Streptococcus pneumoniae is an opportunistic human pathogen that encodes a single eukaryotic-type Ser/Thr protein kinase StkP and its functional counterpart, the protein phosphatase PhpP. These signaling enzymes play critical roles in coordinating cell division and growth in pneumococci. In this study, we determined the proteome and phosphoproteome profiles of relevant mutants. Comparison of those with the wild-type provided a representative dataset of novel phosphoacceptor sites and StkP-dependent substrates. StkP phosphorylates key proteins involved in cell division and cell wall biosynthesis in both the unencapsulated laboratory strain Rx1 and the encapsulated virulent strain D39. Furthermore, we show that StkP plays an important role in triggering an adaptive response induced by a cell wall-directed antibiotic. Phosphorylation of the sensor histidine kinase WalK and downregulation of proteins of the WalRK core regulon suggest crosstalk between StkP and the WalRK two-component system. Analysis of proteomic profiles led to the identification of gene clusters regulated by catabolite control mechanisms, indicating a tight coupling of carbon metabolism and cell wall homeostasis. The imbalance of steady-state protein phosphorylation in the mutants as well as after antibiotic treatment is accompanied by an accumulation of the global Spx regulator, indicating a Spx-mediated envelope stress response. In summary, StkP relays the perceived signal of cell wall status to key cell division and regulatory proteins, controlling the cell cycle and cell wall homeostasis.
- MeSH
- antibakteriální látky farmakologie MeSH
- bakteriální proteiny metabolismus MeSH
- buněčná stěna účinky léků fyziologie MeSH
- fosfoproteiny metabolismus MeSH
- fosforylace MeSH
- fyziologický stres * MeSH
- proteinkinasy metabolismus MeSH
- proteom MeSH
- Streptococcus pneumoniae účinky léků fyziologie MeSH
- Publikační typ
- časopisecké články MeSH
- dataset MeSH
- práce podpořená grantem MeSH
α-Terpineol, terpinen-4-ol, and δ-terpineol, isomers of terpineol, are among the compounds that give Cinnamomum longepaniculatum leaf oil its distinguished pleasant smell. The objective of this study was to evaluate the antimicrobial activity of these three isomeric terpineols. The determination of antibacterial activity was based on the minimum inhibition concentration (MIC) and minimum bactericide concentration (MBC). Changes in time-kill curve, alkaline phosphatase (AKP), UV-absorbing material, membrane potential, and scanning electron microscopy (SEM) were measured to elucidate the possible antimicrobial mechanism. α-Terpineol, terpinen-4-ol, and δ-terpineol demonstrated good inhibitory effects against several gram-negative bacteria, particularly Shigella flexneri. MIC and MBC of α-terpineol and terpinen-4-ol were similar (0.766 mg/mL and 1.531 mg/mL, respectively) for S. flexneri, while the MIC and MBC values of δ-terpineol were 0.780 mg/mL and 3.125 mg/mL, respectively. Time-kill curves showed that the antibacterial activities of the tested compounds were in a concentration-dependent manner. Release of nucleic acids and proteins along with a decrease in membrane potential proved that α-terpineol, terpinen-4-ol, and δ-terpineol could increase the membrane permeability of Shigella flexneri. Additionally, the release of AKP suggested that the cell wall was destroyed. SEM analysis further confirmed that S. flexneri cell membranes were damaged by α-terpineol, terpinen-4-ol, and δ-terpineol. Our research suggests that these three isomeric terpineols have the potential of being used as natural antibacterial agents by destroying the cell membrane and wall, resulting in cell death. However, the specific antibacterial activity differences need further investigation.
- MeSH
- antibakteriální látky chemie farmakologie MeSH
- buněčná stěna účinky léků MeSH
- gramnegativní bakterie účinky léků MeSH
- isomerie MeSH
- listy rostlin chemie MeSH
- membránové potenciály účinky léků MeSH
- mikrobiální testy citlivosti MeSH
- oleje prchavé chemie farmakologie MeSH
- skořicovník chemie MeSH
- terpeny chemie farmakologie MeSH
- Publikační typ
- časopisecké články MeSH
The most recent genome-editing system called CRISPR-Cas9 (clustered regularly interspaced short palindromic repeat system with associated protein 9-nuclease) was employed to delete four non-essential genes (i.e., Caeco1, Caidh1, Carom2, and Cataf10) individually to establish their gene functionality annotations in pathogen Candida albicans. The biological roles of these genes were investigated with respect to the cell wall integrity and biogenesis, calcium/calcineurin pathways, susceptibility of mutants towards temperature, drugs and salts. All the mutants showed increased vulnerability compared to the wild-type background strain towards the cell wall-perturbing agents, (antifungal) drugs and salts. All the mutants also exhibited repressed and defective hyphal growth and smaller colony size than control CA14. The cell cycle of all the mutants decreased enormously except for those with Carom2 deletion. The budding index and budding size also increased for all mutants with altered bud shape. The disposition of the mutants towards cell wall-perturbing enzymes disclosed lower survival and more rapid cell wall lysis events than in wild types. The pathogenicity and virulence of the mutants was checked by adhesion assay, and strains lacking rom2 and eco1 were found to possess the least adhesion capacity, which is synonymous to their decreased pathogenicity and virulence.
