Optimizing ErCas12a for efficient gene editing in Arabidopsis thaliana

Area of Science:

• Molecular Biology
• Biotechnology
• Plant Science

Background:

• The ErCas12a (MAD7) nuclease, derived from Eubacterium rectale, presents an alternative to existing CRISPR/Cas12a systems due to distinct intellectual property.
• Its application in plants is limited by target sequence and temperature-dependent editing efficiency, particularly at lower cultivation temperatures.

Purpose of the Study:

• To enhance the gene editing efficiency of ErCas12a in plants through protein engineering.
• To develop a more effective and economically viable CRISPR/Cas system for plant genome engineering.

Main Methods:

• Protein engineering of ErCas12a by introducing amino acid substitutions analogous to those in enhanced AsCas12a variants.
• Testing editing efficiency of wild-type and mutated ErCas12a in Arabidopsis thaliana at varying temperatures.
• Evaluating off-target activity of the engineered variant.

Main Results:

• Mutations analogous to enhanced AsCas12a did not improve ErCas12a editing efficiency.
• Two specific mutations (V156R and K172R) individually showed detectable editing improvement.
• A combined mutation (imErCas12a) resulted in a several-fold increase in editing activity in Arabidopsis, with optimal performance at 28°C.
• The imErCas12a variant enabled editing of previously inaccessible targets without increased off-target effects.

Conclusions:

• The imErCas12a variant demonstrates significantly enhanced gene editing capabilities in plants, especially at optimal temperatures.
• This engineered nuclease offers an efficient and cost-effective alternative for plant genome engineering applications.
• imErCas12a expands the utility of CRISPR technology in plant biotechnology.