Guide Strand 3'-End Modifications Regulate siRNA Specificity.

Guide Strand 3'-End Modifications Regulate siRNA Specificity.
Chembiochem. 2016 Oct 12;:
Authors: Valenzuela RA, Onizuka K, Ball-Jones A, Hu T, Suter SR, Beal PA
Abstract
Short interfering RNA (siRNA)-triggered gene knockdown via the RNA interference (RNAi) pathway is widely used to study gene function and siRNA-based therapeutics are in development.However, since the guide strand of an siRNA can function like a natural microRNA (miRNA), siRNAs often repress hundreds of off-target transcripts with complementary only to the seed region (nucleotides 2-8) of the guide strand. Here we describe novel guide strand 3' end modifications derived from 1-ethynylribose and copper-catalyzed azide/alkyne cycloaddition reactions and evaluate their impact on target vs miRNA-like off-target knockdown.Surprisingly, when positioned at the guide strand 3' end the parent 1-ethynylribose modification substantially reduced off-target knockdown while having no measurable effect on on-target knockdown potency.In addition, these modifications are shown to modulate siRNA affinity for the hAgo2 PAZ domain.However, the change in PAZ domain binding affinity is not sufficient to predict a modification's effect on miRNA-like off targeting.
PMID: 27731539 [PubMed - as supplied by publisher]

Source: Chembiochem - October 11, 2016 Category: Biochemistry Authors: Valenzuela RA, Onizuka K, Ball-Jones A, Hu T, Suter SR, Beal PA Tags: Chembiochem Source Type: research