| Autor: |
Ruda VM; Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America., Chandwani R; Laboratory of Immune Cell Epigenetics and Signaling, Rockefeller University, New York, New York, United States of America., Sehgal A; Alnylam Pharmaceuticals, Cambridge, Massachusetts, United States of America., Bogorad RL; Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America., Akinc A; Alnylam Pharmaceuticals, Cambridge, Massachusetts, United States of America., Charisse K; Alnylam Pharmaceuticals, Cambridge, Massachusetts, United States of America., Tarakhovsky A; Laboratory of Immune Cell Epigenetics and Signaling, Rockefeller University, New York, New York, United States of America., Novobrantseva TI; Alnylam Pharmaceuticals, Cambridge, Massachusetts, United States of America., Koteliansky V; Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America. |
| Abstrakt: |
Argonaute 2 (Ago2) is the only mammalian Ago protein capable of mRNA cleavage. It has been reported that the activity of the short interfering RNA targeting coding sequence (CDS), but not 3' untranslated region (3'UTR) of an mRNA, is solely dependent on Ago2 in vitro. These studies utilized extremely high doses of siRNAs and overexpressed Ago proteins, as well as were directed at various highly expressed reporter transgenes. Here we report the effect of Ago2 in vivo on targeted knockdown of several endogenous genes by siRNAs, targeting both CDS and 3'UTR. We show that siRNAs targeting CDS lose their activity in the absence of Ago2, whereas both Ago1 and Ago3 proteins contribute to residual 3'UTR-targeted siRNA-mediated knockdown observed in the absence of Ago2 in mouse liver. Our results provide mechanistic insight into two components mediating RNAi under physiological conditions: mRNA cleavage dependent and independent. In addition our results contribute a novel consideration for designing most efficacious siRNA molecules with the preference given to 3'UTR targeting as to harness the activity of several Ago proteins. |
