title: Structural Aspects of Multistep Phosphorelay-Mediated Signaling in Plants.
abstract: The multistep phosphorelay (MSP) is a central signaling pathway in plants integrating a wide spectrum of hormonal and environmental inputs and controlling numerous developmental adaptations. For the thorough comprehension of the molecular mechanisms underlying the MSP-mediated signal recognition and transduction, the detailed structural characterization of individual members of the pathway is critical. In this review we describe and discuss the recently known crystal and nuclear magnetic resonance structures of proteins acting in MSP signaling in higher plants, focusing particularly on cytokinin and ethylene signaling in Arabidopsis thaliana. We discuss the range of functional aspects of available structural information including determination of ligand specificity, activation of the receptor via its autophosphorylation, and downstream signal transduction through the phosphorelay. We compare the plant structures with their bacterial counterparts and show that although the overall similarity is high, the differences in structural details are frequent and functionally important. Finally, we discuss emerging knowledge on molecular recognition mechanisms in the MSP, and mention the latest findings regarding structural determinants of signaling specificity in the Arabidopsis MSP that could serve as a general model of this pathway in all higher plants.
authors.affiliation: Central European Institute of Technology (CEITEC), Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic.
authors.forename: Blanka
authors.initials: B
authors.lastname: Pekárová
authors.affiliation: Central European Institute of Technology (CEITEC), Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Szmitkowska
authors.affiliation: Central European Institute of Technology (CEITEC), Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic.
authors.forename: Radka
authors.initials: R
authors.lastname: Dopitová
authors.affiliation: Faculty of Science, Institute of Chemistry and Biochemistry, University of South Bohemia, 370 05 České Budějovice, Czech Republic.
authors.forename: Oksana
authors.initials: O
authors.lastname: Degtjarik
authors.affiliation: Central European Institute of Technology (CEITEC), Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic.
authors.forename: Lukáš
authors.initials: L
authors.lastname: Žídek
authors.affiliation: Central European Institute of Technology (CEITEC), Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic. Electronic address: hejatko@sci.muni.cz.
authors.forename: Jan
authors.initials: J
authors.lastname: Hejátko
mesh_terms: D017360:Arabidopsis; D003583:Cytokinins / Q000378:metabolism; D005030:Ethylenes / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry* / Q000378:metabolism*; D015398:Signal Transduction; D013329:Structure-Activity Relationship
chemical_list: D003583:Cytokinins; D005030:Ethylenes; D010940:Plant Proteins; C036216:ethylene
keywords: histidine kinase; multistep phosphorelay; phosphotransfer protein; response regulator; structure