Northwestern Blot of Protein-RNA Interaction from Young Rice Panicles

Abstract

The northwestern assay is employed to study the interaction between protein and RNA. The RNA binding proteins tend to bind to different kinds of RNA through either known domains or unknown sequences of proteins. Rice LGD1 recombinant protein, a grass-specific novel protein with RNA binding sequences in its C-terminal, was used to probe its function as an RNA binding protein. The LGD1 comprising von Willebrand factor type-A domain (vWA), coiled-coil and nuclear localization signal (NLS) is a class of protein that localizes both in the nucleus and cytoplasm. Although LGD1 does not contain any putative RNA binding domains, we could find high-affinity RNA binding residues at the C-terminus using ‘RNABindR’ prediction software (Terribilini et al., 2007). The LGD1 recombinant protein, purified from bacteria, somehow forms both dimer and monomer even under denaturing conditions. However, only the dimeric form is able to bind to total and mRNAs. Due to its reproducibility and reliability, we believe that this protocol can be used across different organisms.