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----- Reading ------------- Writing --------- ArithmELSI ----------- | .gov | .edu | .org | | | .com | | | | | ------ Reading ------------- Writing --------- ArithmELSI ----------
Genome Editing, Codon Recoding. �6-Feb-2018 Biophysics 242 George Church
LSRF
NHGRINIGMS
Azco
OppenheimerFoundation
PersonalGenomes.org
Lipper Foundation
v.ht/PHNc
Biophysics 242: Transformative Biotechnologies (R-W-A) Refactored
Jan 23 (1) Exponential, Logistic, Prioritizing global challenges Jan 30 (2) Sequencing & understanding biosphere omes, 3D molecular design Feb 6 (3) Genome Edit/Write (beyond CRISPR), Codon Recoding Feb 13 (4) In situ Sequencing : Mammalian Cell Atlas & BRAIN Initiative Feb 20 (5) Epigenetic programming, signaling pathways, SynEvoDevo Feb 27 (6) Microbiomes: therapeutics, diagnostics, nanopores Mar 6 (7) Synthetic Organs for VUS & Transplantation Mar 20 (8) Aging Reversal Mar 27 (9) Global Warming Apr 3 (10) Germline editing & H. sapiens 2.0
3
Reading & Writing Genomes: First semi-synthetic plasmid 1978: $10/b
pBR322 5 genes
NAR 1978Sutcliffe & Church(BR:Bolivar & Rodriguez)
Recombinant DNA vector uses • Human insulin • Human growth hormone • Alpha-interferon • G-CSF • TPA • GM-CSF • Gamma-interferon • IL-2 • Erythropoietin • Hepatitis B vaccine (Amgen, Biogen, Genentech, etc)
Gen 1 &2 Oligo Synthesis on chips
5
Phosphoramidite chemistry ~200 sec per base addition300 b max length
Polymerase 10 msec per base>1 Mbase length
Gen 1: $3M per 3 Gb Gen 2: $3K per 3 Gb
Whatcandrivethis?ArchivalInformationstorage
Add v. Subtract v. Precise edit v. Epigenetic
Genomic locusNuclease
DNA donor (homologous flanks)
Homology Directed Repair
(HDR)
Non-Homologous End Joining (NHEJ)
Random Insertion / Deletion
Ser/TyrIntegrase
Group II intron
Cas9
RecACAGE
Mega-nuclease
λ-RedMAGE
8 Editors: 3 DNA, 2 RNA, 4 protein
ZFN
TALEN
30-90% NHEJ 0% Rough Precise
|--| 1 nm
CRISPR as a technology in eukaryotes
1. Precise editing (HR), not merely cutting / NHEJ.2. Editing normal cells, not just cancer cells (abnormally resistant to DNA cuts).3. Avoiding off-target using computer search of the whole genome.4. Using an 3’ extended sgRNA that works reproducibly in eukaryotic cells.5. Using a RNApol III (e.g. U6) promoter to express the guide RNA.6. Codon-optimized Cas9. A - - - - - - 8-Jun-2012 Jinek … DoudnaB 1 - - - 5 6 3-Jan-2013 Cong … ZhangC 1 2 3 4 5 6 3-Jan-2013 Mali … ChurchD - - - - - - 29-Jan-2013 Cho … KimE - - - 4 5 6 29-Jan-2013 Jinek … Doudna�F - 2 - 4 - - 29-Jan-2013 Hwang … JoungG 1 2 3 4 - 6 2-May-2013 Wang … Jaenisch H - 2 - 4 5 6 4-Apr-2013 Ding … MusunuruI 1 2 3 4 5 6 29-Aug-2013 Ran … Zhang
What’s wrong with CRISPR?
1. Need custom RNA, DNA & protein2. Hard to deliver3. Inefficient once delivered4. Off-target errors5. On target errors 6. Expensive (vs genetic counseling)7. Toxic 8. Large DNA & multiplexing is hard9. Immunity
How was Cas9 an improvement over prior art? ��
Ease of use? Cost? ��
Probably not.�
.
