Rde 4 sandbox: Difference between revisions

In C. elegans, exogenous dsRNA is detected and bound by RDE-4, which stimulates dicer activity. RDE-4 initiates the siRNA pathway by binding to long dsRNA and assisting Dcr-1, a Dicer1 homologue, to facilitate siRNA production. RDE-4 interacts with Dcr-1, RDE-1, DRH-1 (Dicer-related helicase 1) and long dsRNA, which thereby suggests that RDE-4 is required only for the initiation of the RNAi pathway to generate siRNA, although high levels of dsRNA abrogate RDE-4’s role in the RNAi initiation. RDE-4 co- operatively binds to long dsRNA with nanomolar affinity, but exhibits micromolar affinity for short dsRNA, and the enhanced affinity arises from binding of several RDE-4 molecules to a single long dsRNA. <ref name=third>DOI: 10.1016/j.jmb.2008.10.002</ref> The C-terminal region of RDE-4 is necessary and sufficient to induce homodimerization RDE-4 linker– dsRBD2 are absolutely essential in C. elegans gene silencing and RDE-4 dsRBD1 and the C-terminal domain do not have any primary role in vivo. RDE-4 recognizes the A-form of nucleic acid structure adopted by dsRNA and the interaction is sequence-independent.<ref name=second/> RDE-4 dimerization is important for the assembly of active RDE-4/Dicer complexes via one of two proposed scenarios, proper Dicer recruitment to dsRNA, or facilitating Dicer dimerization. <ref name=first/>  

== References ==

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