Regulation of a AAA+ protease

BSF startup # 2009405 report The goal of our research entitled “The regulation mechanism of a AAA+ protease by its substrates” was to elucidate how substrates allosterically regulate the activity of the Lon AAA+ protease. We proposed to study the allosteric regulation mechanism by studying Lon mutants with specific properties using advanced biochemical and genetic approaches. Our findings indicate individual AAA+ proteases can differ substantially in their ability to unfold native proteins, and the direction of degradation can have a large influence on unfolding activity. Presumably, the degradation tags of substrates that are difficult to unfold have evolved to optimize targeting to AAA+ proteases that can best unfold these domains.

Different AAA+ proteases have also apparently evolved to allow more efficient degradation of certain types of protein domains. For example, an N-tagged or a C-tagged protein similar to GFP would be a very poor Lon substrate but a good ClpAP substrate. By contrast, a C-tagged protein with properties similar to titinI27 would be expected to be a good Lon substrate but a very poor ClpAP substrate. These findings were summarizes in a manuscript that is now published in Protin Science scientific journal. (Gur E, et al., 2012)