Expression and purification of unstable proteins using an ASK-assisted system
Ubiquitin-mediated protein degradation is important in many plant processes (growth, development, responses to stress) but little is known about F-box proteins, a key component of the SCF (SKP1-CUL1-F-box protein) E3 ubiquitin ligase complex, due to their unstable protein structures. Li et al. investigated the use of ASK1 (Arabidopsis SKP1-like1, which binds to SCF E3 ubiquitin ligase complexes) to aid in the expression and purification of F-box proteins (COI1, TIR1, SLY1 and EBF1) in a baculovirus–insect cell expression system. They show that ASK1 improves the expression of F-box proteins, that ASK1 is essential for maintaining the bioactivity of the F-box proteins, and that different ASK proteins have different effects on F-box protein expression. The authors also describe a novel F-box protein purification process to generate high purity F-box proteins. (Summary by Julia Miller) Plant J. 10.1111/tpj.13708