Abstract
Thioredoxin (Trx) is a small ubiquitous protein that regulates a number of phenomena through formation or dissociation of a disulphide bridge in the target enzyme. Cytosolic thioredoxin has been reported to regulate several membrane proteins that involve in the self-incompatibility and in the innate immunity of plant so far. However, a membrane protein involved in the redox cascade is still poorly understood.
To uncover a whole picture of membrane proteins involved in the redox cascade, we screened target proteins of thioredoxin in plasma membranes from the suspension culture of Arabidopsis thaliana. The resulting proteins were identified by MALDI-TOF/TOF MS analysis. A list of potential targets for thioredoxin contained some signaling molecules, such as membrane-associated protein kinases. We prepared some recombinant proteins of the molecules and analyzed their redox regulation in vitro. The result allows us to presume a mechanism for redox regulation of the membrane signaling molecule in plant cells.
