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Rationale: Posterior disc displacement (PDD) is an uncommon condition in which disc tissue is located between the posterior surface of the condyle and post-glenoid tubercle. The etiopathogenesis of this condition is idiopathic. There are different predisposing factors in the literature which are consistent with the presented case such as lack of anterior prominence of the disc, thinning of the posterior zone of the disc and perforation of the disc. Patient Concerns: We report an uncommon temporomandibular joint (TMJ) arthropathy case of a 33-year-old female patient, who presented with long-standing TMJ pain associated with limited mouth opening. Diagnosis: The patient was diagnosed with non-reducible PDD of TMJ bilaterally. Treatment: Open surgery of TMJ (Discopexy) was the choice of treatment to release and mobilise discs. Outcomes: A noticeable increase in mouth opening without pain in TMJ area was achieved immediately after surgery and remained stable during periodic follow-ups. Take-away Lessons: The importance of magnetic resonance imaging as a diagnostic tool for arthropathy, to determine the proper management is essential. Moreover, the root of the helix inter tragus notch incision presents an advantage of open surgery of TMJ which results in immediate outcome with limited complications.
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One of the key events in autophagy is the formation of a double-membrane phagophore, and many regulatory mechanisms underpinning this remain under investigation. WIPI2b is among the first proteins to be recruited to the phagophore and is essential for stimulating autophagy flux by recruiting the ATG12-ATG5-ATG16L1 complex, driving LC3 and GABARAP lipidation. Here, we set out to investigate how WIPI2b function is regulated by phosphorylation. We studied two phosphorylation sites on WIPI2b, S68 and S284. Phosphorylation at these sites plays distinct roles, regulating WIPI2b's association with ATG16L1 and the phagophore, respectively. We confirm WIPI2b is a novel ULK1 substrate, validated by the detection of endogenous phosphorylation at S284. Notably, S284 is situated within an 18-amino acid stretch, which, when in contact with liposomes, forms an amphipathic helix. Phosphorylation at S284 disrupts the formation of the amphipathic helix, hindering the association of WIPI2b with membranes and autophagosome formation. Understanding these intricacies in the regulatory mechanisms governing WIPI2b's association with its interacting partners and membranes, holds the potential to shed light on these complex processes, integral to phagophore biogenesis.
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To explore the mechanism of Liangfang Wenjing Decoction regulating coiled-coil-helix coiled-coil-helix domain containing 4(CHCHD4) in the treatment of hypoxia on endometriosis(EMs) with cold coagulation and blood stasis. The rat model of cold coagulation and blood stasis syndrome was prepared by the ice-water bath method, and then the EMs model was established by autologous intimal transplantation. The rats were randomly divided into model group, low, medium, and high(4.7, 9.4, and 18.8 g·kg~(-1)) dose groups of Liangfang Wenjing Decoction, Shaofu Zhuyu Decoction group, and sham group, with 10 rats in each group. The rats were given intragastric administration for four weeks. During the modeling, the general condition and vaginal smear of rats were observed, and the blood flow of ears and uterus were detected by laser speckle contrast imaging(LSCI) to judge the syndrome of cold coagulation and blood stasis. After the administration, the general condition of the rats was observed, and the area of ectopic lesions was measured by caliper. The localization and expression of CHCHD4 and hypoxia inducible factors-1α(HIF-1α) were detected by immunohistochemistry, and the mRNA and protein expressions of CHCHD4 and HIF-1α were detected by real-time quantitative polymerase chain reaction(RT-qPCR) and Western blot. The primary culture of ectopic endometrial stromal cells(ESCs) from EMs patients was performed, and the CHCHD4 overexpression plasmid was constructed and transfected to establish the ESCs model of CHCHD4 overexpression. The cells were divided into the control group, CHCHD4 overexpression group, CHCHD4 overexpression+control serum group, and CHCHD4 overexpression+Liangfang Wenjing Decoction serum group. The protein expression of CHCHD4 and HIF-1α was detected by Western blot, and the glucose consumption and lactic acid level were detected. The cell proliferation was detected by MTT assay. The experiment found that compared with normal rats, the modeling rats showed symptoms of cold coagulation and blood stasis, such as mental malaise, reduced diet and drinking water, disordered estrous cycle, and blocked blood circulation in ears and uterine microvessels. Compared with the sham group, the ectopic lesions in the model group were uplifted, and the mRNA and protein expressions of CHCHD4 and HIF-1α were significantly increased(P<0.05). Compared with the model group, the symptoms of cold coagulation and blood stasis in each treatment group were improved, and the area of ectopic lesions was significantly reduced(P<0.05 or P<0.01). The mRNA and protein expression levels of CHCHD4 and HIF-1α were significantly decreased(P<0.05 or P<0.01). In the cell model, compared with the control group, the expression of CHCHD4, HIF-1α protein, glucose consumption, lactic acid level, and cell proliferation activity in the CHCHD4 overexpression group were significantly increased(P<0.01). Compared with the CHCHD4 overexpression group, there was no significant change in each index in the control serum group, while the protein expression of CHCHD4 and HIF-1α in the Liangfang Wenjing Decoction serum group was decreased significantly(P<0.05 or P<0.01). The glucose consumption, lactic acid level, and cell proliferation activity decreased significantly(P<0.01). It can be seen from the above that the therapeutic effect of Liangfang Wenjing Decoction on EMs with cold coagulation and blood stasis might be related to reducing the expression of CHCHD4 and then improving the hypoxia of ectopic lesions and ectopic ESCs.
