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Updated: May 18, 2026
09:40
RNAi Screening to Identify Postembryonic Phenotypes in C. elegans
Published on: February 13, 2012
SID-5 is an endosome-associated protein required for efficient systemic RNAi in C. elegans
Andrea Hinas1, Amanda J Wright, Craig P Hunter
1Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA. andrea.hinas@imbim.uu.se
Current Biology : CB
|September 18, 2012
Summary
Scientists discovered SID-5, an endosome protein crucial for systemic RNA interference (RNAi) in C. elegans. This protein facilitates the transport of silencing signals between cells, expanding our understanding of the RNAi pathway.
Area of Science:
- Molecular Biology
- Genetics
- Cell Biology
Background:
- Systemic RNA interference (RNAi) in C. elegans involves intercellular transport of silencing signals.
- Previous research suggested endosomal proteins play a role in systemic RNAi, but evidence was inconclusive.
Purpose of the Study:
- To identify and characterize novel proteins involved in systemic RNAi.
- To elucidate the role of endosomal proteins in the transport of RNAi silencing signals.
Main Methods:
- Identification and characterization of SID-5 in C. elegans.
- Analysis of SID-5 localization using fluorescence microscopy.
- Assessment of SID-5 function in systemic RNAi via gene knockdown and rescue experiments.
- Investigation of SID-5's role in the transport of RNAi triggers across the intestine.
Main Results:
- SID-5, an endosome-associated protein, is essential for efficient systemic RNAi from both ingested and expressed double-stranded RNA (dsRNA).
- SID-5 localizes to cytoplasmic foci that overlap with late endosomal markers (RAB-7, LMP-1).
- Knockdown of endosomal proteins affects the localization of SID-5 and LMP-1::GFP.
- Intestine-specific SID-5 expression rescues systemic RNAi in distant tissues.
- SID-5 is required for SID-1-independent transport of ingested RNAi triggers across the intestine.
Conclusions:
- SID-5 is a key endosome-associated protein that promotes intercellular transport of RNAi silencing signals.
- SID-5 represents a novel component of the systemic RNAi pathway, distinct from SID-1, SID-2, and SID-3.
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