Principles of circular RNA translation and immunity
Abstract/Contents
- Abstract
- The rapid development of Covid-19 mRNA therapeutics was enabled by an upfront investment in mRNA platform technology, built on a fundamental understanding of mRNA biology. Decades of mechanistic work have uncovered key drivers of mRNA translation such as the cap, untranslated regions, and poly(A) tail. Additionally, the use of nucleoside modifications such as N1-methylpseudouridine enabled in vivo translation by suppressing innate immune responses to mRNA. Circular RNAs (circRNAs) are single-stranded covalently-closed RNAs whose translation is driven by internal ribosome entry sites (IRESs) and whose structure confers stability advantages over mRNAs. My dissertation defense will describe the circRNA assembly platform I built, its use in uncovering principals behind circRNA translation, and the study of the mechanism of immune sensing of nucleoside modification N6-methyladenosine (m6A) on circRNAs. In order to elucidate principles for driving strong circRNA translation, I built a platform for rapid and robust assembly of vectors and subsequent synthesis of circRNAs. Using this modular system, I identified an optimum format for circRNAs and systematically tested sequence elements that enhanced circRNA translation. I screened 100 viral IRESs, discovered a set with greatly improved translation across cell types, then created novel synthetic IRESs through both rational engineering and random mutagenesis. Further, I characterized a set of nucleoside modifications that improve circRNA translation. We decided to focus on one such modification, m6A, the most abundant post-transcriptional RNA modification on endogenous RNAs. Investigating the interaction behind m6A and anti-circRNA innate immunity, I found that circRNAs without nucleoside modifications activate the antiviral RNA sensor RIG-I in the presence of lysine-63-linked polyubiquitin chains to trigger a downstream interferon response. m6A blunts this response in an m6A reader YTHDF2-dependent manner. Viewed broadly, my findings characterize a mechanism behind self versus non-self recognition of circRNAs. Taken together, my circRNA development platform and the numerous discoveries made with it have pushed circRNAs forward as a promising class of RNA therapeutics.
Description
| Type of resource | text |
|---|---|
| Form | electronic resource; remote; computer; online resource |
| Extent | 1 online resource. |
| Place | California |
| Place | [Stanford, California] |
| Publisher | [Stanford University] |
| Copyright date | 2021; ©2021 |
| Publication date | 2021; 2021 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Chen, Robert, (Researcher of circular RNA translation) |
|---|---|
| Degree supervisor | Chang, Howard Y. (Howard Yuan-Hao), 1972- |
| Thesis advisor | Chang, Howard Y. (Howard Yuan-Hao), 1972- |
| Thesis advisor | Qi, Lei, (Professor of Bioengineering) |
| Thesis advisor | Smolke, Christina D |
| Degree committee member | Qi, Lei, (Professor of Bioengineering) |
| Degree committee member | Smolke, Christina D |
| Associated with | Stanford University, Department of Bioengineering |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | Robert Chen. |
|---|---|
| Note | Submitted to the Department of Bioengineering. |
| Thesis | Thesis Ph.D. Stanford University 2021. |
| Location | https://purl.stanford.edu/fp293mm3387 |
Access conditions
- Copyright
- © 2021 by Robert Chen
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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