title: Deg/HtrA proteases as components of a network for photosystem II quality control in chloroplasts and cyanobacteria.
abstract: Organisms that perform oxygenic photosynthesis are subjected to photoinhibition of their photosynthetic function when exposed to excessive illumination. The main target of photoinhibition is the D1 protein in the reaction center of the photosystem II complex. Rapid degradation of photodamaged D1 protein and its replacement by a de novo synthesized functional copy represent an important repair mechanism crucial for cell survival under light stress conditions. This review summarizes the literature on the ATP-independent Deg/HtrA family of serine endopeptidases in cyanobacteria and chloroplasts of higher plants, and discusses their role in D1 protein degradation. We propose that Deg/HtrA proteases are part of a larger network of enzymes that ensure protein quality control, including photosystem II, in plants and cyanobacteria.
authors.affiliation: Department of Plant Physiology and Biochemistry, University of Konstanz, Universitätsstrasse 10, D-78457 Konstanz, Germany.
authors.forename: Pitter F
authors.initials: PF
authors.lastname: Huesgen
authors.forename: Holger
authors.initials: H
authors.lastname: Schuhmann
authors.forename: Iwona
authors.initials: I
authors.lastname: Adamska
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D002736:Chloroplasts / Q000201:enzymology*; D000458:Cyanobacteria / Q000201:enzymology*; D010447:Peptide Hydrolases / Q000378:metabolism*; D010788:Photosynthesis; D045332:Photosystem II Protein Complex / Q000378:metabolism*; D010944:Plants / Q000378:metabolism; D046939:Synechocystis / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D045332:Photosystem II Protein Complex; C422369:photosystem II, psbA subunit; D010447:Peptide Hydrolases