The Arabidopsis AHK4 Histidine Kinase is a Cytokinin-Binding Receptor that Transduces Cytokinin Signals Across the Membrane
Asp) phosphorelay is a paradigm of signal transduction in both prokaryotes and eukaryotes for the propagation of certain environmental stimuli, in which histidine (His)-kinases play central roles as sensors for environmental signals. For the higher plant, Arabidopsis thaliana, it was recently suggested that the His-kinase (AHK4 / CRE1 / WOL) is a sensor for cytokinins, which are a class of plant hormones important for the regulation of cell division and differentiation. Interestingly, AHK4 is capable of functioning as a cytokinin sensor in the eubacterium, Escherichia coli (Suzuki et al. 2001, Plant Cell Physiol. 42: 107). Here we further show that AHK4 is a primary receptor that directly binds a variety of natural and synthetic cytokinins (e.g. not only N(6)-substituted aminopurines such as isopentenyl-adenine, trans-zeatin, benzyl-adenine, but also diphenylurea derivatives such as thidiazuron), in a highly specific manner (K(d) = 4.55+/-0.48x10(-9) M). AHK4 has a presumed extracellular domain, within which a single amino acid substitution (Thr-301 to Ile) was shown to result in loss of its ability to bind cytokinins. This particular mutation corresponds to the previously reported wol allele (wooden leg) that causes a striking phenotype defective in vascular morphogenesis. Collectively, evidence is presented that AHK4 and its homologues (AHK3 and possibly AHK2) are receptor kinases that can transduce cytokinin signals across the plasma membrane of A. thaliana. -->ISSN: | 1471-9053 0032-0781 |
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DOI: | 10.1093/pcp/pce127 |
Přístupová URL adresa: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::15d4c6ece09d807fd75aea7173c2ba43 https://doi.org/10.1093/pcp/pce127 |
Rights: | OPEN |
Přírůstkové číslo: | edsair.doi.dedup.....15d4c6ece09d807fd75aea7173c2ba43 |
Autor: | Kentaro Takei, Kuniko Ishikawa, Kazunori Terada, Takeshi Mizuno, Takafumi Yamashino, Kumiko Miwa, Hisami Yamada, Tomomi Suzuki |
Rok vydání: | 2001 |
Předmět: |
Cytokinins
Histidine Kinase Cell division Zeatin Physiology Molecular Sequence Data Arabidopsis Plant Science Isopentenyladenosine chemistry.chemical_compound Cytokinin binding Arabidopsis thaliana Tissue Distribution Amino Acid Sequence Receptor Sequence Homology Amino Acid biology Arabidopsis Proteins Chemistry Adenine Cell Membrane fungi Histidine kinase food and beverages Cell Differentiation Cell Biology General Medicine beta-Galactosidase biology.organism_classification Biochemistry Cytokinin Signal transduction Protein Kinases Cell Division Signal Transduction |
Zdroj: | Plant and Cell Physiology. 42:1017-1023 |
ISSN: | 1471-9053 0032-0781 |
DOI: | 10.1093/pcp/pce127 |
Popis: | Common histidine-to-aspartate (His-->Asp) phosphorelay is a paradigm of signal transduction in both prokaryotes and eukaryotes for the propagation of certain environmental stimuli, in which histidine (His)-kinases play central roles as sensors for environmental signals. For the higher plant, Arabidopsis thaliana, it was recently suggested that the His-kinase (AHK4 / CRE1 / WOL) is a sensor for cytokinins, which are a class of plant hormones important for the regulation of cell division and differentiation. Interestingly, AHK4 is capable of functioning as a cytokinin sensor in the eubacterium, Escherichia coli (Suzuki et al. 2001, Plant Cell Physiol. 42: 107). Here we further show that AHK4 is a primary receptor that directly binds a variety of natural and synthetic cytokinins (e.g. not only N(6)-substituted aminopurines such as isopentenyl-adenine, trans-zeatin, benzyl-adenine, but also diphenylurea derivatives such as thidiazuron), in a highly specific manner (K(d) = 4.55+/-0.48x10(-9) M). AHK4 has a presumed extracellular domain, within which a single amino acid substitution (Thr-301 to Ile) was shown to result in loss of its ability to bind cytokinins. This particular mutation corresponds to the previously reported wol allele (wooden leg) that causes a striking phenotype defective in vascular morphogenesis. Collectively, evidence is presented that AHK4 and its homologues (AHK3 and possibly AHK2) are receptor kinases that can transduce cytokinin signals across the plasma membrane of A. thaliana. |
Databáze: | OpenAIRE |
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