Identification of CRE1 as a cytokinin receptor from Arabidopsis.
Cytokinins are a class of plant hormones that are central to the regulation of cell division and differentiation in plants. It has been proposed that they are detected by a two-component system, because overexpression of the histidine kinase gene CKI1 induces typical cytokinin responses and genes for a set of response regulators of two-component systems can be induced by cytokinins. Two-component systems use a histidine kinase as an environmental sensor and rely on a phosphorelay for signal transduction. They are common in microorganisms, and are also emerging as important signal detection routes in plants. Here we report the identification of a cytokinin receptor. We identified Arabidopsis cre1 (cytokinin response 1) mutants, which exhibited reduced responses to cytokinins. The mutated gene CRE1 encodes a histidine kinase. CRE1 expression conferred a cytokinin-dependent growth phenotype on a yeast mutant that lacked the endogenous histidine kinase SLN1 (ref. 10), providing direct evidence that CRE1 is a cytokinin receptor. We also provide evidence that cytokinins can activate CRE1 to initiate phosphorelay signalling.
Department of Biology, Graduate School of Science, Osaka University, Toyonaka, Japan.
T
T
Inoue
M
M
Higuchi
Y
Y
Hashimoto
M
M
Seki
M
M
Kobayashi
T
T
Kato
S
S
Tabata
K
K
Shinozaki
T
T
Kakimoto
D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins; D002874:Chromosome Mapping; D003583:Cytokinins / Q000378:metabolism*; D004269:DNA, Bacterial; D017343:Genes, Plant; D000071677:Histidine Kinase; D008969:Molecular Sequence Data; D009154:Mutation; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D014170:Transformation, Genetic; D015003:Yeasts / Q000235:genetics
D029681:Arabidopsis Proteins; D003583:Cytokinins; D004269:DNA, Bacterial; D010940:Plant Proteins; D011956:Receptors, Cell Surface; C036483:T-DNA; D011494:Protein Kinases; D000071677:Histidine Kinase; C421783:WOL protein, Arabidopsis