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Medicamentos de Ervas Chinesas , Endometriose , Hipóxia , Ratos Sprague-Dawley , Animais , Feminino , Endometriose/tratamento farmacológico , Endometriose/genética , Endometriose/metabolismo , Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/administração & dosagem , Ratos , Humanos , Hipóxia/genética , Hipóxia/tratamento farmacológico , Hipóxia/fisiopatologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismoRESUMO
The Boerdijk-Coxeter helix (BC helix or tetrahelix) is a linear stacking of regular tetrahedra. Although the BC helix exhibits an aperiodic nature, structures resembling the BC helix with periodicity are found in materials. To understand such structures, we considered a modification of the BC helix to introduce periodicity. By adjusting the relative rotation of adjacent tetrahedra, we demonstrated that periodic arrangements consisting of 8, 11, and 14 tetrahedra have appearances similar to that of the BC helix.
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In the manufacture of soft gelatin capsules using a rotary-die encapsulation machine, the formation of ribbons at the cooling drums and their subsequent mechanical performance are key attributes for a smooth machinability. In this paper we present the results of a comprehensive investigation of the intricate impact of the cooling drum temperature in the range between 5 and 25⯰C on the mechanical and the microstructural properties of a highly concentrated gelatin formulation (40â¯% w/w) typically used in soft capsule manufacture. The study demonstrates that the temperature at the cooling drums strongly affects the gelation kinetics, the gel elasticity and the tensile strength of the ribbons. The temperature correlates linearly with the storage modulus G' under low shear deformation, i.e. the lower the temperature of the gel, the higher the gel elasticity. A reverse linear relationship was found for the temperature-dependent ultimate tensile strength (UTS) of the gelatin ribbons, i.e. a higher drum temperature leads to a higher UTS. This inverse effect of the ageing temperature on G' and UTS can be explained by temperature-induced microstructural differences within the gel network, as indicated by FTIR spectroscopy and Differential Scanning Calorimetry (DSC) measurements. Lower ageing temperatures result in a higher number of triple helical junction zones with fewer and/or weaker hydrogen bonds, which translate into a higher gel elasticity under low shear deformation, but a lower resilience of the ribbons against rupture in tensile testing. At higher temperatures, fewer but longer and/or more thermostable triple helical links in the gel network enhance the stability of the ribbons against tensile stress. In summary, the results clearly reveal that a detailed understanding of the complex relationship between the drum temperature, the gel network structure and the mechanical properties of gelatin ribbons is essential for process optimization.
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Human Hippo signaling pathway is an evolutionarily conserved regulator network that controls organ development and has been implicated in various cancers. Transcriptional enhanced associate domain-4 (TEAD4) is the final nuclear effector of Hippo pathway, which is activated by Yes-associated protein (YAP) through binding to two separated YAP regions of α1-helix and Ω-loop. Previous efforts have all been addressed on deriving peptide inhibitors from the YAP to target TEAD4. Instead, we herein attempted to rationally design a so-called 'YAP helixα1-trap' based on the TEAD4 to target YAP by using dynamics simulation and energetics analysis as well as experimental assays at molecular and cellular levels. The trap represents a native double-stranded helical hairpin covering a specific YAP-binding site on TEAD4 surface, which is expected to form a three-helix bundle with the α1-helical region of YAP, thus competitively disrupting TEAD4-YAP interaction. The hairpin was further stapled by a disulfide bridge across its two helical arms. Circular dichroism characterized that the stapling can effectively constrain the trap into a native-like structured conformation in free state, thus largely minimizing the entropy penalty upon its binding to YAP. Affinity assays revealed that the stapling can considerably improve the trap binding potency to YAP α1-helix by up to 8.5-fold at molecular level, which also exhibited a good tumor-suppressing effect at cellular level if fused with TAT cell permeation sequence. In this respect, it is considered that the YAP helixα1-trap-mediated blockade of Hippo pathway may be a new and promising therapeutic strategy against cancers.
