brassinosteroid
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Brassinosteroids are steroidal phytohormones that regulate plant development and physiology, including adaptation to environmental stresses. Brassinosteroids are synthesized in the cell interior but bind receptors at the cell surface, necessitating a yet to be identified export mechanism. Here, we show that a member of the ATP-binding cassette (ABC) transporter superfamily, ABCB19, functions as a brassinosteroid exporter. We present its structure in both the substrate-unbound and the brassinosteroid-bound states. Bioactive brassinosteroids are potent activators of ABCB19 ATP hydrolysis activity, and transport assays showed that ABCB19 transports brassinosteroids. In Arabidopsis thaliana, ABCB19 and its close homolog, ABCB1, positively regulate brassinosteroid responses. Our results uncover an elusive export mechanism for bioactive brassinosteroids that is tightly coordinated with brassinosteroid signaling.
- MeSH
- ABC transportéry * chemie genetika metabolismus MeSH
- adenosintrifosfát metabolismus MeSH
- Arabidopsis * genetika metabolismus MeSH
- brassinosteroidy * metabolismus MeSH
- konformace proteinů MeSH
- kyseliny indoloctové metabolismus MeSH
- proteiny huseníčku * chemie genetika metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
Three BS-BODIPY (brassinosteroids-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene) conjugates were synthesized and their fluorescent and immunological properties were investigated. Two of the conjugates, having present all the functional groups characteristic of BS, were shown to be potentially useful as biological probes to study involvement of BS into physiological processes in living cells.
- MeSH
- brassinosteroidy chemie MeSH
- sloučeniny boru chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Thirteen monohydroxylated brassinosteroids analogues were synthesized and tested for their biological activity in plant and animal systems. The cytotoxic activity of the products was studied using human normal and cancer cell lines with 28-homocastasterone as positive control, their brassinolide type activity was established using the bean second-internode test with 24-epibrassinolide as standard.
- MeSH
- brassinosteroidy aplikace a dávkování chemická syntéza MeSH
- cholestanoly aplikace a dávkování chemická syntéza MeSH
- cytotoxiny aplikace a dávkování chemická syntéza MeSH
- lidé MeSH
- molekulární struktura MeSH
- nádorové buněčné linie MeSH
- proliferace buněk účinky léků MeSH
- steroidy heterocyklické aplikace a dávkování MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
We have prepared and studied a series of new brassinosteroid derivatives with a p-substituted phenyl group in the side chain. To obtain the best comparison between molecular docking and biological activities both types of brassinosteroids were synthesized; 6-ketones, 10 examples, and B-lactones, 8 examples. The phenyl group was introduced into the steroid skeleton by Horner-Wadsworth-Emmons. The docking studies were carried out using AutoDock Vina 1.05. Plant biological activities were established using different brassinosteroid bioassays in comparison with natural brassinosteroids. Differences in the production of the plant hormone ethylene were also observed in etiolated pea seedlings after treatment with new brassinosteroids. The most active compounds were lactone 8f and 6-oxo derivatives 8c and 9c, their biological activities were comparable or even better than naturally occurring brassinolide. Finally the cytotoxicity of the new derivatives was studied using human normal and cancer cell lines.
- MeSH
- Arabidopsis metabolismus MeSH
- brassinosteroidy chemie metabolismus farmakologie MeSH
- lidé MeSH
- nádorové buněčné linie MeSH
- nádory farmakoterapie MeSH
- proteinkinasy metabolismus MeSH
- proteiny huseníčku metabolismus MeSH
- protinádorové látky chemie metabolismus farmakologie MeSH
- regulátory růstu rostlin metabolismus MeSH
- simulace molekulového dockingu MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Using Arabidopsis thaliana wild type (WT) plants and diacylglycerol kinase knockouts (single mutants - dgk3, dgk1, dgk6; double mutants - dgk3dgk7, dgk5dgk6, dgk1dgk2) we observed that the inhibitor of brassinosteroid (BR) biosynthesis, brassinazole (BRZ), drastically decreased germination of dgk mutants under salt stress, while BRZ co-administration with 24-epibrassinolide (EBL) partially improved germination rates. We also observed a statistically significant decrease in alternative and cytochrome respiratory pathways in response to BRZ treatment under salinity conditions. We showed that production of the lipid second messenger phosphatidic acid (PA) is impaired in dgk mutants in response to EBL treatment and inhibitor of diacylglycerol kinase (DGK) - R59022. This study demonstrates that dgk mutants possess lower germination rates, lower total respiration rates, an alternative respiratory pathway and PA content under optimal and high salinity conditions in response to EBL treatment comparing to WT plants.
