Abstract
The interaction network of double-stranded RNA (dsRNA) and dsRNA-binding proteins (dsRBPs) is a critical component of various biological processes including gene silencing. We identified seven genes that encode putative dsRBPs, HYL1, ADB2, ADB3, ADB4, CAF, RTL1 and CPL1, in the genome of Arabidopsis thaliana. All seven putative dsRBPs have two conserved dsRNA-binding motifs (dsRBMs) consisting of about 70 amino acid residues, similar to prototypical dsRBMs, such as those of human PKR. Using bacterially produced recombinant proteins, and Northwestern and Far-Westernanalysis, we characterized in vitro dsRNA binding activity and protein-protein interactions for these seven putative dsRBPs. By Northwestern analysis, we demonstrated that HYL1, ADB2, ADB3, ADB4 and CAF bound the 500-bp dsRNA specifically, whereas RTL1 and CPL1 did not. Results of Far-Western analysis indicate that these dsRBPs specifically interact to each other via their dsRBMs.
