Researchers at the Broad Institute of MIT and Harvard and the McGovern Institute for Brain Research at MIT have engineered changes to the revolutionary CRISPR-Cas9 genome editing system that significantly cut down on “off-target” editing errors. The refined technique addresses one of the major technical issues in the use of genome editing.
The CRISPR-Cas9 system works by making a precisely targeted modification in a cell’s DNA. The protein Cas9 alters the DNA at a location that is specified by a short RNA whose sequence matches that of the target site. While Cas9 is known to be highly efficient at cutting its target site, a major drawback of the system has been that, once inside a cell, it can bind to and cut additional sites that are not targeted. This has the potential to produce undesired edits that can alter gene expression or knock a gene out entirely, which might lead to the development of cancer or other problems. In a paper published today in Science, Feng Zhang and his colleagues report that changing three of the approximately 1,400 amino acids that make up the Cas9 enzyme from S. pyogenes dramatically reduced “off-target editing” to undetectable levels in the specific cases examined.
Zhang and his colleagues used knowledge about the structure of the Cas9 protein to decrease off-target cutting. DNA, which is negatively charged, binds to a groove in the Cas9 protein that is positively charged. Knowing the structure, the scientists were able to predict that replacing some of the positively charged amino acids with neutral ones would decrease the binding of “off target” sequences much more than “on target” sequences.
After experimenting with various possible changes, Zhang’s team found that mutations in three amino acids dramatically reduced “off-target” cuts. For the guide RNAs tested, “off-target” cutting was so low as to be undetectable.
The newly-engineered enzyme, which the team calls “enhanced” S. pyogenes Cas9, or eSpCas9, will be useful for genome editing applications that require a high level of specificity. The Zhang lab is immediately making the eSpCas9 enzyme available for researchers worldwide. The team believes the same charge-changing approach will work with other recently described RNA-guided DNA targeting enzymes, including Cpf1, C2C1, and C2C3, which Zhang and his collaborators reported on earlier this year.
The prospect of rapid and efficient genome editing raises many ethical and societal concerns, says Zhang, who is speaking this morning at the International Summit on Gene Editing in Washington, DC. “Many of the safety concerns are related to off-target effects,” he said. “We hope the development of eSpCas9 will help address some of those concerns, but we certainly don’t see this as a magic bullet. The field is advancing at a rapid pace, and there is still a lot to learn before we can consider applying this technology for clinical use.”
The Latest on: CRISPR-Cas9 genome editing
via Google News
The Latest on: CRISPR-Cas9 genome editing
- Gene Editing Tools Market is expected to grow at an approximate CAGR of 18% over 2019-2029on January 26, 2021 at 2:28 am
Market players are extending their product portfolios and are making investments to fulfill the research requirements. FMI in its recent study on the ...
- Spotting Every Needle in the Haystack: CRISPeR Gene Editing for DNA with Lone Mutationson January 25, 2021 at 5:36 am
The quest to change the very nature of being, has driven philosophical and metaphysical debates for ages. Now, with the advent of ...
- Microbiosci Launches Complete Solutions for Genome Editing with CRISPR Technologyon January 22, 2021 at 2:41 pm
(MENAFN - GetNews) Recently Microbiosci announced the release of its one-stop CRISPR /Cas9-mediated Genome Editing Service that can be applied in the process of genome editing. New York ...
- Microbiosci Launches Complete Solutions for Genome Editing with CRISPR Technologyon January 22, 2021 at 10:07 am
Microbiosci announced the release of its one-stop CRISPR /Cas9-mediated Genome Editing Service that can be applied in the process of genome editing. New York, ...
- Researcher expands plant genome editing with newly engineered variant of CRISPR-Cas9on January 22, 2021 at 9:46 am
Alongside Dennis van Engelsdorp, associate professor at the University of Maryland (UMD) in Entomology named for the fifth year in a row for his work in honey bee and pollinator health, Yiping Qi, ...
- UMD researcher expands plant genome editing with newly engineered variant of CRISPR-Cas9on January 22, 2021 at 8:25 am
Recently named a Web of Science 2020 Highly Cited Researcher, Yiping Qi of the University of Maryland already has a new high-profile publication in 2021 introducing SpRY, a newly engineered variant of ...
- Plant genome editing expanded with newly engineered variant of CRISPR-Cas9on January 20, 2021 at 4:00 pm
Scientists have created a newly engineered variant of the famed gene editing tool CRISPR-Cas9. SpRY removes the barriers of what can and can't be targeted for gene editing, making it possible for the ...
- 7 CRISPR Stocks for the Future of Medicineon January 15, 2021 at 8:12 pm
Between these seven genetic editing pioneers, you have the widest exposure to the biggest scientific breakthrough of the century.
- One step closer to CRISPR-Cas9 cancer therapieson January 15, 2021 at 5:16 am
Cas9 cancer therapies. Once CRISPR-Cas9 genome editing technology became available, scientists worldwide began using it to learn more ab ...
via Bing News