RNA-binding protein Dnd1 inhibits microRNA access to target mRNA (Cell, 2007, 131:1273-1286)

報告日期: 2008/06/03
報告時間: 15:10/16:00
報告學生: 楊淨雯
講評老師: 林永明


RNA-Binding Protein Dnd1 Inhibits MicroRNA Access to Target mRNA

Cell, Vol 131, 1273-1286, 28 December 2007


Speaker: Yang Ching-Wen (楊淨雯)

Commentator: Lin Yung Ming (林永明)

Time: 3/6/2008 15:10-16:00

Place: Room 602



MicroRNAs (miRNA) are ~21 nucleotide (nt)-long RNA regulators which control gene expression n in metazoan animals and plants at posttranscriptional level. They utilize a seed sequence at 5’ end to associate with 3’UTR regions of mRNA to suppress gene expression. Here the author used functional genetic-screening approach to identify the miRNA-mRNA interaction between p27 and miR-221 and found that some RNA binding proteins or other factors that may influence the activity of the miRNA pathway. Dnd1 is a RNA-binding protein which has been shown to regulate germ-cell viability and suppress the formation of germ-cell tumors, but the mechanism has remained unresolved. The author find that Dnd1 relieves miRNA repression by binding to U-rich region in mRNA therefore mediates suppression of miRNAs. It indicates that, by binding to target mRNAs, Dnd1 blocks their interaction with miRNAs and thereby protects mRNAs from miRNA-mediated repression. It is predicted that this mechanism can be responsible for defects in germ-cell survival or for tumor formation.



1.     le Sage, C., Maira, G., Mercatelli, N., Ciafre, S.A., et al. (2007). Regulation of the p27 (Kip1) tumor suppressor by miR-221 and miR-222 promotes cancer cell proliferation. EMBO J. 26, 3699-3708