Characterization of three novel RNAi machinery components in C. elegans
View/ Open
Issue Date
2013-08-31Author
Yang, Huan
Publisher
University of Kansas
Format
98 pages
Type
Dissertation
Degree Level
Ph.D.
Discipline
Molecular & Integrative Physiology
Rights
This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
Metadata
Show full item recordAbstract
RNA interference (RNAi) is a homology-based and antisense small RNA-dependent gene silencing mechanism found in most eukaryotes. This dissertation describes identification and characterization of three novel RNAi pathway components in nematode Caenorhabditis elegans: rde-10, rde-11 and rde-12. We demonstrated that they are required for targeted mRNA degradation and the subsequent secondary siRNA biogenesis. The molecular mechanisms for targeted mRNA degradation in C. elegans undergoing RNA interference (RNAi) are not fully understood. Using a combination of genetic, proteomic and biochemical approaches, we have identified a divergent RDE-10/RDE-11 complex that is required for RNAi in C. elegans. Genetic analysis indicates that the RDE-10/RDE-11 complex acts in parallel to nuclear RNAi. Association of the complex with target mRNA is dependent on RDE-1 but not RRF-1, suggesting that target mRNA recognition depends on primary but not secondary short interfering RNA (siRNA). Furthermore, RDE-11 is required for mRNA degradation subsequent to target engagement. Results of deep sequencing analyses reveal a 5-fold decrease in secondary siRNA abundance in rde-10 and rde-11 mutant animals, despite normal primary siRNA and micro-RNA biogenesis. Therefore, the RDE-10/RDE-11 complex is critical for amplifying the exogenous RNAi response. Our work uncovers an essential output of the RNAi pathway in C. elegans. RDE-12, a putative DEAD-box RNA helicase, was identified from the same genetic screen. A GFP
Collections
Items in KU ScholarWorks are protected by copyright, with all rights reserved, unless otherwise indicated.
We want to hear from you! Please share your stories about how Open Access to this item benefits YOU.