Article of Significant Interest in This Issue

摘要

In bacteria, the Lon protease destroys poor-quality polypeptides to prevent the toxic accumulation of misfolded proteins. However, Lon also degrades essential regulatory proteins, such as DnaA in Caulobacter crescentus; hence, activity must be carefully monitored. Barros et al. (e00344-20) show that the Lon protease is itself degraded in vivo. This process requires active Lon proteases and requires carboxy-terminal residues also found in various Lon orthologs. In Caulobacter, expression of stabilized Lon drastically reduces DnaA levels, leading to cell death. They suggest that this posttranslational control balances the requirement for Lon with the toxicity associated with unconstrained proteolysis.