Methods of Redox Signaling by Plant Thioredoxins

Studies of redox signaling have to take into account the highly reductive intracellular environment and the lability of redox changes in regulatory proteins. Thus, befitting methodology suited to trapping the authentic state in vivo is required. This is particularly relevant in plants where the abundance of redox signaling proteins makes it difficult to discern the cellular function of a specific protein. In this chapter, we present two complementing methods designed first to characterize the redox state in vivo of thioredoxin family proteins and second to capture their in vivo targets. These methods can be used to look at the activity and target proteins of a specific protein under different physiological conditions and in different cellular compartments. Furthermore, as demonstrated here, they can be used to compare the activity of different family members under the same conditions and thus shed light on their general and unique roles.