- MeSH
- Arabidopsis chemie metabolismus MeSH
- brassinosteroidy farmakologie MeSH
- diacylglycerolkinasa antagonisté a inhibitory nedostatek metabolismus MeSH
- kyseliny fosfatidové chemie metabolismus MeSH
- salinita MeSH
- semena rostlinná účinky léků růst a vývoj metabolismus MeSH
- triazoly farmakologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Reduced plant height and culm robustness are quantitative characteristics important for assuring cereal crop yield and quality under adverse weather conditions. A very limited number of short-culm mutant alleles were introduced into commercial crop cultivars during the Green Revolution. We identified phenotypic traits, including sturdy culm, specific for deficiencies in brassinosteroid biosynthesis and signaling in semidwarf mutants of barley (Hordeum vulgare). This set of characteristic traits was explored to perform a phenotypic screen of near-isogenic short-culm mutant lines from the brachytic, breviaristatum, dense spike, erectoides, semibrachytic, semidwarf, and slender dwarf mutant groups. In silico mapping of brassinosteroid-related genes in the barley genome in combination with sequencing of barley mutant lines assigned more than 20 historic mutants to three brassinosteroid-biosynthesis genes (BRASSINOSTEROID-6-OXIDASE, CONSTITUTIVE PHOTOMORPHOGENIC DWARF, and DIMINUTO) and one brassinosteroid-signaling gene (BRASSINOSTEROID-INSENSITIVE1 [HvBRI1]). Analyses of F2 and M2 populations, allelic crosses, and modeling of nonsynonymous amino acid exchanges in protein crystal structures gave a further understanding of the control of barley plant architecture and sturdiness by brassinosteroid-related genes. Alternatives to the widely used but highly temperature-sensitive uzu1.a allele of HvBRI1 represent potential genetic building blocks for breeding strategies with sturdy and climate-tolerant barley cultivars.
- MeSH
- alely MeSH
- aminokyseliny MeSH
- brassinosteroidy metabolismus MeSH
- fenotyp MeSH
- ječmen (rod) genetika růst a vývoj metabolismus MeSH
- jedlá semena MeSH
- mapování chromozomů MeSH
- modely strukturální MeSH
- molekulární sekvence - údaje MeSH
- mutace MeSH
- počasí MeSH
- počítačová simulace MeSH
- regulace genové exprese u rostlin * MeSH
- sekvence nukleotidů MeSH
- sekvenční analýza DNA MeSH
- signální transdukce MeSH
- teplota MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
Brassinosteroids are a class of plant hormones that regulate a broad range of physiological processes such as plant growth, development and immunity, including the suppression of biotic and abiotic stresses. In this paper, we report the synthesis of new brassinosteroid analogues with a nitrogen-containing side chain and their biological activity on Arabidopis thaliana. Based on molecular docking experiments, two groups of brassinosteroid analogues were prepared with short and long side chains in order to study the impact of side chain length on plants. The derivatives with a short side chain were prepared with amide, amine and ammonium functional groups. The derivatives with a long side chain were synthesized using amide and ammonium functional groups. A total of 25 new brassinosteroid analogues were prepared. All 25 compounds were tested in an Arabidopsis root sensitivity bioassay and cytotoxicity screening. The synthesized substances showed no significant inhibitory activity compared to natural 24-epibrassinolide. In contrast, in low concentration, several compounds (8a, 8b, 8e, 16e, 22a and 22e) showed interesting growth-promoting activity. The cytotoxicity assay showed no toxicity of the prepared compounds on cancer and normal cell lines.