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Proteínas Adaptadoras de Transdução de Sinal , Antineoplásicos , Proteínas de Ligação a DNA , Simulação de Dinâmica Molecular , Proteínas Musculares , Fatores de Transcrição de Domínio TEA , Fatores de Transcrição , Proteínas de Sinalização YAP , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo , Fatores de Transcrição/antagonistas & inibidores , Humanos , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/metabolismo , Antineoplásicos/farmacologia , Antineoplásicos/química , Proteínas Musculares/química , Proteínas Musculares/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/química , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Dissulfetos/química , Dissulfetos/farmacologia , Ligação Proteica , Sítios de Ligação , Linhagem Celular Tumoral , Desenho Assistido por Computador , Desenho de FármacosRESUMO
BACKGROUND: The investigations of snail slime and its possible biological activities have been performed recently. AIM: This study aimed to evaluate the properties of Helix aspersa snail slime (HAS), and carotenoids-fortified slime (HASC). METHODS: Snails were fed with carrots for 10 days. Slime was collected and extracted using water. Saponins identification, antioxidant, collagenase, and tyrosinase enzyme inhibition activities, carotenoids, total phenols, and flavonoids content, were determined. UHPLC-MS/MS analysis was performed for phytochemical characterization. RESULTS: Saponins were detected in the HAS extract only. However, HASC was shown to contain a higher carotenoid content than HAS (29.51 ± 0.4 vs. 18.11 ± 0.2 µg/g). similarly, total phenolic and flavonoid content were higher for the the HASC extract compared to the HAS (182.3 ± 5.2 vs. 150.28 ± 3.3 mg/g equivalent to gallic acid), and (77.62 ± 1.2 vs. 14.19 ± 0.9 mg/g equivalent to quercetin). As expected, the HASC extract exhibited higher antioxidant activity compared to the HAS, using DPPH and the ABTS assays (IC50 = 7.75 ± 0.14 vs. 20.1 ± 0.4 µg/mL), and (IC50 = 7.6 ± 0.26 vs. 19.57 ± 1.4 µg/mL). UHPLC-MS/MS analysis revealed the presence of several phytocomponents of which, hexadecanoic acid and ascorbic acid, were observed in the HASC extract. Furthermore, HASC extract exhibited superior inhibitory activity compared to HAS against collagenase and tyrosinase enzymes (IC50 = 8.4 ± 1.19 vs. 15.3 ± 1.12 µg/mL) and (IC50 = 30.1 ± 0.91 vs. 35 ± 1.3 µg/mL). CONCLUSION: These findings highlight the potential of HASC as a valuable ingredient in various pharmaceutical applications, due to their content of various phenolic, antioxidants, carotenoids, hexadecanoic, and ascorbic acids. The latter is well known for its great cosmeceutical applications used for slowing the process of skin aging.