- MeSH
- acetyltransferasy nedostatek genetika fyziologie MeSH
- antifungální látky farmakologie MeSH
- buněčná adheze MeSH
- buněčná stěna účinky léků MeSH
- buněčný cyklus MeSH
- Candida albicans účinky léků genetika patogenita fyziologie MeSH
- chitinasy farmakologie MeSH
- CRISPR-Cas systémy MeSH
- delece genu MeSH
- endo-1,3-beta-glukanasa farmakologie MeSH
- faktory asociované s proteinem vázajícím TATA box nedostatek genetika fyziologie MeSH
- fungální proteiny genetika fyziologie MeSH
- geny hub * MeSH
- hyfy růst a vývoj MeSH
- isocitrátdehydrogenasa nedostatek genetika fyziologie MeSH
- kationty farmakologie MeSH
- nepohlavní rozmnožování MeSH
- otevřené čtecí rámce MeSH
- poškození DNA MeSH
- vápník fyziologie MeSH
- virulence genetika MeSH
- Publikační typ
- časopisecké články MeSH
Tall fescue (Festuca arundinacea Schreb) shows remarkable tolerance to lead (Pb), but the mechanisms involved in metal tolerance are not yet well understood. Here, tall fescue were firstly cultivated hydroponically with Pb2+ (0, 50, 200 and 1000 mg/L) for 14 days. The results showed that remodeling of root architecture plays important roles in tolerance of tall fescue to Pb2+ stress. Increased cell wall (CW) components contribute to restrict high amount of Pb2+ in roots. Additionally, the uronic acid contents of pectin, hemicellulose 1 (HC1) and hemicellulose 2 (HC2) increased under Pb2+ stress. We further observed that tall fescue cultivated with H2O2 showed similar remodeling of root architecture as Pb2+ treatment. Furthermore, pectin, HC1 and HC2 fractions were sequentially extracted from 0 and 10 mM H2O2 treated roots, and Pb2+ adsorption capacity and contents of carboxyl groups of pectin and HC2 fractions were steadily increased under H2O2 treatment in vitro. Our results suggest that degrees of esterification of pectin and HC2 are regulated by H2O2. High amount of low-esterified pectin and HC2 offer more carboxyl groups, provide more Pb2+ binding sites, and restrict more Pb2+ in the CW, which may enhance tolerance of tall fescue to Pb2+ stress.
- MeSH
- buněčná stěna účinky léků metabolismus MeSH
- esterifikace MeSH
- Festuca účinky léků metabolismus MeSH
- kořeny rostlin účinky léků metabolismus MeSH
- látky znečišťující půdu metabolismus toxicita MeSH
- olovo metabolismus toxicita MeSH
- oxidační stres účinky léků MeSH
- polysacharidy chemie metabolismus MeSH
- reaktivní formy kyslíku metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
This study explored the antitubercular properties of fucoxanthin, a marine carotenoid, against clinical isolates of Mycobacterium tuberculosis (Mtb). Two vital enzymes involved in Mtb cell wall biosynthesis, UDP-galactopyranose mutase (UGM) and arylamine-N-acetyltransferase (TBNAT), were selected as drug targets to reveal the mechanism underlying the antitubercular effect of fucoxanthin. The obtained results showed that fucoxanthin showed a clear bacteriostatic action against the all Mtb strains tested, with minimum inhibitory concentrations (MIC) ranging from 2.8 to 4.1 µM, along with a good degree of selectivity index (ranging from 6.1 to 8.9) based on cellular toxicity evaluation compared with standard drug isoniazid (INH). The potent inhibitory actions of fucoxanthin and standard uridine-5'-diphosphate against UGM were recorded to be 98.2% and 99.2%, respectively. TBNAT was potently inactivated by fucoxanthin (half maximal inhibitory concentration (IC50) = 4.8 µM; 99.1% inhibition) as compared to INH (IC50 = 5.9 µM; 97.4% inhibition). Further, molecular docking approaches were achieved to endorse and rationalize the biological findings along with envisaging structure-activity relationships. Since the clinical evidence of the last decade has confirmed the correlation between bacterial infections and autoimmune diseases, in this study we have discussed the linkage between infection with Mtb and autoimmune diseases based on previous clinical observations and animal studies. In conclusion, we propose that fucoxanthin could demonstrate great therapeutic value for the treatment of tuberculosis by acting on multiple targets through a bacteriostatic effect as well as by inhibiting UGM and TBNAT. Such outcomes may lead to avoiding or decreasing the susceptibility to autoimmune diseases associated with Mtb infection in a genetically susceptible host.
