Informace o publikaci
Study of the Receiver and Receiver-like Domain Relationship in Cytokinin Receptor of Arabidopsis thaliana
| Autoři | |
|---|---|
| Rok publikování | 2013 |
| Druh | Konferenční abstrakty |
| Fakulta / Pracoviště MU | |
| Citace | |
| Popis | Cytokinin (CK) signaling is one of the pathways mediated by multistep phosphorelay (MSP) in plants. In the MSP of Arabidopsis thaliana, Arabidopsis histidine kinases (AHKs) act as receptors initiating the pathway and interact with Arabidopsis histidine-containing proteins (AHPs), thus transferring the signal farther in the cascade. For the signal transduction through the cascade, the domain composition of the MSP elements is crucial. Recently it was reported that the receiver domain of one of the Arabidopsis sensor histidine kinases CKI1 is sufficient and necessary for the specific interaction of CKI1 with AHPs. Here we performed an extensive study of the individual domains of CK receptor AHK4 in mediating interactions with AHPs. Thorough bioinformatic analysis of the AHK4 aa sequence using similarity search was carried out to refine the precise borders of AHK4 individual domains. SMART and PROSITE databases for primary and secondary structure analysis were used to identify similarities within receiver and receiver-like domains of other AHKs and the results were manually refined. Moreover, we modeled individual structures of the receiver and receiver-like domain of AHK4 (AHK4 RD and AHK4 RLD , respectively) employing their homology with solved structure of bacterial response regulator receiver domain CheY in order to see possible differences in the structure and to predict potential interaction interfaces. The structural predictions were used to design recombinant DNA constructs for protein-protein interaction experiments. Intriguingly, by yeast two-hybrid analysis we revealed that not only AHK4 RD is substantial for the interaction with AHPs but we found out that the interaction can be suppressed by AHK4 RLD . We propose that AHK4 RLD has a (negative) regulatory function in the process of molecular recognition of the downstream signaling partners and we experimentally demonstrated that this function can be provided by the heterodimerization of AHK4 RD with AHK4RLD, either intra- or intermolecularly. The structural prediction-based model of this regulatory role will be presented. |