Quality control of photosystemII: Light- and temperature- stress-induced accumulation of an FtsH protease in the wild-type cells of Synechocystis PCC6803

Abstract

In a cyanobacterium Synechocystis PCC 6803, an FtsH protease (FtsH2, slr0228) is involved in the proteolysis of the D1 protein damaged by light stress and heat stress. Thus, the FtsH protease is essential for cell growth under these stress conditions.
To see if the synthesis of the protease is stimulated under the stress conditions, We carried out Western blot analysis to estimate the amount of FtsH in the wild-type cells subjected to moderate heat stress (42^oC, 2h), light stress (1000uEm^-2s^-1, 2h), and low temperature stress (4^oC, 18h) conditions. The antibody against DS9 protein corresponding to an FtsH protease identified in tobacco was used for the immunoblotting. We found that under these stress conditions, the level of the FtsH protease in the cells increased by 5-40 % compared with the cells grown under normal conditions.