- MeSH
- antituberkulotika farmakologie MeSH
- arylamin-N-acetyltransferasa metabolismus MeSH
- autoimunitní nemoci farmakoterapie MeSH
- buněčná stěna účinky léků enzymologie MeSH
- buněčné linie MeSH
- intramolekulární transferasy metabolismus MeSH
- izoenzymy metabolismus MeSH
- karotenoidy farmakologie MeSH
- lidé MeSH
- mikrobiální testy citlivosti metody MeSH
- Mycobacterium tuberculosis účinky léků enzymologie MeSH
- simulace molekulového dockingu metody MeSH
- tuberkulóza farmakoterapie MeSH
- xanthofyly farmakologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Lactobionic acid (LBA) is a newly identified natural polyhydroxy acid that is widely used in the food industry. In this study, the antibacterial effects and underlying mechanism of action of LBA against Staphylococcus aureus were investigated. LBA exhibited significant antibacterial activity against S. aureus with a determination of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of 15 mg/mL and 50 mg/mL, respectively. The Growth curves indicated that LBA directly inhibited the growth of S. aureus. Moreover, LBA induced the leakage of alkaline phosphatase and nucleotides in the culture medium, indicating damage to the integrity of the S. aureus cell wall membrane, which was confirmed by transmission electron microscopy observations. The relative electric conductivity measurements indicated that LBA changed the cell membrane permeability. The preservation effect of LBA was evaluated by quantifying the total number of colonies, total volatile base nitrogen (TVB-N), and thiobarbituric acid reactive substances (TBARS). Overall, these results revealed that LBA exerts its antibacterial activity by breaking down the structure of the bacterial cell wall and membrane, thereby releasing the cellular contents as well as inhibiting protein synthesis, which ultimately lead to cell death. The total number of colonies, the TVB-N value, and the TBARS of cold fresh meat treated with preservatives were significantly lower than those of the control group (P < 0.05). With these antibacterial characteristics, LBA has potential to be used as a safe food additive in the food industry.
- MeSH
- antibakteriální látky farmakologie MeSH
- buněčná membrána účinky léků metabolismus MeSH
- buněčná stěna účinky léků metabolismus MeSH
- disacharidy farmakologie MeSH
- dusík analýza MeSH
- konzervace potravin MeSH
- látky reagující s kyselinou thiobarbiturovou analýza MeSH
- mikrobiální testy citlivosti MeSH
- mikrobiální viabilita účinky léků MeSH
- permeabilita buněčné membrány účinky léků MeSH
- počet mikrobiálních kolonií MeSH
- Staphylococcus aureus účinky léků růst a vývoj MeSH
- Publikační typ
- časopisecké články MeSH
Dermatophytes are the etiological agents of cutaneous mycoses, including the prevalent nail infections and athlete's foot. Candida spp. are opportunistic and emerging pathogens, causing superficial to deeper infections related to high mortality rates. As a consequence of prolonged application of antifungal drugs, the treatment failures combined with multidrug-resistance have become a serious problem in clinical practice. Therefore, novel alternative antifungals are required urgently. δ-Lactones have attracted great interest owing to their wide range of biological activity. This article describes the antifungal activity of synthetic δ-lactones against yeasts of the genus Candida spp. and dermatophytes (through the broth microdilution method), discusses the pathways by which the compounds exert this action (toward the fungal cell wall and/or membrane), and evaluates the toxicity to human leukocytes and chorioallantoic membrane (by the hen's egg test-chorioallantoic membrane). Two of the compounds in the series presented broader spectrum of antifungal activity, including against resistant fungal species. The mechanism of action was related to damage in the fungal cell wall and membrane, with specific target action dependent on the type of substituent present in the δ-lactone structure. The damage in the fungal cell was corroborated by electron microscopy images, which evidenced lysed and completely altered cells after in vitro treatment with δ-lactones. Toxicity was dose dependent for the viability of human leukocytes, but none of the compounds was mutagenic, genotoxic, or membrane irritant when evaluated at higher concentrations than MIC. In this way, δ-lactones constitute a class with excellent perspectives regarding their potential applications as antifungals.
