Cytokinin activity of N<sup>6</sup>-benzyladenine derivatives assayed by interaction with the receptors in planta, in vitro, and in silico
|
01.05.2018 |
Savelieva E.
Oslovsky V.
Karlov D.
Kurochkin N.
Getman I.
Lomin S.
Sidorov G.
Mikhailov S.
Osolodkin D.
Romanov G.
|
Phytochemistry |
|
3 |
Ссылка
© 2018 Elsevier Ltd Biological effects of hormones in both plants and animals are based on high-affinity interaction with cognate receptors resulting in their activation. The signal of cytokinins, classical plant hormones, is perceived in Arabidopsis by three homologous membrane receptors: AHK2, AHK3, and CRE1/AHK4. To study the cytokinin–receptor interaction, we used 25 derivatives of potent cytokinin N6-benzyladenine (BA) with substituents in the purine heterocycle and/or in the side chain. The study was focused primarily on individual cytokinin receptors from Arabidopsis. The main in planta assay system was based on Arabidopsis double mutants retaining only one isoform of cytokinin receptors and harboring cytokinin-sensitive reporter gene. Classical cytokinin biotest with Amaranthus seedlings was used as an additional biotest. In parallel, the binding of ligands to individual cytokinin receptors was assessed in the in vitro test system. Quantitative comparison of results of different assays confirmed the partial similarity of ligand-binding properties of receptor isoforms. Substituents at positions 8 and 9 of adenine moiety, elongated linker up to 4 methylene units, and replacement of N6 by sulfur or oxygen have resulted in the suppression of cytokinin activity of the derivative toward all receptors. Introduction of a halogen into position 2 of adenine moiety, on the contrary, often increased the ligand activity, especially toward AHK3. Features both common and distinctive of cytokinin receptors in Arabidopsis and Amaranthus were revealed, highlighting species specificity of the cytokinin perception apparatus. Correlations between the extent to which a compound binds to a receptor in vitro and its ability to activate the same receptor in planta were evaluated for each AHK protein. Interaction patterns between individual receptors and ligands were rationalized by structure analysis and molecular docking in sensory modules of AHK receptors. The best correlation between docking scores and specific binding was observed for AHK3. In addition, receptor-specific ligands have been discovered with unique properties to predominantly activate or block distinct cytokinin receptors. These ligands are promising for practical application and as molecular tools in the study of the cytokinin perception by plant cells.
Читать
тезис
|
Genotype-phenotype correlations of the course of cystic fibrosis in Russian children. the first description of eleven new mutations
|
01.01.2018 |
Gorinova Y.
Savostyanov K.
Pushkov A.
Nikitin A.
Pen'Kov E.
Krasovskiy S.
Simonova O.
Namazova-Baranova L.
|
Voprosy Sovremennoi Pediatrii - Current Pediatrics |
|
0 |
Ссылка
© 2018 Publishing House of the Union of Pediatricians. All rights reserved. Background. Cystic fibrosis is a hereditary disease that occurs as a result of mutations in the regulator gene of chloride ion transmembrane transport (CFTR). Finding mutations in the CFTR gene is necessary for identification of the clinical features of cystic fibrosis. Objective. Our aim was to identify genotype-phenotype correlations between mutations of the first class of pathogenicity and clinical manifestations of cystic fibrosis based on studying the prevalence and structure of CFTR gene mutations. Methods. The study included children under 18 years with cystic fibrosis admitted to hospital between 2013 and 2017. Biallelic mutations in the CFTR gene were the non-inclusion criterion. The CFTR gene variants were analyzed by next-generation sequencing method. Results. In 125 patients with cystic fibrosis, 59 different variants of the CFTR gene were detected, 11 of them not previously described. The most common was the deletion c.1521-1523del found in 98 (39.2%) of the 250 analyzed CFTR gene alleles and the deletion c.1545-1546del found in 22/250 (8.8%) alleles. It has been shown that the mutation c.1545-1546del, p.Y515∗ was more often found in children of the Chechen nation-odds ratio (OR) 139 (95% confidence interval 15-1,257). It has been established that meconium ileus, pancreatic deficiency and cirrhosis are more common in patients with mutations of the first category of pathogenicity: OR 3.9 (95% CI 1.0-15.0), 4.4 (95% CI 1.8-11.1), and 351 (95% CI 17.5-7,046), respectively. The association of CFTR gene mutations with the development of bronchiectases and polypous pancinusitis has not been found. Conclusion. Correlations between the genotype and clinical manifestations of cystic fibrosis in Russian children with CFTR gene mutations of the first class of pathogenicity have been established.
