Scientists Introduce New 'Editing Genomes' for Precise Genome Engineering
FREMONT, CA: Scientists have found a substitute for the CRISPR (Clustered regularly interspaced short palindromic repeats) Cas9 system, with simple and precise genome engineering. The new system can be used to edit the genomes of human cells. The Cas9 protein of the CRISPR is replaced with Cpf1 which is a single RNA guided endonuclease.
“It is indeed a new system that is substantially different than the previously known one. There is a niche market for a collection of different proteins so that cuts can be placed anywhere in the genome,” says Dan Voytas, a genome-editing researcher, University of Minnesota.
CRISPR is based on a natural system used by a kind of bacteria to defend against viruses by keeping them around so it can protect itself next time the virus attacks. This comprises the first part of CRISPR while the other is a set of defense mechanism called Cas (CRISPR associated proteins) that can cut the DNA and slice the invading viruses.
The new Cpf1 system sets itself apart from the previous Cas9 in many ways that include its natural form, which consists of only one RNA unlike the previous Cas9 that required two RNAs for cutting. In addition, the method of cutting DNA by Cpf1 differs from the Cas9 as it cuts the DNA strands leaving short overhangs on the exposed ends that help researchers to integrate DNA pieces efficiently compared to the previous Cas9 that left the DNA strands blunt after cutting leading to mutations. Moreover, if the strand becomes mutated at the cut site, then there is a possibility to re cut the strand through Cpf1 allowing multiple opportunities for editing. The Cpf1 system recognizes different PAM sequences from those of Cas9 that can benefit in targeting specific genomes like malaria parasites.