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Updated: Jun 27, 2026

Electrophoretic Mobility Shift Assay (EMSA) for the Study of RNA-Protein Interactions: The IRE/IRP Example
Published on: December 3, 2014
Human initiation factor eIF3 subunit b interacts with HCV IRES RNA through its N-terminal RNA recognition motif
Julien Pérard1, Rodolfo Rasia, Jan Medenbach
1Unit of Virus Host-Cell Interactions, UJF-EMBL-CNRS (UMR 5233), Grenoble, France.
Abstract:
Many viral mRNAs contain a 5'-UTR RNA element called internal ribosome-entry site (IRES), which bypasses the requirement of some canonical initiation factors allowing cap-independent translation. The IRES of hepatitis-C virus drives translation by directly recruiting 40S ribosomal subunits and binds to eIF3 which plays a critical role in both cap-dependent and cap-independent translation. However, the molecular basis for eIF3 activity in either case remains enigmatic. Here we report that subunit b of the eIF3 complex directly binds to HCV IRES domain III via its N-terminal-RRM. Because eIF3b was previously shown to be involved in eIF3j binding, biological implications are discussed.
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