Poster: Regulation of gene expression
Abs #
760: The protein-protein interaction network of the cytokinin signal transduction pathway in Arabidopsis thaliana
In recent years it has been shown that the hormone cytokinin (Ck) is recognized in Arabidopsis by three histidine kinases and that the signal is transmitted by members of the two component system (TCS), a signalling pathway well established in bacteria and lower eukaryotes. Analysis of the Arabidopsis genome reveals, in addition to the three cytokinin binding histidine kinase receptors, five phosphotransmitter proteins and a total of 22 response regulators. It is known that the Ck-signal is transduced in the TCS via phospho-relay involving protein-protein interaction, and a few of those interactions have been shown. However, so far no comprehensive interaction network, necessary for understanding this signalling pathway, has been established. The primary aim of our project is to test all 30 components involved in Ck signalling for interaction with each other, using the yeast-two hybrid system to elucidate the network. In a second approach, we are attempting to extend the signalling network beyond the TCS by screening for interacting partners of the Arabidopsis proteome in vivo and by combining co-affinity purification and mass spectrometry. First results of these experiments will be presented.
