Systematic discovery of natural CRISPR-Cas12a inhibitors

Science. 2018 Oct 12;362(6411):236-239. doi: 10.1126/science.aau5138. Epub 2018 Sep 6.


Cas12a (Cpf1) is a CRISPR-associated nuclease with broad utility for synthetic genome engineering, agricultural genomics, and biomedical applications. Although bacteria harboring CRISPR-Cas9 or CRISPR-Cas3 adaptive immune systems sometimes acquire mobile genetic elements encoding anti-CRISPR proteins that inhibit Cas9, Cas3, or the DNA-binding Cascade complex, no such inhibitors have been found for CRISPR-Cas12a. Here we use a comprehensive bioinformatic and experimental screening approach to identify three different inhibitors that block or diminish CRISPR-Cas12a-mediated genome editing in human cells. We also find a widespread connection between CRISPR self-targeting and inhibitor prevalence in prokaryotic genomes, suggesting a straightforward path to the discovery of many more anti-CRISPRs from the microbial world.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Bacterial Proteins / antagonists & inhibitors*
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • CRISPR-Cas Systems*
  • Cell Line
  • Computational Biology / methods
  • DNA Cleavage
  • Endonucleases / antagonists & inhibitors*
  • Gene Editing*
  • Genome, Bacterial
  • Humans
  • Moraxella / genetics*


  • Bacterial Proteins
  • Cas12a protein
  • Endonucleases