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BACKGROUND: Recent studies have reported that helix B surface polypeptide (HBSP), an erythropoietin derivative, exhibits strong tissue protective effects, independent of erythropoietic effects, in a renal ischemia-reperfusion (IR) injury model. Meanwhile, the transforming growth factor-ß (TGF-ß) superfamily member glial cell line-derived neurotrophic factor (GDNF) demonstrated protective effect on podocytes in vitro. Using a rat puromycin aminonucleoside nephropathy (PAN) model, this study observed the renal protective effect of HBSP and investigated its renal protective effect on podocytes and mechanism related to GDNF. METHODS: Rats nephropathy model was induced by injection of 60 mg/kg of PAN via the tail vein. Rats in the PAN + HBSP group were injected intraperitoneally with HBSP (8 nmol/kg) 4 h before the model was induced, followed by intraperitoneal injections of HBSP once every 24 h for 7 consecutive days. The 24-hour urinary protein level was measured once every other day, and blood and renal tissue samples were collected on the 7th day for the examination of renal function, complete blood count, renal pathological changes and the expression levels of GDNF. RESULTS: Compared with the control group, the PAN nephropathy rat model showed a large amount of urinary protein. The pathological manifestations were mainly extensive fusion and disappearance of foot processes, along with vacuolar degeneration of podocytes and their separation from the glomerular basement membrane. GDNF expression was upregulated. Compared with the PAN + vehicle group, the PAN + HBSP group showed decreased urinary protein (p < 0.05). Pathological examination revealed ameliorated glomerular injury and vacuolar degeneration of podocytes. The expression of GDNF in the PAN nephropathy group was increased, when compared with the control group. The greatest expression of GDNF observed in the PAN + HBSP group (p < 0.05). CONCLUSIONS: The expression of GDNF in the kidney of PAN rat model was increased. HBSP reduced urinary protein, ameliorated pathological changes in renal podocytes, increased the expression of GDNF in the PAN rat model. HBSP is likely to exert its protective effects on podocytes through upregulation of GDNF expression.
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Modelos Animais de Doenças , Fator Neurotrófico Derivado de Linhagem de Célula Glial , Nefropatias , Podócitos , Puromicina Aminonucleosídeo , Ratos Sprague-Dawley , Animais , Ratos , Podócitos/efeitos dos fármacos , Podócitos/patologia , Podócitos/metabolismo , Masculino , Fator Neurotrófico Derivado de Linhagem de Célula Glial/metabolismo , Nefropatias/induzido quimicamente , Nefropatias/prevenção & controle , Nefropatias/patologia , Rim/patologia , Rim/efeitos dos fármacos , Traumatismo por Reperfusão/prevenção & controle , Traumatismo por Reperfusão/metabolismo , Eritropoetina , Fragmentos de PeptídeosRESUMO
Sexual reproduction is crucial for increasing the genetic diversity of populations and providing overwintering structures, such as perithecia and associated tissue, in the destructive plant pathogenic fungus Fusarium graminearum. While mating-type genes serve as master regulators in fungal sexual reproduction, the molecular mechanisms underlying this process remain elusive. Winged-helix DNA-binding proteins are key regulators of embryogenesis and cell differentiation in higher eukaryotes. These proteins are implicated in the morphogenesis and development of several fungal species. However, their involvement in sexual reproduction remains largely unexplored in F. graminearum. Here, we investigated the function of winged-helix DNA-binding proteins in vegetative growth, conidiation, and sexual reproduction, with a specific focus on the FgWING27, which is highly conserved among Fusarium species. Deletion of FgWING27 resulted in an abnormal pattern characterized by a gradual increase in the expression of mating-type genes during sexual development, indicating its crucial role in the stage-specific genetic regulation of MAT genes in the late stages of sexual development. Furthermore, using chromatin immunoprecipitation followed by sequencing analysis, we identified Fg17056 as a downstream gene of Fgwing27, which is essential for sexual reproduction. These findings underscore the significance of winged-helix DNA-binding proteins in fungal development and reproduction in F. graminearum, and highlight the pivotal role of Fgwing27 as a core genetic factor in the intricate genetic regulatory network governing sexual reproduction.IMPORTANCEFusarium graminearum is a devastating plant pathogenic fungus causing significant economic losses due to reduced crop yields. In Fusarium Head Blight epidemics, spores produced through sexual and asexual reproduction serve as inoculum, making it essential to understand the fungal reproduction process. Here, we focus on winged-helix DNA-binding proteins, which have been reported to play crucial roles in cell cycle regulation and differentiation, and address their requirement in the sexual reproduction of F. graminearum. Furthermore, we identified a highly conserved protein in Fusarium as a key factor in self-fertility, along with the discovery of its direct downstream genes. This provides crucial information for constructing the complex genetic regulatory network of sexual reproduction and significantly contribute to further research on sexual reproduction in Fusarium species.
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The linear undecapeptide BP52 was previously reported to have antibacterial activity against phytopathogenic bacteria species. Due to the structural similarities to naturally occurring cationic helical antimicrobial peptides, it was speculated that this peptide could potentially target microbial pathogens and cancer cells found in mammals. Consequently, this study aims to further investigate the structural and biological properties of this peptide. Our findings indicate that BP52 exhibits strong antimicrobial and anticancer activity while displaying relatively low levels of hemolytic activity. Hence, this study suggests that BP52 could be a potential lead compound for drug discovery against infectious diseases and cancer. Besides, new insights into the relationships between the structure and the multifunctional properties of antimicrobial peptides were also explored.
