G-Quadruplexes have been proved to exist in 5′-untranslated region (5′-UTR), promoter, intron and exon regions of many human genes. Here we report an intramolecular G-quadruplex formed by a G-rich ...sequence in the 3′-flanking region of signal transducers and activators of transcription 3 (STAT3) gene. The results showed that this G-rich sequence could affect the expression of STAT3. When the STAT3 G-quadruplex was stabilized by a novel non-planar ligand Cepharanthine (
CEP), the decreased expression of STAT3 was observed in primary cultured cardiomyocytes. We also demonstrated that the down-regulation of STAT3 was most likely occurred at the transcriptional level. Our results provide a new clue for studying the G-quadruplex formation, recognition and function in the 3′-flanking region of gene.
Automated online SPE‐HPLC‐MS was established for the determination of deca‐bromodiphenyl ether in human serum. The online SPE with large volume injection was utilized to enhance the sensitivity. ...Online SPE with dilution line greatly decreased matrices effect, which enabled serum samples to be injected directly into pre‐column. Washing line was designed for the system to solve the serious residual phenomenon and reduce the risk of sample wastage and contamination. Under the optimized conditions, the linear of the method was in the range 0.1–10 ng/mL with the LOD of 0.026 ng/mL. The recoveries of serum samples spiked with deca‐bromodiphenyl ether at 0.5 ng/mL was in the range from 83.30 to 102.7% with RSD in interday less than 8.67%. The satisfactory results demonstrated that the method of online sample pretreatment and cleanup recycle were reliable for human serum analysis.
Display omitted
•GC × GC-ToF-MS was a better choice to discriminate the volatile profiles of M. sextelata when compared with GC–MS and GC-IMS.•Alcohols, heterocycles, and ketones were the VOCs most ...affected by the drying methods.•Freeze-drying was beneficial to maintain key flavor substances of M. sextelata, such as C8 compounds and benzaldehyde.•Hot air-drying promoted the production of heterocycles and ketones with roasted flavor.
Morchella sextelata is a precious and popular commercial edible fungus that was developed recently in China. This research aimed to characterize the volatile profiles of M. sextelata under three dehydration methods (freeze, hot air, and natural air drying). Comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry (GC × GC-ToF-MS) was shown to the best choice to discriminate the volatile profiles of M. sextelata Characteristic flavor substances of M. sextelata were eight-carbon-containing (C8) compounds, hexanal, 2(5 h)-furanone, and benzaldehyde. Drying methods had significant influences on the volatile flavor profiles of M. sextelata, and 104 differential compounds were screened by multivariate statistical analysis. Freeze-dried samples had the most abundant volatile compounds and maintained more alcohols, ketones, aldehydes, and esters described as mushroom, sweet, and green flavor, like 1-octen-3-ol, 1-octen-3-one, nonanal, 2,3-butanedione, and so on. Hot air-drying promoted the production of heterocycles and ketones with roasted flavor due to the thermalreaction, such as 2-cyclohexen-1-one, furan, 3-phenyl-, etc. Natural air-drying resulted in acids releasing an unpleasant flavor, e.g., acetic acid, 2-methylbutanoic acid, etc. Overall, thermal reaction combined with vacuum conditions might be suitable for maintaining and enriching the aroma flavor of dried true morels.
Strain CN29
T
, isolated from the stem of 5- to 6-year-old
Populus tomentosa
in Shandong, China, was characterized using a polyphasic taxonomic approach. Cells of CN29
T
were Gram-stain negative, ...aerobic, nonspore-forming, and nonmotile coccoid. Growth occurred at 20–37 °C, pH 4.0–9.0 (optimum, pH 6.0), and with 0–1% NaCl (optimum, 1%). Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain CN29
T
was closely related to members of the genus
Roseomonas
and closest to
Roseomonas pecuniae
N75
T
(96.6%). This classification was further supported by phylogenetic analysis using additional core genes. The average nucleotide identity and digital DNA‒DNA hybridization values between strain CN29
T
and
Roseomonas populi
CN29
T
were 82.7% and 27.8%, respectively. The genome size of strain CN29
T
was 5.87 Mb, with a G + C content of 70.9%. The major cellular fatty acids included summed feature 8 (C
18:1
ω7c/C
18:1
ω6c), C
19:0
cyclo ω8c and C
16:0
. The major respiratory quinone was Q-10. The polar lipids were phosphatidylcholine, aminolipid, phosphatidylglycerol, and diphosphatidylglycerol. Strain CN29
T
can utilize acetate as a carbon source for growth and metabolism. Additionally, it contains acid phosphatase (2-naphthyl phosphate), which catalyzes the hydrolysis of phosphoric monoesters. The CN29
T
strain contains several genes, including
maeB
,
gdhB
, and
cysJ
, involved in carbon, nitrogen, and sulfur cycling. These findings suggest that the strain may actively participate in ecosystem cycling, leading to soil improvement and promoting the growth of poplar trees. Based on the phylogenetic, phenotypic, and genotypic characteristics, strain CN29
T
is concluded to represent a novel species of the genus
Roseomonas
, for which the name
Roseomonas populi
sp. nov. is proposed. The type strain is CN29
T
(= JCM 35579
T
= GDMCC 1.3267
T
).
