In vivo analysis of protein-protein interactions within the two-component signaling network in Arabidopsis.
|Year of publication||2010|
|MU Faculty or unit|
|Description||Two-component systems (TCS) belong to important sensing/response mechanisms in higher plants. This mechanism is used to perceive and transduce the signal of cytokinin and ethylene, plant hormones regulating variety of processes of growth and development. Function and composition of TCS have been intensively studied mostly in Arabidopsis thaliana. In this model plant TCS are composed of hybrid histidine kinases (AHKs, 8 genes), histidine-containting phosphotransfer proteins (AHPs, 6 genes) and response regulators (ARRs, 24 genes), that are biochemically linked by His-to-Asp phosphorelay. The specific interactions between AHPs and the receiver domains of AHKs could represent a potent mechanism how the specificity of cellular responses to different signals is achieved within the complex two-component signaling network.In this study the interactions between all receiver domains of AHKs and all six AHPs were analyzed in vivo. Using the modified MatchmakerTM yeast two-hybrid system (Clontech) were confirmed known and revealed novel interactions between these two families. As an independent method for the results verification was carried out Bimolecular Fluorescence Complementation analysis (BiFC) in transiently transformed tobacco leaves. Quantification of the fluorescence intensity in this analysis has also shown the differences between affinities of the AHPs to the receiver domains. We revealed that all receiver domains of AHKs interact with a specific set of AHPs. AHP5 interacts with each of the receiver domains, other AHPs interact more specifically. Receiver domains of AHK1, AHK5, CKI1 and ethylene receptors interact with the AHPs with higher affinity then the cytokinin receptors.|