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Massively parallel Cas13 screens reveal principles for guide RNA design

Abstract

Type VI CRISPR enzymes are RNA-targeting proteins with nuclease activity that enable specific and robust target gene knockdown without altering the genome. To define rules for the design of Cas13d guide RNAs (gRNAs), we conducted massively parallel screens targeting messenger RNAs (mRNAs) of a green fluorescent protein transgene, and CD46, CD55 and CD71 cell-surface proteins in human cells. In total, we measured the activity of 24,460 gRNAs with and without mismatches relative to the target sequences. Knockdown efficacy is driven by gRNA-specific features and target site context. Single mismatches generally reduce knockdown to a modest degree, but spacer nucleotides 15–21 are largely intolerant of target site mismatches. We developed a computational model to identify optimal gRNAs and confirm their generalizability, testing 3,979 guides targeting mRNAs of 48 endogenous genes. We show that Cas13 can be used in forward transcriptomic pooled screens and, using our model, predict optimized Cas13 gRNAs for all protein-coding transcripts in the human genome.

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Fig. 1: Pooled CRISPR RfxCas13d GFP knockdown tiling screen.
Fig. 2: RfxCas13d on-target gRNA prediction model.
Fig. 3: Improvement of RfxCas13d on-target gRNA prediction model with tiling screens over endogenous transcripts.

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Data availability

Screen data have been deposited at the Gene Expression Omnibus (https://www.ncbi.nlm.nih.gov/geo/) with the accession no. GSE142675. All code and software to reproduce our entire analyses are available on our gitlab repository (https://gitlab.com/sanjanalab/cas13). Moreover, we provide precomputed gRNA predictions targeting all protein-coding transcripts in the human genome on our web-based repository (https://cas13design.nygenome.org). Other data and materials that support the findings of this research are available from the corresponding author upon reasonable request.

Code availability

The predictive on-target model as well as all code for the analyses presented in the letter is available on our gitlab repository (https://gitlab.com/sanjanalab/cas13).

References

  1. Abudayyeh, O. O. et al. C2c2 is a single-component programmable RNA-guided RNA-targeting CRISPR effector. Science 353, aaf5573 (2016).

  2. Abudayyeh, O. O. et al. RNA targeting with CRISPR–Cas13. Nature 550, 280–284 (2017).

    Article  Google Scholar 

  3. East-Seletsky, A. et al. Two distinct RNase activities of CRISPR-C2c2 enable guide-RNA processing and RNA detection. Nature 538, 270–273 (2016).

    Article  CAS  Google Scholar 

  4. Smargon, A. A. et al. Cas13b Is a type VI-B CRISPR-associated RNA-guided RNase differentially regulated by accessory proteins Csx27 and Csx28. Mol. Cell 65, 618–630 (2017).

    Article  CAS  Google Scholar 

  5. Konermann, S. et al. Transcriptome engineering with RNA-targeting type VI-D CRISPR effectors. Cell 173, 665–676 (2018).

    Article  CAS  Google Scholar 

  6. Yan, W. X. et al. Cas13d Is a compact RNA-targeting type VI CRISPR effector positively modulated by a WYL-domain-containing accessory protein. Mol. Cell 70, 327–339 (2018).

    Article  CAS  Google Scholar 

  7. Freije, C. A. et al. Programmable inhibition and detection of RNA viruses using Cas13. Mol. Cell 76, 1–12 (2019).

    Article  Google Scholar 

  8. Poosala, P., Lindley, S. R., Anderson, K. M. & Anderson, D. M. Targeting toxic nuclear RNA foci with CRISPR-Cas13 to treat myotonic dystrophy. Preprint at bioRxiv https://doi.org/10.1101/716514 (2019).

  9. Mahas, A., Aman, R. & Mahfouz, M. CRISPR-Cas13d mediates robust RNA virus interference in plants. Genome Biol. 20, 1–16 (2019).

    Article  Google Scholar 

  10. Kushawah, G. et al. CRISPR-Cas13d induces efficient mRNA knock-down in animal embryos. Preprint at bioRxiv https://doi.org/10.1101/2020.01.13.904763 (2020).

  11. Gootenberg, J. S. et al. Nucleic acid detection with CRISPR-Cas13a/C2c2. Science 356, 438–442 (2017).

    Article  CAS  Google Scholar 

  12. Gootenberg, J. S. et al. Multiplexed and portable nucleic acid detection platform with Cas13, Cas12a, and Csm6. Science 360, 439–444 (2018).

