RNAi: RISC gets loaded.
When an siRNA or miRNA proceeds through the RNA-induced silencing complex assembly pathway, only one of the two approximately 21-nucleotide RNA strands survives in the final, active complex. In this issue of Cell, Matranga et al. (2005) and Rand et al. (2005) reveal the fate of the rejected passenger siRNA strand. Additionally, Gregory et al. (2005) define a heterotrimeric complex from humans that appears to execute dsRNA loading, strand selection, and target mRNA cleavage activities.
Preall
Jonathan B
JB
Department of Biochemistry, Molecular Biology & Cell Biology, Northwestern University, Evanston, Illinois 60208, USA.
Sontheimer
Erik J
EJ
D000818:Animals; D060565:Argonaute Proteins; D029721:Drosophila Proteins / Q000378:metabolism; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism; D006801:Humans; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism; D008957:Models, Genetic; D034622:RNA Interference / Q000502:physiology*; D012330:RNA, Double-Stranded / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism*; D034743:RNA-Induced Silencing Complex / Q000378:metabolism*
C433807:AGO2 protein, Drosophila; D060565:Argonaute Proteins; D029721:Drosophila Proteins; D035683:MicroRNAs; D012330:RNA, Double-Stranded; D034741:RNA, Small Interfering; D034743:RNA-Induced Silencing Complex