Systemic RNAi in Caenorhabditis elegans
Abstract
RNA interference (RNAi) in Caenorhabditis elegans induced by ingestion or injection of double-stranded RNA (dsRNA)spreads throughout the organism and is even transmitted to the progeny. We have identified two proteins required for spreadingof RNAi, SID-1 and SID-2, whose structure, subcellular localization, and expression pattern have been informative forhow dsRNA can be transported into and between cells. SID-1 is a transmembrane protein that functions as a pore or channelthat transports dsRNA into and out of cells. Proteins homologous to SID-1 are present in a wide range of invertebrate andvertebrate animals but are absent from plants. SID-2 is a small transmembrane protein that is expressed in the gut and localizesstrongly to the luminal membrane where it appears to act as a receptor for uptake of dsRNA from the environment.Characterization of SID-2 activity in a variety of Caenorhabditis nematodes indicates that C. elegans SID-2 may have a novelactivity.
Footnotes
- Copyright 2006, Cold Spring Harbor Laboratory Press