λN-GFP: an RNA reporter system for live-cell imaging

We describe a GFP-based RNA reporter system (lambdaN-GFP) to visualize RNA molecules in live mammalian cells. It consists of GFP fused to an arginine-rich peptide derived from the phage lambda N protein, lambdaN22, which binds a unique minimal RNA motif and can be used to tag any RNA molecule. LambdaN-GFP uses a small and easy to engineer RNA tag, reducing the likelihood of perturbing the function of the tagged RNA molecule.