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BACKGROUND: Collagen triple helix repeat containing-1 (CTHRC1), an extracellular matrix protein, is highly expressed in hepatocellular carcinoma (HCC) and linked to poor prognosis. Nevertheless, the precise mechanism of CTHRC1 in HCC is unclear. METHODS: Agena MassARRAY® Methylation Analysis assessed the methylation level of CTHRC1 in the promoter region. Functional assays were conducted to investigate the effects of CTHRC1 knockdown in Hep3B2.1 cells. RNA sequencing identified differentially expressed genes and lncRNAs associated with angiogenesis after CTHRC1 knockdown. Furthermore, differential alternative splicing (AS) and gene fusion events were analyzed using rMATS and Arriba. RESULTS: In HCC cell lines, CTHRC1 was highly expressed and associated with hypomethylation. Downregulation of CTHRC1 inhibited Hep3B2.1 cell proliferation, migration, and invasion, blocked cells in the G1/S phase, and promoted apoptosis. We obtained 34 mRNAs and 7 lncRNAs differentially expressed between the NC and CTHRC1 inhibitor groups. Additionally, we found 4 angiogenesis-related mRNAs and lncRNAs significantly correlated with CTHRC1. RT-qPCR results showed that knockdown of CTHRC1 in Hep3B2.1 cells resulted in significantly aberrant expression of CXCL6, LINC02127, and AC020978.8. Moreover, the role of CTHRC1 in HCC development may be associated with events, like 12 AS events and 5 pairs of fusion genes. CONCLUSIONS: High expressed CTHRC1 is associated with hypomethylation and may promote HCC development, involving events like angiogenesis, alternative splicing, and gene fusion.
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The experimental challenges posed by integral membrane proteins hinder molecular understanding of transmembrane signaling mechanisms. Here, we exploited protein crosslinking assays in living cells to follow conformational and dynamic stimulus signals in Tsr, the Escherichia coli serine chemoreceptor. Tsr mediates serine chemotaxis by integrating transmembrane serine-binding inputs with adaptational modifications of a methylation helix bundle to regulate a signaling kinase at the cytoplasmic tip of the receptor molecule. We created a series of cysteine replacements at Tsr residues adjacent to hydrophobic packing faces of the bundle helices and crosslinked them with a cell-permeable, bifunctional thiol-reagent. We identified an extensively crosslinked dynamic junction midway through the methylation helix bundle that seemed uniquely poised to respond to serine signals. We explored its role in mediating signaling shifts between different packing arrangements of the bundle helices by measuring crosslinking in receptor molecules with apposed pairs of cysteine reporters in each subunit and assessing their signaling behaviors with an in vivo kinase assay. In the absence of serine, the bundle helices evinced compact kinase-ON packing arrangements; in the presence of serine, the dynamic junction destabilized adjacent bundle segments and shifted the bundle to an expanded, less stable kinase-OFF helix-packing arrangement. An AlphaFold 3 model of kinase-active Tsr showed a prominent bulge and kink at the dynamic junction that might antagonize stable structure at the receptor tip. Serine stimuli probably inhibit kinase activity by shifting the bundle to a less stably-packed conformation that relaxes structural strain at the receptor tip, thereby freezing kinase activity.
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Soluble N-ethylmaleimide-sensitive factor Attachment protein REceptor (SNARE) proteins catalyze the fusion process of vesicles with target membranes in eukaryotic cells. To do this, they assemble in a zipper-like fashion into stable complexes between the membranes. Structural studies have shown that the complexes consist of four different helices, which we subdivide into Qa-, Qb-, Qc-, and R-helix on the basis of their sequence signatures. Using a combination of biochemistry, modeling and molecular dynamics, we investigated how the four different types are arranged in a complex. We found that there is a matching pattern in the core of the complex that dictates the position of the four fundamental SNARE types in the bundle, resulting in a QabcR complex. In the cell, several different cognate QabcR-SNARE complexes catalyze the different transport steps between the compartments of the endomembrane system. Each of these cognate QabcR complexes is compiled from a repertoire of about 20 SNARE subtypes. Our studies show that exchange within the four types is largely tolerated structurally, although some non-cognate exchanges lead to structural imbalances. This suggests that SNARE complexes have evolved for a catalytic mechanism, a mechanism that leaves little scope for selectivity beyond the QabcR rule.