    Article  CAS  Google Scholar 

  13. Cox, D. B. T. et al. RNA editing with CRISPR-Cas13. Science 358, 1019–1027 (2017).

    Article  CAS  Google Scholar 

  14. Li, J.et al. Targeted mRNA demethylation using an engineered dCas13b-ALKBH5 fusion protein. Preprint at bioRxiv https://doi.org/10.1101/614859 (2019).

  15. Wang, H. et al. CRISPR-mediated live imaging of genome editing and transcription. Science 365, 2–6 (2019).

    Google Scholar 

  16. Yang, L.-Z. et al. Dynamic imaging of RNA in living cells by CRISPR-technology. Mol. Cell 76, 1–17 (2019).

    Article  Google Scholar 

  17. Jillette, N. & Cheng, A. W. CRISPR artificial splicing factors. Preprint at bioRxiv https://doi.org/10.1101/431064 (2018).

  18. Anderson, K. M., Poosala, P., Lindley, S. R. & Anderson, D. M. Targeted cleavage and polyadenylation of RNA by CRISPR-Cas13. Preprint at bioRxiv https://doi.org/10.1101/531111 (2019).

  19. Meeske, A. J., Nakandakari-Higa, S. & Marraffini, L. A. Cas13-induced cellular dormancy prevents the rise of CRISPR-resistant bacteriophage. Nature 570, 241–245 (2019).

    Article  CAS  Google Scholar 

  20. Meeske, A. J. & Marraffini, L. A. RNA guide complementarity prevents self-targeting in type VI CRISPR systems. Mol. Cell 71, 791–801 (2018).

    Article  CAS  Google Scholar 

  21. Liu, L. et al. The molecular architecture for RNA-guided RNA cleavage by Cas13a. Cell 170, 714–720 (2017).

    Article  CAS  Google Scholar 

  22. Tambe, A., East-seletsky, A., Knott, G. J., Connell, M. R. O. & Doudna, J. A. RNA binding and HEPN-nuclease activation are decoupled in CRISPR-Cas13a. Cell Rep. 24, 1025–1036 (2018).

    Article  CAS  Google Scholar 

  23. Zhang, C. et al. Structural basis for the RNA-guided ribonuclease activity of CRISPR-Cas13d. Cell 175, 212–223 (2018).

    Article  CAS  Google Scholar 

  24. Zhang, B. et al. Two HEPN domains dictate CRISPR RNA maturation and target cleavage in Cas13d. Nat. Commun. 10, 2544 (2019).

  25. Konermann, S. et al. Genome-scale transcriptional activation by an engineered CRISPR–Cas9 complex. Nature 517, 583–588 (2015).

    Article  CAS  Google Scholar 

  26. Replogle, J. M.et al. Direct capture of CRISPR guides enables scalable, multiplexed, and multi-omic Perturb-seq. Preprint at bioRxiv https://doi.org/10.1101/503367 (2018).

  27. Doench, J. G. et al. Rational design of highly active sgRNAs for CRISPR–Cas9-mediated gene inactivation. Nat. Biotechnol. 32, 1262–1267 (2014).

    Article  CAS  Google Scholar 

  28. McFarland, J. M. et al. Improved estimation of cancer dependencies from large-scale RNAi screens using model-based normalization and data integration. Nat. Commun. 9, 1–13 (2018).

    Article  CAS  Google Scholar 

  29. Doench, J. G. et al. Optimized sgRNA design to maximize activity and minimize off-target effects of CRISPR–Cas9. Nat. Biotechnol. 34, 184–191 (2016).

    Article  CAS  Google Scholar 

  30. Briese, M. et al. A systems view of spliceosomal assembly and branchpoints with iCLIP. Nat. Struct. Mol. Biol. 26, 930–940 (2019).

    Article  CAS  Google Scholar 

  31. Saulière, J. et al. CLIP-seq of eIF4AIII reveals transcriptome-wide mapping of the human exon junction complex. Nat. Struct. Mol. Biol. 19, 1124–1131 (2012).

    Article  Google Scholar 

  32. Hauer, C. et al. Exon junction complexes show a distributional bias toward alternatively spliced mRNAs and against mRNAs coding for ribosomal proteins. Cell Rep. 16, 1588–1603 (2016).

