Abstract
Thioredoxin (Trx) is a small ubiquitous protein, which regulates a number of phenomena through formation or reduction of a disulphide bridge in the target enzyme. Possible target proteins have been identified in plant cells by the latest approaches with Thioredoxin affinity chromatography. However, a membrane protein involved in the redox cascade has not been well known, although they may play an essential role in the redox signaling.
To elucidate target proteins of cytosolic thioredoxin in plant membranes, we prepared a post-mitochondrial fraction from suspension culture of Arabidopsis thaliana, and then solubilized proteins were subjected to the method of Thioredoxin affinity chromatography. The resulting proteins were identified by MALDI-TOF/TOF MS analysis, N-terminal amino acid sequencing, and immunoblotting using specific antibodies against plant membrane proteins. We present a list of potential targets for thioredoxin, which allow us to presume the physiological meaning of the redox regulation in plant cells.