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Proteínas SNARE , Proteínas SNARE/química , Proteínas SNARE/metabolismo , Humanos , Modelos Moleculares , Simulação de Dinâmica Molecular , AnimaisRESUMO
BACKGROUND: Mycotoxins, a class of secondary metabolites produced by molds, are widely distributed in nature and are very common in food contamination. Aflatoxin B1 (AFB1) is a highly stable natural mycotoxin, and many agricultural products are easily contaminated by AFB1, it is important to establish a sensitive and efficient AFB1 detection method for food safety. The fluorescence aptamer sensor has shown satisfactory performance in AFB1 detection, but most of the fluorescence aptasensors are not sensitive enough, so improving the sensitivity of the aptasensor becomes the focus of this work. RESULTS: Herein, an innovative fluorescent aptasensor for AFB1 detection which is based on catalytic hairpin assembly (CHA) and rolling circle amplification (RCA) driven by triple helix molecular switch (THMS) is proposed. A functional single-strand with an AFB1 aptamer, here called an APF, is first designed to lock onto the signal transduction probe (STP), which separates from THMS when target AFB1 is present. Subsequently, STP initiates the RCA reaction along the circular probe, syntheses macro-molecular mass products through repeated triggering sequences, triggers the CHA reaction to produce a large number of H1-H2 structures, which causes FAM to move away from BHQ-1 and recover its fluorescence signal. The fluorescence signal from FAM at 520 nm was collected as the signal output of aptasensor in this work. With high amplification efficiency of RCA and CHA of the fluorescence sensor, resulting in a low LOD value of 2.95 pg mL-1(S/N = 3). SIGNIFICANCE: The successful establishment of the sensor designed in this work shows that the cascade amplification reaction is perfectly applied in the fluorescent aptamer sensor, and the signal amplification through the reaction between DNA strands is a simple and efficient method. In addition, it's also important to remember that the aptasensor can detect other targets only by changing the sequence of the aptamer, without redesigning other DNA sequences in the reaction system.
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Aflatoxina B1 , Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Corantes Fluorescentes , Técnicas de Amplificação de Ácido Nucleico , Aflatoxina B1/análise , Aflatoxina B1/química , Aptâmeros de Nucleotídeos/química , Técnicas de Amplificação de Ácido Nucleico/métodos , Técnicas Biossensoriais/métodos , Corantes Fluorescentes/química , Limite de Detecção , Espectrometria de Fluorescência , Contaminação de Alimentos/análise , CatáliseRESUMO
BACKGROUND AND AIMS: SPATULA (SPT) encodes a basic Helix-Loop-Helix transcription factor in Arabidopsis thaliana that functions in the development of the style, stigma and replum tissues, all of which arise from the carpel margin meristem (CMM) of the gynoecium. Here, we use a comparative approach to investigate the evolutionary history of SPT and identify changes that potentially contributed to its role in gynoecium development. METHODS: We investigate SPT's molecular and functional evolution using phylogenetic reconstruction, yeast-2-hybrid analyses of protein-protein interactions, microarray-based analyses of protein-DNA interactions, plant transformation assays, RNA in-situ hybridization, and in-silico analyses of promoter sequences. KEY RESULTS: We demonstrate the SPT lineage to have arisen at the base of euphyllophytes from a clade of potentially light-regulated transcription factors through gene duplication followed by the loss of an Active Phytochrome Binding (APB) domain. We also clarify the more recent evolutionary history of SPT and its paralog ALCATRAZ (ALC), which appear to have arisen through a large-scale duplication within Brassicales. We find that SPT orthologs from diverse groups of seed plants share strikingly similar capacities for protein-protein and protein-DNA interactions, and that SPT coding regions from a wide taxonomic range of plants are able to complement loss-of-function spt mutations in transgenic Arabidopsis. However, the expression pattern of SPT appears to have evolved significantly within angiosperms, and we identify structural changes in SPT's promoter region that correlate with the acquisition of high expression levels in tissues arising from the CMM in Brassicaeae. CONCLUSIONS: We conclude that changes to SPT's expression pattern made a major contribution to the evolution of its developmental role in the gynoecium of Brassicaeae. By contrast, the main biochemical capacities of SPT, as well as many of its immediate transcriptional targets, appear to have been conserved at least since the base of living angiosperms.