Читать
тезис
|
Cytokinin activity of N6-benzyladenine derivatives assayed by interaction with the receptors in planta, in vitro, and in silico
|
|
Осолодкин Дмитрий Иванович
|
Phytochemistry |
|
|
Biological effects of hormones in both plants and animals are based on high-affinity interaction with cognate receptors resulting in their activation. The signal of cytokinins, classical plant hormones, is perceived in Arabidopsis by three homologous membrane receptors: AHK2, AHK3, and CRE1/AHK4. To study the cytokinin-receptor interaction, we used 25 derivatives of potent cytokinin N6-benzyladenine (BA) with substituents in the purine heterocycle and/or in the side chain. The study was focused primarily on individual cytokinin receptors from Arabidopsis. The main in planta assay system was based on Arabidopsis double mutants retaining only one isoform of cytokinin receptors and harboring cytokinin-sensitive reporter gene. Classical cytokinin biotest with Amaranthus seedlings was used as an additional biotest. In parallel, the binding of ligands to individual cytokinin receptors was assessed in the in vitro test system. Quantitative comparison of results of different assays confirmed the partial similarity of ligand-binding properties of receptor isoforms. Substituents at positions 8 and 9 of adenine moiety, elongated linker up to 4 methylene units, and replacement of N6 by sulfur or oxygen have resulted in the suppression of cytokinin activity of the derivative toward all receptors. Introduction of a halogen into position 2 of adenine moiety, on the contrary, often increased the ligand activity, especially toward AHK3. Features both common and distinctive of cytokinin receptors in Arabidopsis and Amaranthus were revealed, highlighting species specificity of the cytokinin perception apparatus. Correlations between the extent to which a compound binds to a receptor in vitro and its ability to activate the same receptor in planta were evaluated for each AHK protein. Interaction patterns between individual receptors and ligands were rationalized by structure analysis and molecular docking in sensory modules of AHK receptors. The best correlation between docking scores and specific binding was observed for AHK3. In addition, receptor-specific ligands have been discovered with unique properties to predominantly activate or block distinct cytokinin receptors. These ligands are promising for practical application and as molecular tools in the study of the cytokinin perception by plant cells.
Читать
тезис
Публикация |
Cytokinin activity of N6-benzyladenine derivatives assayed by interaction with the receptors in planta, in vitro, and in silico
|
|
Осолодкин Дмитрий Иванович (Доцент)
|
Phytochemistry |
|
|
Biological effects of hormones in both plants and animals are based on high-affinity interaction with cognate receptors resulting in their activation. The signal of cytokinins, classical plant hormones, is perceived in Arabidopsis by three homologous membrane receptors: AHK2, AHK3, and CRE1/AHK4. To study the cytokinin-receptor interaction, we used 25 derivatives of potent cytokinin N6-benzyladenine (BA) with substituents in the purine heterocycle and/or in the side chain. The study was focused primarily on individual cytokinin receptors from Arabidopsis. The main in planta assay system was based on Arabidopsis double mutants retaining only one isoform of cytokinin receptors and harboring cytokinin-sensitive reporter gene. Classical cytokinin biotest with Amaranthus seedlings was used as an additional biotest. In parallel, the binding of ligands to individual cytokinin receptors was assessed in the in vitro test system. Quantitative comparison of results of different assays confirmed the partial similarity of ligand-binding properties of receptor isoforms. Substituents at positions 8 and 9 of adenine moiety, elongated linker up to 4 methylene units, and replacement of N6 by sulfur or oxygen have resulted in the suppression of cytokinin activity of the derivative toward all receptors. Introduction of a halogen into position 2 of adenine moiety, on the contrary, often increased the ligand activity, especially toward AHK3. Features both common and distinctive of cytokinin receptors in Arabidopsis and Amaranthus were revealed, highlighting species specificity of the cytokinin perception apparatus. Correlations between the extent to which a compound binds to a receptor in vitro and its ability to activate the same receptor in planta were evaluated for each AHK protein. Interaction patterns between individual receptors and ligands were rationalized by structure analysis and molecular docking in sensory modules of AHK receptors. The best correlation between docking scores and specific binding was observed for AHK3. In addition, receptor-specific ligands have been discovered with unique properties to predominantly activate or block distinct cytokinin receptors. These ligands are promising for practical application and as molecular tools in the study of the cytokinin perception by plant cells.
Читать
тезис
Публикация |