Thioredoxin targets of the plant chloroplast lumen and their implications for plastid function.

The light-dependent regulation of stromal enzymes by thioredoxin (Trx)-catalysed disulphide/dithiol exchange is known as a classical mechanism for control of chloroplast metabolism. Recent proteome studies show that Trx targets are present not only in the stroma but in all chloroplast compartments, from the envelope to the thylakoid lumen. Trx-mediated redox control appears to be a common feature of important pathways, such as the Calvin cycle, starch synthesis and tetrapyrrole biosynthesis.