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This study assesses the nutritional composition and safety of lab-produced snail flour derived from Helix aspersa aspersa, an herbivorous pulmonated gastropod mollusc that occupies various trophic levels in food chains. Our analysis focused on key nutritional aspects, including moisture, ash, protein, and fat contents. Contaminant analysis on the powder showed levels below detectable limits for PAHs, PCBs, PBDEs. The heavy metal concentration was found to be either on par with or lower than values reported in existing literature, indicating the safety of these snail powders for human consumption. Our results revealed a notable presence of polyunsaturated fatty acids and essential amino acids and strongly support the idea that snail powders can serve as sustainable protein sources in both human and animal diets.
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Helix-loop-helix (HLH) transcription factors (TFs) play a key role in various cellular differentiation and function through the regulation of enhancer activity. E2A, a member of the mammalian E-protein family (class I HLH protein), is well known to play an important role in hematopoiesis, especially in adaptive lymphocyte development. E2A instructs B- and T-cell lineage development through the regulation of enhancer activity for B- or T-cell signature gene expression, including Rag1 and Rag2 (Rag1/2) genes. In this chapter, we mainly focus on the function of E2A in B-cell development and on the roles of E2A in establishing the enhancer landscape through the recruitment of EP300/KAT3B, chromatin remodeling complex, mediator, cohesion, and TET proteins. Finally, we demonstrate how E2A orchestrates the assembly of the Rag1/2 gene super-enhancer (SE) formation by changing the chromatin conformation across the Rag gene locus.
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Linfócitos B , Proteínas de Homeodomínio , Humanos , Animais , Linfócitos B/imunologia , Linfócitos B/metabolismo , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Elementos Facilitadores Genéticos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Montagem e Desmontagem da Cromatina , Diferenciação Celular/genética , Cromatina/metabolismo , Cromatina/genética , Proteína p300 Associada a E1A/metabolismo , Proteína p300 Associada a E1A/genética , Proteínas de Ligação a DNA , Proteínas NuclearesRESUMO
The initiation of DNA replication is tightly controlled by the licensing system that loads replicative DNA helicases onto replication origins to form pre-replicative complexes (pre-RCs) once per cell cycle. Cdc10-dependent transcript 1 (Cdt1) plays an essential role in the licensing reaction by recruiting mini-chromosome maintenance (MCM) complexes, which are eukaryotic replicative DNA helicases, to their origins via direct protein-protein interactions. Cdt1 interacts with other pre-RC components, the origin recognition complex, and the cell division cycle 6 (Cdc6) protein; however, the molecular mechanism by which Cdt1 functions in the MCM complex loading process has not been fully elucidated. Here, we analyzed the protein-protein interactions of recombinant Cdt1 and observed that Cdt1 self-associates via the central region of the molecule, which is inhibited by the endogenous licensing inhibitor, geminin. Mutation of two ß-strands of the winged-helix domain in the central region of Cdt1 attenuated its self-association but could still interact with other pre-RC components and DNA similarly to wild-type Cdt1. Moreover, the Cdt1 mutant showed decreased licensing activity in Xenopus egg extracts. Together, these results suggest that the self-association of Cdt1 is crucial for licensing.
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Proteínas de Ciclo Celular , Geminina , Animais , Geminina/metabolismo , Geminina/genética , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genética , Replicação do DNA , Proteínas de Xenopus/metabolismo , Proteínas de Xenopus/genética , Xenopus laevis , Domínios Proteicos , Xenopus , Humanos , Proteínas de Ligação a DNARESUMO
Effective molecular strategies are needed to target pathogenic bacteria that thrive and proliferate within mammalian cells, a sanctuary inaccessible to many therapeutics. Herein, we present a class of cationic amphiphilic polyproline helices (CAPHs) with a rigid placement of the cationic moiety on the polyproline helix and assess the role of configuration of the unnatural proline residues making up the CAPHs. By shortening the distance between the guanidinium side chain and the proline backbone of the agents, a notable increase in cellular uptake and antibacterial activity was observed, whereas changing the configuration of the moieties on the pyrrolidine ring from cis to trans resulted in more modest increases. When the combination of these two activities was evaluated, the more rigid CAPHs were exceptionally effective at eradicating intracellular methicillin-resistant Staphylococcus aureus (MRSA) and Salmonella infections within macrophages, significantly exceeding the clearance with the parent CAPH.