Pdi1p (protein-disulfide isomerase) is a folding assistant of the endoplasmic reticulum (ER) that catalyzes disulfide formation and the isomerization of incorrect disulfides. Its disulfide forming ...activity is its essential function in Saccharomyces cerevisiae. A truncation mutant (Pdi1a′) that is competent in disulfide formation but deficient in catalyzing isomerization has only a small effect on growth, although the maturation of isomerase-requiring substrates (carboxypeptidase Y) is impaired (Xiao, R., Wilkinson, B., Solovyov, A., Winther, J. R., Holmgren, A., Lundstrom-Ljung, J., and Gilbert, H. F. (2004) J. Biol. Chem. 279, 49780–49786). We show here that there are multiple ways to compensate for defects in disulfide formation and isomerization in the ER. Genes of the unfolded protein response are induced, and deletions of the nonessential IRE1 or HAC1 genes are synthetically lethal. Diploid synthetic lethality analysis by microarray (dSLAM) using PDIa′ and a temperature-sensitive mutant of PDIa′ as query mutations reveals a group of 130 synthetically lethal genes. Only 10 of these correspond to genes clearly associated with the unfolded protein response. More than half are involved in vesicle traffic, not only out of and into the ER but anterograde and retrograde traffic from most cellular compartments. This suggests that defects in protein maturation in one intracellular compartment may be compensated for by adjusting vesicular traffic patterns throughout the cell.
Ecological ternary cements containing phosphogypsum (ECP) were prepared with powders of phosphogypsum (PG), fly ash (FA) and portland cement (PC). The evolution mechanism of the hydration product ...structure was characterized through macro and micro experiments.The thermodynamic characteristics of solid phase, solid solution phase and aqueous solution in process of hydration about phosphogypsum-fly ash-cement ternary cementitious system were studied based on the Gibbs-free-energy C-S-H thermodynamic model and GEM-Selektor software, and compared with experimental results. The results show that in the hydration reaction the thermodynamic interaction between mineral single-phase and hydration products plays an important role in the spatio-temporal distribution of ions in the cementitious system. The values of CaO, SiO2Hand H2Ohyd gradually increased with the increase of Ca/Si ratio, while the values of CaOext and H2OOH showed a positive proportional relationship, and the values of SiO2H and SiO2 showed an inverse proportional relationship. GEM-Selektor is accurate in the simulation calculation of the total amount of AFt and AFm mineral phases which quantitatively analysis the correlation between C-S-H gels formation and C3S with complex decomposition ion groups.
Display omitted
•The thermodynamic characteristics were studied based on the C-S-H thermodynamic model.•GEM-Selektor is accurate in the simulation calculation of the total amount of AFt and AFm mineral phases.•The evolution law of hydration product structure mainly is manifested that PG generates SiO42- ion by ionization, and combined with Si-O-Si, Al-O-Al, Al-O and Si-O covalent bonds broken by PC. At the same time, it reunited with SiO42- and AlO45- ions ionized by FA, and polymerized to form stable C-S-H and C-A-S-H.
The spindle checkpoint monitors mitotic spindle integrity and the attachment of kinetochores to the spindle. Upon sensing a defect the checkpoint blocks cell cycle progression and thereby prevents ...chromosome missegregation. Previous studies in budding yeast show that the activated spindle checkpoint inhibits the onset of anaphase by an unknown mechanism. One possible target or the spindle checkpoint is anaphase promoting complex (APC), which controls all postmetaphase events that are blocked by spindle checkpoint activation. We have isolated mad2, a spindle checkpoint component in fission yeast, and shown that mad2 overexpression activates the checkpoint and causes a cell cycle arrest at the metaphase-to-anaphase transition. In addition to the observation that mad2-induced arrest can he partially relieved by mitosis-promoting factor inactivation, we present genetic evidence consistent with the hypothesis that the spindle checkpoint imposes a cell cycle arrest by inhibiting APC-dependent proteolysis
Schizosaccharomyces pombe is an excellent organism in which to study cytokinesis as it divides by medial fission using an F-actin contractile ring. To enhance our understanding of the cell division ...process, a large genetic screen was carried out in which 17 genetic loci essential for cytokinesis were identified, 5 of which are novel. Mutants identifying three genes, rng3(+), rng4(+), and rng5(+), were defective in organizing an actin contractile ring. Four mutants defective in septum deposition, septum initiation defective (sid)1, sid2, sid3, and sid4, were also identified and characterized. Genetic analyses revealed that the sid mutants display strong negative interactions with the previously described septation mutants cdc7-24, cdc11-123, and cdc14-118. The rng5(+), sid2(+), and sid3(+) genes were cloned and shown to encode Myo2p (a myosin heavy chain), a protein kinase related to budding yeast Dbf2p, and Spg1p, a GTP binding protein that is a member of the ras superfamily of GTPases, respectively. The ability of Spg1p to promote septum formation from any point in the cell cycle depends on the activity of Sid4p. In addition, we have characterized a phenotype that has not been described previously in cytokinesis mutants, namely the failure to reorganize actin patches to the medial region of the cell in preparation for septum formation.
