Destabilization of interaction between cytokinin signaling intermediates AHP1 and ARR4 modulates Arabidopsis development
© 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.
| Veröffentlicht in: | The New phytologist. - 1979. - 206(2015), 2 vom: 02. Apr., Seite 726-37 |
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| Weitere Verfasser: | , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2015
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| Zugriff auf das übergeordnete Werk: | The New phytologist |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Arabidopsis histidine phosphotransfer protein 1 (AHP1) Arabidopsis response regulator 4 (ARR4) cytokinin signaling intermediates multistep phosphorelay (MSP) plant hormone signaling structural basis of AHP1-ARR4 interaction two-component signaling (TCS) AHP1 protein, Arabidopsis mehr... |
| Zusammenfassung: | © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust. Eukaryotic two-component signaling involves the His-Asp-His-Asp multistep phosphorelay (MSP). In Arabidopsis thaliana, cytokinin-mediated MSP signaling intermediates include histidine kinases (HKs), histidine phosphotransfer proteins (Hpts) and response regulators (RRs). The structure-function relationship of interaction between Hpt (e.g. AHP1) and RR (e.g. ARR4) is poorly understood. Using a homology model and yeast two-hybrid analysis, we identified key amino acids of ARR4 at the AHP1-ΔARR4((16-175)) interaction interface. Mutating them in Arabidopsis (arr3,4,5,6,8,9 hextuple mutant background) and performing root length assays provided functional relevance, and coimmunoprecipitation (coIP) assay provided biochemical evidence for the interaction. The homology model mimics crystal structures of Hpt-RR complexes. Mutating selected interface residues of ARR4 either abolished or destabilized the interaction. D45A and Y96A mutations weakened interaction with AHP1, and exhibited weaker rescue of root elongation in the hextuple mutants. CoIP analysis using cytokinin-treated transgenic Arabidopsis seedlings provided biochemical evidence for weakened AHP1-ARR4 interaction. The relevance of the selected residues for the interaction was further validated in two independent pairs of Hpt-RR proteins from Arabidopsis and rice (Oryza sativa). Our data provide evidence of a link between Hpt-RR interaction affinity and regulation of downstream functions of RRs. This establishes a structure-function relationship for the final step of a eukaryotic MSP signal cascade |
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| Beschreibung: | Date Completed 04.01.2016 Date Revised 29.01.2022 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1469-8137 |
| DOI: | 10.1111/nph.13297 |