| Description |
Farrerol, a natural flavanone isolated from the medicinal herb Rhododendron dauricum L., plays multiple roles in different biological contexts. Our previous study demonstrated that farrerol utilizes homologous recombination (HR) to promote DNA repair and improve genome-editing efficiency. However, the specific protein that farrerol directly targets to regulate HR and the underlying molecular mechanisms have not been determined. Using LiP-SMap combined with a BIAcore assay, we identified that the deubiquitinase UCHL3, which regulates HR repair by deubiquitinating and activating the recombinase RAD51, is the direct target of farrerol (Kd = 36.73 nM). Cocrystallization experiments and cellular thermal shift assays revealed that two amino acid residues, K187 and R215, were crucial for the direct binding of farrerol to UCHL3. Furthermore, we demonstrated that farrerol enhanced the deubiquitinase activity of UCHL3 to promote RAD51 deubiquitination, thereby improving HR repair. Importantly, we found that farrerol promoted the efficiency of somatic cell nuclear transfer (SCNT), in which effective HR is critical. Ablating UCHL3 significantly attenuated farrerol-mediated stimulation in HR and the development of SCNT embryos. In summary, we identified farrerol as the first activator of the deubiquitinase UCHL3, highlighted the importance of HR in SCNT reprogramming and provided a more feasible method to promote SCNT efficiency when compared to other methods. |