    Article  CAS  Google Scholar 

  33. Sanjana, N. E., Shalem, O. & Zhang, F. Improved vectors and genome-wide libraries for CRISPR screening. Nat. Methods 11, 783–784 (2014).

    Article  CAS  Google Scholar 

  34. Lorenz, R. et al. ViennaRNA package 2.0. Algorithms Mol. Biol. 6, 26 (2011).

    Article  Google Scholar 

  35. Shalem, O. et al. Genome-scale CRISPR-Cas9 knockout screening in human cells. Science 343, 84–88 (2014).

    Article  CAS  Google Scholar 

  36. Langmead, B., Trapnell, C., Pop, M. & Salzberg, S. L. Ultrafast and memory-efficient alignment of short DNA sequences to the human genome. Genome Biol. 10, 212 (2009).

  37. Love, M. I., Huber, W. & Anders, S. Moderated estimation of fold change and dispersion for RNA-seq data with DESeq2. Genome Biol. 15, 550 (2014).

    Article  Google Scholar 

  38. Leek, J. T., Johnson, W. E., Parker, H. S., Jaffe, A. E. & Storey, J. D. The sva package for removing batch effects and other unwanted variation in high-throughput experiments. Bioinformatics 28, 882–883 (2012).

    Article  CAS  Google Scholar 

  39. Kolde, R., Laur, S., Adler, P. & Vilo, J. Robust rank aggregation for gene list integration and meta-analysis. Bioinformatics 28, 573–580 (2012).

    Article  CAS  Google Scholar 

  40. Agarwal, V., Subtelny, A. O., Thiru, P., Ulitsky, I. & Bartel, D. P. Predicting microRNA targeting efficacy in Drosophila. Genome Biol. 19, 1–23 (2018).

    Article  Google Scholar 

  41. Krueger, J. & Rehmsmeier, M. RNAhybrid: microRNA target prediction easy, fast and flexible. Nucleic Acids Res. 34, 451–454 (2006).

    Article  Google Scholar 

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Acknowledgements

We thank the entire Sanjana laboratory for support and advice. We thank R. Satija for critical feedback. We also thank D. Knowles for discussion about model building and M. Zaran for assistance with the web-tool server. N.E.S. is supported by New York University and New York Genome Center startup funds, National Institutes of Health (NIH)/National Human Genome Research Institute (grant nos. R00HG008171, DP2HG010099), NIH/National Cancer Institute (grant no. R01CA218668), Defense Advanced Research Projects Agency (grant no. D18AP00053), the Sidney Kimmel Foundation, the Melanoma Research Alliance, and the Brain and Behavior Foundation. A.M.-M. is supported by a CONACyT-Mexico Fellowship (no. 412653).

Author information

Authors and Affiliations

Authors

Contributions

H.H.W and N.E.S conceived the project. H.H.W., N.E.S and A.M.-M. designed the experiments. A.M.-M. and H.H.W. performed and analyzed the experiments. H.H.W. analyzed the screen data, and built the gRNA prediction software and online repository. X.G., M.L. and Z.D. helped with post-screen validation experiments. N.E.S. supervised the work. H.H.W. and N.E.S. wrote the manuscript with input from all the authors.

Corresponding author

Correspondence to Neville E. Sanjana.

Ethics declarations

Competing interests

The New York Genome Center and New York University have applied for patents relating to the work in this article. N.E.S. is an adviser to Vertex.

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Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Materials

Supplementary Figs. 1–11, Tables 1–7 and Notes 1 and 2.

Reporting Summary

Supplementary Data 1

Guide RNA enrichments of sorted populations over input populations.

Supplementary Data 2

Combined on-target model input including all features.

Supplementary Data 3

Guide RNA predictions for protein-coding transcripts in GENCODE.

Supplementary Data 4

Oligonucleotide information.

Supplementary Data 5

Statistics of processed gRNA and cell numbers.

Supplementary Data 6

Sequencing read processing statistics.

Supplementary Data 7

Raw gRNA counts.

Supplementary Data 8

Final gRNA counts (after normalization; batch correction; outlier removal).

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Wessels, HH., Méndez-Mancilla, A., Guo, X. et al. Massively parallel Cas13 screens reveal principles for guide RNA design. Nat Biotechnol 38, 722–727 (2020). https://doi.org/10.1038/s41587-020-0456-9

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