Brassinosteroids (BRs) are a group of polyhydroxylated sterol derivatives with important regulatory roles in various plant physiological processes. The aim of this study was to examine the mechanism of the antiproliferative activity of natural BRs 28-homocastasterone (28-homoCS) and 24-epibrassinolide (24-epiBL) in hormone-sensitive and -insensitive (LNCaP and DU-145, respectively) human prostate cancer cell lines. The effects of BRs on prostate cancer cells were surveyed using flow cytometry, Western blotting, TUNEL, DNA ladder assays and immunofluorescence analyses. The studied BRs inhibited cell growth and induced G(1) blocks in LNCaP cells accompanied by reductions in cyclin D(1), CDK4/6 and pRb expression. Following BR treatment of DU-145 cells, increases in proportions of cells in the G(2)/M phase of cell cycle were observed, accompanied by down-regulation of cyclins A and B(1). Changes in AR localization patterns in LNCaP cells treated with BRs were shown by immunofluorescence analysis. Furthermore, apoptotic detection methods demonstrated induction of apoptosis mediated by BRs in both cell lines, although changes in the expression of apoptosis-related proteins were modulated differently by 28-homoCS and 24-piBL in each cell line. The studied BRs seem to exert potent growth inhibitory and pro-apoptotic effects and could be therefore highly valuable new candidates for prostate anticancer drugs.
- MeSH
- androgenní receptory metabolismus MeSH
- apoptóza účinky léků MeSH
- brassinosteroidy farmakologie MeSH
- buněčný cyklus účinky léků MeSH
- cholestanony farmakologie MeSH
- cyklin D1 metabolismus MeSH
- cyklin-dependentní kinasa 4 metabolismus MeSH
- cyklin-dependentní kinasa 6 metabolismus MeSH
- fytogenní protinádorové látky farmakologie MeSH
- lidé MeSH
- nádorové buněčné linie MeSH
- nádory prostaty farmakoterapie metabolismus patologie MeSH
- receptory pro estrogeny metabolismus MeSH
- screeningové testy protinádorových léčiv MeSH
- steroidy heterocyklické farmakologie MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Brassinosteroids (BRs) are plant-specific steroid hormones that play essential roles in the regulation of many important physiological processes in plant life. Their extremely low concentrations (~pmoles/g FW) in plant tissue and huge differences in polarity of individual members within the BR family hamper their detection and quantification. To address this problem, an immunoaffinity sorbent with broad specificity and high capacity for different BR metabolites containing a monoclonal antibody (mAb) against a BR spacer (20S)-2α,3α-dihydroxy-7-oxa-7α-homo-5α-pregnane-6-one-20 carboxylic acid (BR4812) was used for the rapid and highly selective isolation of endogenous BRs containing a 2α,3α-diol in ring A from minute plant samples. This enrichment procedure was successfully applied as a sample preparation method prior to quantitative analysis of BRs in real plant tissues by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Use of immunoaffinity chromatography (IAC) increased the sensitivity of the UHPLC-MS/MS analysis owing to improvements in the BR signal-to-noise ratio (S/N) and matrix factor (MF). Although MF values of BRs analyzed in classical samples ranged from 8.9% to 47.4%, MF values for the IAC purified samples reached 44.5-96.6%. Thus, the developed IAC-UHPLC-MS/MS approach was shown to be a simple, robust, effective and extremely fast procedure requiring minute amounts of plant samples suitable for the quantitative profiling of many BR metabolites, helping to overcome the major problems associated with their determination in very complex plant matrices.
- MeSH
- Brassica napus chemie MeSH
- brassinosteroidy analýza izolace a purifikace MeSH
- chromatografie afinitní metody MeSH
- imobilizační protilátky chemie MeSH
- imunosorbenty chemie MeSH
- regulátory růstu rostlin analýza izolace a purifikace MeSH
- rostlinné extrakty chemie MeSH
- tandemová hmotnostní spektrometrie metody MeSH
- vysokoúčinná kapalinová chromatografie metody MeSH
- Publikační typ
- časopisecké články MeSH
Late stage CH functionalization is a powerful tool for modification of natural compounds. Herein we report that the rhodium-catalyzed reaction of brassinosteroids with aryloxysulfonamides proceeds regio- and stereoselectively at C15 position. The derivative obtained from 24-epibrassinolide was easily transformed to the conjugate with a BODIPY dye bearing unaffected functional groups of the native brassinosteroid.