Nat Biotechnol. Mar-2013. A library of TAL effector nucleases spanning the human genome. Kim Y … Kim JS “assembled TALEN plasmids for 18,740 protein-coding genes”
HR TALEN vs Cas9
Mali, Yang … Church, Fig 1C Science 3-Jan-2013 Cong … Zhang, Fig 4D
Science 3-Jan-2013
0.37
3.26
8.07HR %
gRNAs
5’ NNNNNNNNNNNNNNNNNNNNGUUUUAGAGCUAUgcu 3’ :|||||: |||||||| AGUUCAACUAUUGCCUGAUCGGAAUAAAAUU CGAUACGACAAAACUUACCAAGG 5’ A |||| GAA AAAGUGGCACCGA :|||||| G 3’ UUUCGUGGCU
5’ NNNNNNNNNNNNNNNNNNNNGUUUUAGAGCUAGA :|||||: |||| A 3’ GCCUGAUCGGAAUAAAAUU CGAU A GAA
5’ NNNNNNNNNNNNNNNNNNNNGUUUUAGAGCUAGA :|||||: |||| A AGUUCAACUAUUGCCUGAUCGGAAUAAAAUU CGAU A A |||| GAA AAAGUGGCACCGA :|||||| G 3’ UUUCGUGGCU
Cong…Zhang 3-Jan-2013 Fig 2B & S2
Jinek…Doudna 28-Jun-2012 Fig 5B
Mali ... Church 3-Jan-2013 Fig 1A
Computational Jan-2013 Mali …Church, Cong…Zhang SciencePaired nickases Aug-2013 Mali…Church Nat Biotech. Truncated guide RNAs Jan-2014 Fu…Joung Nat Biotech. FokI fusion Apr-2014. Tsai...Joung; Guilinger…Liu Nat Biotech. Brief binding Apr-2015 Davis…Liu. Nat Chem Biol. Weak Cas9-dsDNA Jan-2016 Slaymaker ... Zhang ScienceWeak Cas9-ssDNA Jan-2016 Kleinstiver…Joung Nature.
Still none are reliably SNP specific !!
Genome editing Specificity OFF-target issues
hIPSC HR Jan-2013 Mali …Church. ScienceAsym donor DNA Mar 2016 Richardson … Corn. Nat Biotech BE: C-Deaminase 2009 Yang…Church, 2016 Komor…Liu NaturePost-HDR NHEJ May-2016 Pacquet ... Tessier-Lavigne. Nature Apoptosis toxicity 2016 submitted Byrne … Church
3 Alternatives to ds-breaks: Ser/Tyr Integrase/recombinase AAV editing λ-Red recombinase
Beyond CRISPR: ON-target issues (& large chunks)
17 Harris Wang et al Nature 2009
5-fold improvement in 3 days
AND improve growth rates
Accelerated Evolution 23K RBS combinations per gene Lycopene (hydrocarbon): 20 genes up, 4 down, 2 new
8 Optimizations for ss allele replacement
Oligo length 10x
Phosphorothioate 3x
ΔG > –13 kcal/mol 30x
[oligo] = 0.05-50uM
Wang, et al. Nature 2009 Isaacs et al Science 2011 Ellis et al PNAS 2001
Red-β >10,000x MutS 100x
Lagging strand: 30x Co-selection 4x
Genome-scale precise editing�4 Million bp Genome Recoding: 63 & 57 codon types
Science 2016 Ostrov, et al Nature 2015 Mandell et al Science 2013 Lajoie et al2. Genetic &
Metabolic Isolation
3. Multi-Virus resistance
1. Non-standard amino acids (NSAA)321 & 62,214 codons
Codon types impacting all viruses
Ostrov et al Science 2016
UAGStop
+ rare ArgAGAAGG
UUA LeuUUG orAGC SerAGU
ß 4/6 viruses zero yield from 1012 titer
Non-standard Amino Acids
Ketone 9 Orthogonal chem
Azobenzyl 14 Photoisomers
Coumarinyl 13 Redox
Cytosinyl 8 Peptide-NA
Dansyl 17 Fluorescent
Biotinyl-Lys 19 Binds Avidin
Side Chain Key AAAA #atoms(non-H) Features
Clinical tests of non-standard AA “orthogonal” chemistry
PEG-pAcPhe-hGHAmbrx,Cho,Schultzetal.higherserumstability
+hydrazideKetone hydrazone
24 24
Improving a Natural Enzyme Activity through Incorporation of Unnatural Amino Acids -- Ugwumba et al 2010 JACS
8-11-fold improvement … in contrast to … screening hundreds of thousands of mutants with natural amino acids.
Ecologicallyisolatedcells.(metabolically&genetically)
Failure modes: • Near-cognate suppression • tRNA anticodon mutations • UAG reversion
Solutions: • Exclude canonical amino acids • Require compensatory mutations • Reduce spontaneous mutation freq.
• mutS-- 2x10-8 • mutS+ 10-10
Starting with 120 known crystal structures
Mandell et al Nature 2015
33
J. Responsible Innovation. 2017 Harnessing gene drive. Min, Smidler, Najjar, Esvelt
Nature. 2016 Turning point Nature. 2016 Gene editing can drive science to openness. Sci Am. 2017 Unnatural Responsibilities. Science. 2017 Precaution: Open gene drive research. PLoS Biol. 2017 Conservation demands safe gene drive.
Problems. 1A: Please list your help sources.1B: Quantitate approaches to climate change 1C: Deceleration of ng-scale starshot? What to take? Build communication (3D printer) on arrival? 2A: Fetch Y from Genbank. Code to find codons. 2B: Methods to understand Omes.2C: Odds of correct segregation of all human chromosomes if movement is random? 3A: Recode one (or 53) Y genes. Leu UUR to CUX3B: Consequences of such recoding? How to test?