Cutting edge of chloroplast proteolysis.
Chloroplasts have a dynamic protein environment and, although proteases are presumably major contributors, the identities of these crucial regulatory proteins have only recently been revealed. There are defined proteases within each of the major chloroplast compartments: the ATP-dependent Clp and FtsH proteases in the stroma and stroma-exposed thylakoid membranes, respectively, the ATP-independent DegP proteases within the thylakoid lumen and on both sides of thylakoid membranes, and the SppA protease on the stromal side of the thylakoid. All four types are homologous to proteases characterized in bacteria, but most have many isomers in higher plants. With such diversity, the challenge is to link the mode of action of each protease to the chloroplast enzymes and regulatory proteins that it targets.
Adam
Zach
Z
Institute of Plant Sciences, The Hebrew University of Jerusalem, Rehovot, Israel. zach@agri.huji.ac.il
Clarke
Adrian K
AK
D049069:ATP-Dependent Proteases; D000251:Adenosine Triphosphatases / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D029681:Arabidopsis Proteins; D002736:Chloroplasts / Q000201:enzymology / Q000378:metabolism*; D010450:Endopeptidases / Q000378:metabolism*; D006360:Heat-Shock Proteins / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism; D012697:Serine Endopeptidases / Q000378:metabolism; D020524:Thylakoids / Q000201:enzymology / Q000378:metabolism
D049069:ATP-Dependent Proteases; D000251:Adenosine Triphosphatases; D000255:Adenosine Triphosphate; D029681:Arabidopsis Proteins; D010450:Endopeptidases; D006360:Heat-Shock Proteins; D008565:Membrane Proteins; D010940:Plant Proteins; D012697:Serine Endopeptidases; C423318:DegP2 protein, Arabidopsis; C436319:SPPA protein, Arabidopsis; C402651:AT2G30950 protein, Arabidopsis