RRC ID 22780
Author Zhu L, Masaki Y, Tatsuke T, Li Z, Mon H, Xu J, Lee JM, Kusakabe T.
Title A MC motif in silkworm Argonaute 1 is indispensible for translation repression.
Journal Insect Mol. Biol.
Abstract Small RNA-mediated gene silencing is a fundamental gene regulatory mechanism, which is conserved in many organisms. Argonaute (Ago) family proteins in the RNA-induced silencing complex (RISC) play crucial roles in RNA interference (RNAi) pathways. In the silkworm Bombyx mori, four Ago proteins have been identified, named as Ago1, Ago2, Ago3 and Siwi. Ago2 participates in double-stranded RNA (dsRNA)-induced RNAi, whereas Ago3 and Siwi are involved in the Piwi-interacting RNA (piRNA) pathway. However, there is no experimental evidence concerning silkworm Ago1 (BmAgo1) in the RNAi mechanism. In the present study, we analysed the function of BmAgo1 in the microRNA (miRNA)-mediated RNAi pathway using tethering and miRNA sensor reporter assays. These results clearly demonstrate that BmAgo1 plays an indispensable role in translation repression in silkworm. Moreover, coimmunoprecipitation data indicated that BmAgo1 interacts with BmDcp2, an orthologue of mRNA-decapping enzyme 2 (Dcp2) protein in the Drosophila processing-bodies (P-bodies). Substitutions of two conserved phenylalanines (F522 and F557) by valines in the MC motif strongly impaired the function of BmAgo1 in translation repression and its localization in P-bodies, suggesting that these two amino acid residues in the MC motif of BmAgo1 are prerequisites for mRNA translation repression in B. mori.
Volume 22(3)
Pages 320-30
Published 2013-6
DOI 10.1111/imb.12023
PMID 23521747
MeSH Amino Acid Motifs Amino Acid Sequence Animals Argonaute Proteins / genetics* Argonaute Proteins / metabolism Bombyx / genetics* Bombyx / metabolism DNA, Complementary / genetics DNA, Complementary / metabolism Immunoprecipitation Insect Proteins / genetics* Insect Proteins / metabolism MicroRNAs / genetics MicroRNAs / metabolism Protein Biosynthesis RNA Interference Sequence Alignment Sequence Analysis, DNA Transcription Factors / genetics* Transcription Factors / metabolism
IF 2.492
Times Cited 5