple posttranscriptional outputs via physically and functionally independent mechanisms and that direct translational inhibition is central to miRNA-mediated repression.
DOI 10.1073/pnas.1113350109
ISSN 0027-8424
PMID 22232654