- MeSH
- antifungální látky chemie farmakologie toxicita MeSH
- Arthrodermataceae účinky léků MeSH
- buněčná stěna účinky léků MeSH
- Candida účinky léků MeSH
- laktony chemie farmakologie toxicita MeSH
- leukocyty účinky léků MeSH
- lidé MeSH
- mikrobiální testy citlivosti MeSH
- vyvíjení léků MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
During plant growth and defense, cell cycle activity needs to be coordinated with cell wall integrity. Little is known about how this coordination is achieved. Here, we investigated coordination in Arabidopsis thaliana seedlings by studying the impact of cell wall damage (CWD, caused by cellulose biosynthesis inhibition) on cytokinin homeostasis, cell cycle gene expression and cell shape in root tips. CWD inhibited cell cycle gene expression and increased transition zone cell width in an osmosensitive manner. These results were correlated with CWD-induced, osmosensitive changes in cytokinin homeostasis. Expression of CYTOKININ OXIDASE/DEHYDROGENASE 2 and 3 (CKX2, CKX3), which encode cytokinin-degrading enzymes, was induced by CWD and reduced by osmoticum treatment. In nitrate reductase1 nitrate reductase2 (nia1 nia2) seedlings, CKX2 and CKX3 transcript levels were not increased and cell cycle gene expression was not repressed by CWD. Moreover, established CWD-induced responses, such as jasmonic acid, salicylic acid and lignin production, were also absent, implying a central role of NIA1/2-mediated processes in regulation of CWD responses. These results suggest that CWD enhances cytokinin degradation rates through a NIA1/2-mediated process, leading to attenuation of cell cycle gene expression.
- MeSH
- Arabidopsis cytologie účinky léků genetika MeSH
- benzamidy farmakologie MeSH
- biologické modely MeSH
- buněčná stěna účinky léků metabolismus MeSH
- buněčný cyklus účinky léků genetika MeSH
- cytokininy farmakologie MeSH
- fenotyp MeSH
- homeostáza účinky léků MeSH
- kořeny rostlin cytologie účinky léků růst a vývoj MeSH
- messenger RNA genetika metabolismus MeSH
- nitrátreduktasa metabolismus MeSH
- osmóza MeSH
- proteiny huseníčku metabolismus MeSH
- regulace genové exprese u rostlin * účinky léků MeSH
- semenáček účinky léků genetika MeSH
- sorbitol farmakologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Biogenesis of the plant secondary cell wall involves many important aspects, such as phenolic compound deposition and often silica encrustation. Previously, we demonstrated the importance of the exocyst subunit EXO70H4 for biogenesis of the trichome secondary cell wall, namely for deposition of the autofluorescent and callose-rich cell wall layer. Here, we reveal that EXO70H4-driven cell wall biogenesis is constitutively active in the mature trichome, but also can be activated elsewhere upon pathogen attack, giving this study a broader significance with an overlap into phytopathology. To address the specificity of EXO70H4 among the EXO70 family, we complemented the exo70H4-1 mutant by 18 different Arabidopsis (Arabidopsis thaliana) EXO70 paralogs subcloned under the EXO70H4 promoter. Only EXO70H4 had the capacity to rescue the exo70H4-1 trichome phenotype. Callose deposition phenotype of exo70H4-1 mutant is caused by impaired secretion of PMR4, a callose synthase responsible for the synthesis of callose in the trichome. PMR4 colocalizes with EXO70H4 on plasma membrane microdomains that do not develop in the exo70H4-1 mutant. Using energy-dispersive x-ray microanalysis, we show that both EXO70H4- and PMR4-dependent callose deposition in the trichome are essential for cell wall silicification.
- MeSH
- Arabidopsis účinky léků genetika metabolismus MeSH
- buněčná membrána účinky léků metabolismus MeSH
- buněčná stěna účinky léků metabolismus MeSH
- epidermis rostlin cytologie účinky léků metabolismus MeSH
- fenotyp MeSH
- flagelin farmakologie MeSH
- glukany MeSH
- glukosyltransferasy metabolismus MeSH
- mutace genetika MeSH
- oxid křemičitý metabolismus MeSH
- podjednotky proteinů chemie metabolismus MeSH
- proteinové domény MeSH
- proteiny huseníčku chemie metabolismus MeSH
- regulace genové exprese u rostlin účinky léků MeSH
- trichomy metabolismus MeSH
- upregulace účinky léků MeSH
- vezikulární transportní proteiny chemie metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- MeSH
- bakteriální proteiny genetika metabolismus MeSH
- biofilmy růst a vývoj MeSH
- buněčná membrána účinky léků MeSH
- buněčná stěna účinky léků MeSH
- butanoly metabolismus toxicita MeSH
- Clostridium účinky léků genetika metabolismus MeSH
- fylogeneze MeSH
- genom bakteriální MeSH
- mutageneze MeSH
- průmyslová mikrobiologie metody MeSH
- transkripční faktory genetika metabolismus MeSH
- výpočetní biologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
