VivosX is an in vivo disulfide crosslinking approach that utilizes a pair of engineered cysteine residues which can form a disulfide bond upon treatment with a cell permeable thiol oxidant. The disulfide bonded proteins are a measure of the physical interaction between the two proteins. Chitra Mohan and colleagues used VivosX to determine global histone H2A.Z occupancy in yeast and detect the different chromatin states of H2A.Z in both yeast and human cells. VivosX is a simple technique and can be used to gain insight into site – specific interaction between two proteins inside the cells.
Puri et al demonstrate that the highly conserved heat-shock protein Q (HspQ) allosterically primes the AAA+ Lon protease to achieve temporally enhanced substrate selectivity. Specific HspQ-Lon interactions increase Lon’s ability to recognize target substrates among a diverse pool of proteins.
- HspQ is a unique specificity-enhancing factor of the AAA+ Lon protease
- Multipartite HspQ-Lon interactions are required to allosterically activate Lon
- HspQ enhances the degradation of divers folded and unfolded Lon substrates
- Lon has multiple substrate recognition sites that could be simultaneously engaged