A Gram-stain-negative, rod-shaped, non-flagellated, pale-yellow bacterium, designated GHJ8
T
, was isolated from the rhizosphere soil of
Ulmus pumila
L., Shanxi Province, China. Growth occurred at ...20–37 °C (optimum, 28 °C), pH 6.0–11.0 (optimum, pH 8.0), and 0–1% NaCl (optimum, 0%). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain GHJ8
T
was related to members of the genus
Luteolibacter
, and close to
Luteolibacter flavescens
GKX
T
(98.5%),
Luteolibacter luteus
G-1-1-1
T
(97.3%),
Luteolibacter arcticus
MC 3726
T
(97.2%), and
Luteolibacter marinus
NBU1238
T
(96.0%). The genome size of strain GHJ8
T
was 6.2 Mbp, with a G + C content of 62.5%. Genomic mining revealed that the strain contained antibiotic resistance genes and secondary metabolic gene clusters, indicating that it had adaptation mechanisms to environmental stress. Comparative genomic analyses clearly separated strain GHJ8
T
from the recognized species of the genus
Luteolibacter
based on average nucleotide identity (ANI) and digital DNA–DNA hybridization (dDDH) values below the thresholds for species delineation. The major cellular fatty acids were iso-C
14:0
(30.8%), C
16:1
ω
9
c
(23.0%), C
16:0
(17.3%), and C
14:0
(13.4%). The quinone system was composed of the major menaquinones MK-8, MK-9, and MK-10, and the principal polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, an unidentified aminophospholipid, an unidentified glycolipid, two unidentified phospholipids, and three unidentified lipids. Based on its phenotypic and genotypic properties and phylogenetic inference, strain GHJ8
T
is a novel species of the genus
Luteolibacter
, for which the name
Luteolibacter rhizosphaerae
sp. nov. is proposed. The type strain is GHJ8
T
(= GDMCC 1.2160
T
= KCTC 82452
T
= JCM 34400
T
).
The loop B3 of glycoside hydrolase family 7 (GH7) endoglucanases is confined into long and short types. TtCel7 is a thermophilic GH7 endoglucanase from Thermothelomyces thermophilus ATCC 42464 with a ...long loop B3. TtCel7 was distinct for the excellent thermostability (>30 % residual activity after 1-h incubation at 90 °C). The catalytic efficiency was reduced by removing the disulfide bond in loop B3 (C220A) and truncated the loop B3 (B3cut). However, B3cut exhibited improved thermostability, the remaining enzyme activity increased by 39 %–171 % compared toTtCel7 when treated at 70–90 °C for 1-h. Based on the analysis of molecular dynamics simulation, both loops B1 and A3 of B3cut swing toward the catalytic center, which contributed to the reduced cleft-space and increased structure-rigidity. Conversely, the deletion of disulfide bond resulted in a reduction of structural rigidity in C220A. Through structure-directed enzyme modulation, this study has identified two structural elements that are related to the catalysis and thermostability of TtCel7. The loop B3 of TtCel7 possibly stretches the catalytic pocket, thereby increases the openness of the catalytic tunnel and enhancing flexibility for efficient catalysis. Additionally, the disulfide bond within loop B3 serves to enhance structural stability and maintain a heightened level of activity.
•A novel thermophilic GH7 endoglucanase (TtCel7) was identified and characterized.•Variants were designed to study the role of loop B3 in catalytic efficiency and thermostability.•Loop B3 in TtCel7 stretches the catalytic pocket more openly, enhancing protein flexibility for efficient catalysis.•Disulfide bond in loop B3 serves to enhance structural stability and maintain a heightened level of activity.
PDF
