Precision Control of CRISPR-Cas9 Using Small Molecules and Light

Biochemistry. 2019 Jan 29;58(4):234-244. doi: 10.1021/acs.biochem.8b01202. Epub 2019 Jan 22.


The CRISPR (clustered regularly interspaced short palindromic repeat)-Cas system is an adaptive immune system of bacteria that has furnished several RNA-guided DNA endonucleases (e.g., Cas9) that are revolutionizing the field of genome engineering. Cas9 is being used to effect genomic alterations as well as in gene drives, where a particular trait may be propagated through a targeted species population over several generations. The ease of targeting catalytically impaired Cas9 to any genomic loci has led to development of technologies for base editing, chromatin imaging and modeling, epigenetic editing, and gene regulation. Unsurprisingly, Cas9 is being developed for numerous applications in biotechnology and biomedical research and as a gene therapy agent for multiple pathologies. There is a need for precise control of Cas9 activity over several dimensions, including those of dose, time, and space in these applications. Such precision controls, which are required of therapeutic agents, are particularly important for Cas9 as off-target effects, chromosomal translocations, immunogenic response, genotoxicity, and embryonic mosaicism are observed at elevated levels and with prolonged activity of Cas9. Here, we provide a perspective on advances in the precision control of Cas9 over aforementioned dimensions using external stimuli (e.g., small molecules or light) for controlled activation, inhibition, or degradation of Cas9.

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.
  • Review

MeSH terms

  • CRISPR-Associated Protein 9 / antagonists & inhibitors
  • CRISPR-Associated Protein 9 / genetics
  • CRISPR-Associated Protein 9 / metabolism
  • CRISPR-Cas Systems* / drug effects
  • Gene Expression Regulation
  • Genetic Engineering / methods*
  • Light
  • RNA, Guide
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Small Molecule Libraries / chemistry
  • Small Molecule Libraries / pharmacology*
  • Tacrolimus Binding Proteins / genetics
  • Tacrolimus Binding Proteins / metabolism


  • RNA, Guide
  • Recombinant Proteins
  • Small Molecule Libraries
  • CRISPR-Associated Protein 9
  • Tacrolimus Binding Proteins