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- RNAi-Pathway Components and Mechanisms
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39 min
1. Activation of gene expression by double-stranded RNAs- Prof. Long-Cheng Li
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31 min
2. MicroRNA biogenesis- Dr. Narry Kim
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35 min
3. Dicer and R2D2- Dr. Young Sik Lee
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26 min
4. Mammalian microRNA assembly and function- Prof. Zissimos Mourelatos
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33 min
5. Mechanisms of RNAi: a molecular view or Argonaute: the secret life of Slicer- Prof. Leemor Joshua-Tor
- Roles for RNAi in Development and Anti-Viral Defense
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38 min
6. Functional roles of RNAi in C. elegans- Dr. Eric Miska
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41 min
7. RNAi and heterochromatin in plants and fission yeast- Prof. Robert Martienssen
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29 min
8. RNA interference functions and mechanisms in animals- Prof. Richard Carthew
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40 min
9. Specific functional roles in mammals- Dr. Michael McManus
- RNAi Design Rules for Applications in Humans
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38 min
10. siRNA on and off-target- Prof. Anastasia Khvorova
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43 min
11. Cell signalling pathways and RNAi- Mr. Michael O'Grady
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33 min
12. RNAi: key technological aspects- Dr. Dmitry Samarsky
- Dr. Ciaran Faherty
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28 min
13. RNAi specificity: how big of an issue is it?- Dr. Peter Welch
- Applications of RNAi in the Treatment of Human Diseases
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18 min
14. siRNA therapeutics- Prof. John Rossi
- Mr. Daniel J. Rossi
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48 min
15. RNAi for neurological diseases- Prof. Beverly L. Davidson
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31 min
16. RNA interference and cancer: a revolution?- Dr. Annick Harel-Bellan
- Archived Lectures *These may not cover the latest advances in the field
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51 min
17. RNAi and viral heart infections- Dr. Jens Kurreck
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26 min
18. RNA interference for neurodegenerative diseases- Prof. Beverly L. Davidson
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42 min
19. Activation of gene expression by double-stranded RNA- Prof. David Corey
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43 min
20. New designs for siRNAs as Dicer substrate- Dr. Mark Behlke
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27 min
21. RNAi in the model system Drosophila- Prof. Richard Carthew
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29 min
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37 min
23. Therapeutic delivery of RNAi- Dr. Patrick Lu
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44 min
24. Mechanistic aspects and therapeutic applications of RNAi- Prof. John Rossi
Printable Handouts
Navigable Slide Index
- Introduction
- A brief history of RNA interference (RNAi)
- Increased activity of the CS enzyme
- Landmark paper
- Timeline of important RNAi discoveries
- Biochemical pathways of Dicer and RISC
- Dicer substrate hypothesis
- Design of dsRNA and nomenclature used in study
- Longer duplexes can be more potent
- Map of EGFP target sites
- Improved potency at EGFP site-2 and site-3
- Targeting endogenous genes hnRNPH and La
- Dose response curves for EGFP-S1
- Experiments "in vitro" with various dsRNAs
- 27mer is cleaved "in vivo" to 21 mer size
- Results of dicing EGFP-S1 27+0 "in vitro"
- Tiling experiment
- 27mers can have longer duration of silencing (1)
- 27mers can have longer duration of silencing (2)
- 27mers do not trigger IFN or PKR responses
- 27mer Dicer-substrate dsRNAs as triggers of RNAi
- Example: suppression of STAT1 gene
- Not all 27mers work well - STAT-1 data
- 27mers work better at a TNF-alfa target site
- 27mers work better at a Stratifin target site
- Why do some 27mers work better than others?
- Effect of end modification on dicing
- Understanding dicing patterns
- EGFP-S3 blunt 27mer dicing pattern
- The variety of blunt 27mers dicing patterns
- SAR - structure activity relationship study (1)
- Summary of SAR ESI - dicing studies
- Mass Spec dicing results for EGFP-S1 L-form
- Mass Spec dicing results for EGFP-S1 R-form
- Two different 27mers can produce the same 21mer
- R 27mer is more potent than L 27mer at EGFP-S1
- R 27mer is more potent than L 27mer at EGFP-S2
- R-form more potent for two sites of hnRNPH
- R-form more potent for TNF
- Effect of dicing on 27mer functional asymmetry
- Prior work that may explain R vs. L potency
- Influence of 27mer asymmetry on RISC loading
- R-form favors "AS" strand loading into RISC
- SAR - structure activity relationship study (2)
- The potency of duplexes >30 bp
- RNA is better than DNA in 3'-overhang
- 3'-overhang length does not matter
- Analysis of all possible 3'-overhang sequences
- Central mutations disrupt function
- Test of the potency of the new 27 mer duplexes
- Results of testing the new 27 mer duplexes
- Can new 27 mer designs be used "in vivo"?
- Suppression of galectin-1 by 27mer dsRNA
- Summary
- Credits
- Other collaborating scientists in the project
- Dicer substrate RNAi publications
- References (1)
- References (2)
- References ( 3)
Topics Covered
- Potency of RNA duplexes of ~27 nucleotides in length
- Dicer substrates
- Variation in dicing patterns
- Defined substrate preferences for Dicer
- Design of RNA duplexes that are processed to specific, desired products
- Dicer processing introduces functional asymmetry into the potency of a RNA duplex
- Preferential binding of Dicer to 3'-overhand
- The exploitation of Dicer properties to improve design of RNAi reagents
Talk Citation
Behlke, M. (2007, October 1). New designs for siRNAs as Dicer substrate [Video file]. In The Biomedical & Life Sciences Collection, Henry Stewart Talks. Retrieved April 19, 2025, from https://doi.org/10.69645/HZNH6539.Export Citation (RIS)
Publication History
Financial Disclosures
- Dr. Mark Behlke has not informed HSTalks of any commercial/financial relationship that it is appropriate to disclose.
