
An Overview of Chemical Modifications to CRISPR RNA
Presenter: Keith Gagnon, Southern Illinois University, USA
Date: March 21, 2019
Description:
CRISPR-based genome editing has emerged as an exciting technology for biomedical and therapeutic applications. Since 2015, a number of studies have explored the effects of chemically modifying the guide RNA components of CRISPR enzymes and the spectrum of modifications that are compatible. While primarily focused on improving editing efficiency or reducing off-target effects, these investigations have led to some important rules regarding the placement and type of modifications that may be used. This webinar will discuss the progress in this area of research and provide practical guidelines for chemically modifying CRISPR RNA.
Recording of the Webinar: Click Play to View
In addition, Dr. Gagnon would like to make the slides available for download: Gagnon OTS webinar
Presenter Biography

Keith Gagnon, Southern Illinois University, USA
Dr. Keith T. Gagnon is an Assistant Professor at Southern Illinois University School of Medicine, USA since 2014 and was elected to the OTS Board of Directors in 2018.
He obtained a BS in Biochemistry (2003) and a PhD in RNA biochemistry (2007) from North Carolina State University. From 2008-2014 he worked as a Post-Doc with Dr. David Corey, where he characterized mechanisms of nuclear RNAi, its necessary cellular machinery and potential for therapeutic application. He also investigated siRNAs and ASOs as therapeutic modalities for repeat expansion disorders, including Huntington’s disease, spinocerebellar ataxia 3, and C9ORF72-associated frontotemporal dementia and amyotrophic lateral sclerosis.
His laboratory focuses on two areas: neurological repeat expansion disorders and RNA-guided enzymes. For the latter, his research focuses on the design, development, and control of CRISPR-based proteins for therapeutic applications, including chemical modification and RNA-protein engineering.
References
- Stepping toward therapeutic CRISPR.
Gagnon KT, Corey DR.
Proc Natl Acad Sci U S A. 2015 Dec 22;112(51):15536-7. - Synthetic CRISPR RNA-Cas9-guided genome editing in human cells.
Rahdar M, McMahon MA, Prakash TP, Swayze EE, Bennett CF, Cleveland DW.
Proc Natl Acad Sci U S A. 2015 Dec 22;112(51):E7110-7. - Chemically modified guide RNAs enhance CRISPR-Cas genome editing in human primary cells.
Hendel A, Bak RO, Clark JT, Kennedy AB, Ryan DE, Roy S, Steinfeld I, Lunstad BD, Kaiser RJ, Wilkens AB, Bacchetta R, Tsalenko A, Dellinger D, Bruhn L, Porteus MH.
Nat Biotechnol. 2015 Sep;33(9):985-989. - Minimal 2′-O-methyl phosphorothioate linkage modification pattern of synthetic guide RNAs for increased stability and efficient CRISPR-Cas9 gene editing avoiding cellular toxicity.
Basila M, Kelley ML, Smith AVB.
PLoS One. 2017 Nov 27;12(11):e0188593. - Engineering CRISPR-Cpf1 crRNAs and mRNAs to maximize genome editing efficiency.
Li B, Zhao W, Luo X, Zhang X, Li C, Zeng C, Dong Y.
Nat Biomed Eng. 2017 May;1(5). pii: 0066. - Extension of the crRNA enhances Cpf1 gene editing in vitro and in vivo.
Park HM, Liu H, Wu J, Chong A, Mackley V, Fellmann C, Rao A, Jiang F, Chu H, Murthy N, Lee K.
Nat Commun. 2018 Aug 17;9(1):3313. - Mapping the sugar dependency for rational generation of a DNA-RNA hybrid-guided Cas9 endonuclease.
Rueda FO, Bista M, Newton MD, Goeppert AU, Cuomo ME, Gordon E, Kröner F, Read JA, Wrigley JD, Rueda D, Taylor BJM.
Nat Commun. 2017 Nov 20;8(1):1610. - Partial DNA-guided Cas9 enables genome editing with reduced off-target activity.
Yin H, Song CQ, Suresh S, Kwan SY, Wu Q, Walsh S, Ding J, Bogorad RL, Zhu LJ, Wolfe SA, Koteliansky V, Xue W, Langer R, Anderson DG.
Nat Chem Biol. 2018 Mar;14(3):311-316. - Chimeric Guides Probe and Enhance Cas9 Biochemical Activity.
Kartje ZJ, Barkau CL, Rohilla KJ, Ageely EA, Gagnon KT.
Biochemistry. 2018 May 29;57(21):3027-3031. - Improving CRISPR-Cas specificity with chemical modifications in single-guide RNAs.
Ryan DE, Taussig D, Steinfeld I, Phadnis SM, Lunstad BD, Singh M, Vuong X, Okochi KD, McCaffrey R, Olesiak M, Roy S, Yung CW, Curry B, Sampson JR, Bruhn L, Dellinger DJ.
Nucleic Acids Res. 2018 Jan 25;46(2):792-803. - Incorporation of bridged nucleic acids into CRISPR RNAs improves Cas9 endonuclease specificity.
Cromwell CR, Sung K, Park J, Krysler AR, Jovel J, Kim SK, Hubbard BP.
Nat Commun. 2018 Apr 13;9(1):1448. - Chemically Modified Cpf1-CRISPR RNAs Mediate Efficient Genome Editing in Mammalian Cells.
McMahon MA, Prakash TP, Cleveland DW, Bennett CF, Rahdar M.
Mol Ther. 2018 May 2;26(5):1228-1240. - Structure-guided chemical modification of guide RNA enables potent non-viral in vivo genome editing.
Yin H, Song CQ, Suresh S, Wu Q, Walsh S, Rhym LH, Mintzer E, Bolukbasi MF, Zhu LJ, Kauffman K, Mou H, Oberholzer A, Ding J, Kwan SY, Bogorad RL, Zatsepin T, Koteliansky V, Wolfe SA, Xue W, Langer R, Anderson DG.
Nat Biotechnol. 2017 Dec;35(12):1179-1187. - Heavily and fully modified RNAs guide efficient SpyCas9-mediated genome editing.
Mir A, Alterman JF, Hassler MR, Debacker AJ, Hudgens E, Echeverria D, Brodsky MH, Khvorova A, Watts JK, Sontheimer EJ.
Nat Commun. 2018 Jul 6;9(1):2641. - Extensive CRISPR RNA modification reveals chemical compatibility and structure-activity relationships for Cas9 biochemical activity.
O’Reilly D, Kartje ZJ, Ageely EA, Malek-Adamian E, Habibian M, Schofield A, Barkau CL, Rohilla KJ, DeRossett LB, Weigle AT, Damha MJ, Gagnon KT.
Nucleic Acids Res. 2019 Jan 25;47(2):546-558.