Abstract
BackgroundMicro(mi)RNAs regulate gene expression through translational attenuation and messenger (m)RNA degradation, and are associated with differentiation, homeostasis and disease. Natural miRNA target recognition is determined primarily by perfect complementarity in a seed region (nucleotide positions 2 to 7) with additional interactions contributing in a sequence- and target-specific manner. Synthetic miRNA target analogs, which are fully complementary, chemically modified oligonucleotides, have been used successfully to inhibit miRNA function.ResultsIn this paper, we present a first systematic study to evaluate the effect of mismatches in the target site on synthetic inhibitor activity. Panels of miRNA inhibitors containing two-nucleotide mismatches across the target site were tested against three miRNAs (miR-21, miR-22 and miR-122). The results showed that the function of inhibitors vary as mismatch positions in the inhibitors change.ConclusionsThe data indicate that features important for natural miRNA target recognition (such as seed region complementarity) are also important for inhibitor functionality. In addition, base pairing at a second, more 3' region appears to be equally important in determining the efficacy of synthetic inhibitors. Considering the importance of these inhibitor regions and the expression of closely related miRNA sequences will enable researchers to interpret results more accurately in future experiments.
Highlights
Micro(mi)RNAs regulate gene expression through translational attenuation and messenger (m)RNA degradation, and are associated with differentiation, homeostasis and disease
The target sites in these reporters are perfectly complementary to the mature miRNAs, because mismatched/attenuation type target sites were found to be much less sensitive [20]
The data suggest that reporters and inhibitors have different criteria for crossreactivity with endogenous miRNAs
Summary
Micro(mi)RNAs regulate gene expression through translational attenuation and messenger (m)RNA degradation, and are associated with differentiation, homeostasis and disease. Micro (mi)RNAs are small (17 to 27 nucleotides), noncoding RNAs that act in association with Argonaute (Ago) proteins to modulate gene expression via an effector nucleic acid-protein complex (microribonucleoprotein (RNP) or miRNA-induced silencing complex (RISC)). Synthetic miRNA inhibitor designs incorporate the reverse complement of the mature miRNA (the target site) and are chemically modified to prevent RISC-induced cleavage, enhance binding affinity and provide resistance to nucleolytic degradation (for review see [13]). When delivered to a cell, binding of endogenous mature miRNAs to these complementary synthetic target sites is thought to be irreversible, these inhibitors are presumed to sequester the endogenous miRNA, making it unavailable for normal function [14,15,16,17,18,19]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
