Abstract

Members of the DegP/HtrA protease family are widespread in nature and play an important role in proteolysis of misfolded and damaged proteins. The cyanobacterium Synechocystis sp. FCC 6803 contains three Deg proteases, HhoA (Sll1679), HhoB (Sll1427) and HtrA (Slr1204). Using the proteomic or metabolomic approach we investigated a triple deletion mutant (Delta deg) exposed to light or temperature stress. To cope with the stress conditions the triple mutant reduces its energy metabolism and stress-related proteins are induced to protect the cells. Additionally the co-expression of the genes encoding the three proteases with other genes in Synechocystis sp. PCC 6803 was analyzed. While HhoA seems to be involved in house-keeping processes related to protein (re)folding, protein clearance and signaling, the hhoB expression cluster is dominated by genes encoding periplasmic proteins linked to metabolism or signal transduction pathways. The htrA expression pattern is similar to that of genes encoding proteins of the electron transport chain, iron- and nitrogen metabolism. Our integrative approach indicates significant rearrangements in cells depleted of the Deg/HtrA proteases when exposed to stress, both, in the cytoplasmic and extracytoplasmic space. (C) 2012 Elsevier B.V. All rights reserved.

Keywords

Synechocystis sp PCC 6803; Heat shock; High light; Deg/HtrA proteases; Proteome; Metabolites

Published in

Journal of Proteomics
2013, volume: 78, pages: 294-311
Publisher: ELSEVIER SCIENCE BV

Authors' information