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1.
IUCrJ ; 11(Pt 3): 384-394, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38656311

RESUMEN

Immunodominant membrane protein (IMP) is a prevalent membrane protein in phytoplasma and has been confirmed to be an F-actin-binding protein. However, the intricate molecular mechanisms that govern the function of IMP require further elucidation. In this study, the X-ray crystallographic structure of IMP was determined and insights into its interaction with plant actin are provided. A comparative analysis with other proteins demonstrates that IMP shares structural homology with talin rod domain-containing protein 1 (TLNRD1), which also functions as an F-actin-binding protein. Subsequent molecular-docking studies of IMP and F-actin reveal that they possess complementary surfaces, suggesting a stable interaction. The low potential energy and high confidence score of the IMP-F-actin binding model indicate stable binding. Additionally, by employing immunoprecipitation and mass spectrometry, it was discovered that IMP serves as an interaction partner for the phytoplasmal effector causing phyllody 1 (PHYL1). It was then shown that both IMP and PHYL1 are highly expressed in the S2 stage of peanut witches' broom phytoplasma-infected Catharanthus roseus. The association between IMP and PHYL1 is substantiated through in vivo immunoprecipitation, an in vitro cross-linking assay and molecular-docking analysis. Collectively, these findings expand the current understanding of IMP interactions and enhance the comprehension of the interaction of IMP with plant F-actin. They also unveil a novel interaction pathway that may influence phytoplasma pathogenicity and host plant responses related to PHYL1. This discovery could pave the way for the development of new strategies to overcome phytoplasma-related plant diseases.


Asunto(s)
Phytoplasma , Phytoplasma/química , Cristalografía por Rayos X , Proteínas de la Membrana/química , Proteínas de la Membrana/metabolismo , Proteínas Bacterianas/química , Proteínas Bacterianas/metabolismo , Actinas/metabolismo , Actinas/química , Enfermedades de las Plantas/microbiología , Catharanthus/microbiología , Catharanthus/inmunología , Simulación del Acoplamiento Molecular , Unión Proteica
2.
Sci Rep ; 14(1): 5454, 2024 03 05.
Artículo en Inglés | MEDLINE | ID: mdl-38443405

RESUMEN

It is widely believed that a significant portion of the gut microbiota, which play crucial roles in overall health and disease, originates from the food we consume. Sashimi is a type of popular raw seafood cuisine. Its microbiome, however, remained to be thoroughly explored. The objective of this study is to explore the microbiome composition in sashimi at the time when it is served and ready to be eaten. Specifically, our tasks include investigating the diversity and characteristics of microbial profiles in sashimi with respect to the fish types. We utilized the Sanger-sequencing based DNA barcoding technology for fish species authentication and next-generation sequencing for sashimi microbiome profiling. We investigated the microbiome profiles of amberjack, cobia, salmon, tuna and tilapia sashimi, which were all identified using the MT-CO1 DNA sequences regardless of their menu offering names. Chao1 and Shannon indexes, as well as Bray-Curtis dissimilarity index were used to evaluate the alpha and beta diversities of sashimi microbiome. We successfully validated our previous observation that tilapia sashimi has a significantly higher proportions of Pseudomonas compared to other fish sashimi, using independent samples (P = 0.0010). Salmon sashimi exhibited a notably higher Chao1 index in its microbiome in contrast to other fish species (P = 0.0031), indicating a richer and more diverse microbial ecosystem. Non-Metric Multidimensional Scaling (NMDS) based on Bray-Curtis dissimilarity index revealed distinct clusters of microbiome profiles with respect to fish types. Microbiome similarity was notably observed between amberjack and tuna, as well as cobia and salmon. The relationship of microbiome similarity can be depicted as a tree which resembles partly the phylogenetic tree of host species, emphasizing the close relationship between host evolution and microbial composition. Moreover, salmon exhibited a pronounced relative abundance of the Photobacterium genus, significantly surpassing tuna (P = 0.0079), observed consistently across various restaurant sources. In conclusion, microbiome composition of Pseudomonas is significantly higher in tilapia sashimi than in other fish sashimi. Salmon sashimi has the highest diversity of microbiome among all fish sashimi that we analyzed. The level of Photobacterium is significantly higher in salmon than in tuna across all the restaurants we surveyed. These findings provide critical insights into the intricate relationship between the host evolution and the microbial composition. These discoveries deepen our understanding of sashimi microbiota, facilitating our decision in selecting raw seafood.


Asunto(s)
Microbioma Gastrointestinal , Microbiota , Animales , Filogenia , Microbiota/genética , Microbioma Gastrointestinal/genética , Salmón , Atún/genética , Alimentos Marinos , Photobacterium , Pseudomonas
3.
J Chin Med Assoc ; 87(2): 139-141, 2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-38305483

RESUMEN

The coronavirus disease 2019 (COVID-19) pandemic has had a major impact on human life. This review highlights the versatile roles of both classical and modern structure-based approaches for COVID-19. X-ray crystallography, nuclear magnetic resonance spectroscopy, and cryogenic electron microscopy are the three cornerstones of classical structural biology. These technologies have helped provide fundamental and detailed knowledge regarding severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the related human host proteins as well as enabled the identification of its target sites, facilitating the cessation of its transmission. Further progress into protein structure modeling was made using modern structure-based approaches derived from homology modeling and integrated with artificial intelligence (AI), facilitating advanced computational simulation tools to actively guide the design of new vaccines and the development of anti-SARS-CoV-2 drugs. This review presents the practical contributions and future directions of structure-based approaches for COVID-19.


Asunto(s)
COVID-19 , Humanos , SARS-CoV-2 , Inteligencia Artificial , Vacunas contra la COVID-19 , Simulación por Computador
4.
Nat Commun ; 14(1): 5464, 2023 09 06.
Artículo en Inglés | MEDLINE | ID: mdl-37673860

RESUMEN

The abuse of antibiotics has led to the emergence of multidrug-resistant microbial pathogens, presenting a pressing challenge in global healthcare. Membrane-disrupting antimicrobial peptides (AMPs) combat so-called superbugs via mechanisms different than conventional antibiotics and have good application prospects in medicine, agriculture, and the food industry. However, the mechanism-of-action of AMPs has not been fully characterized at the cellular level due to a lack of high-resolution imaging technologies that can capture cellular-membrane disruption events in the hydrated state. Previously, we reported PepD2M, a de novo-designed AMP with potent and wide-spectrum bactericidal and fungicidal activity. In this study, we use cryo-electron tomography (cryo-ET) and high-speed atomic force microscopy (HS-AFM) to directly visualize the pepD2M-induced disruption of the outer and inner membranes of the Gram-negative bacterium Escherichia coli, and compared with a well-known pore-forming peptide, melittin. Our high-resolution cryo-ET images reveal how pepD2M disrupts the E. coli membrane using a carpet/detergent-like mechanism. Our studies reveal the direct membrane-disrupting consequence of AMPs on the bacterial membrane by cryo-ET, and this information provides critical insights into the mechanisms of this class of antimicrobial agents.


Asunto(s)
Péptidos Antimicrobianos , Tomografía con Microscopio Electrónico , Escherichia coli , Fenómenos Fisiológicos Celulares , Antibacterianos/farmacología
5.
J Chin Med Assoc ; 86(2): 138-146, 2023 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-36227021

RESUMEN

COVID-19 has greatly affected human life for over 3 years. In this review, we focus on smart healthcare solutions that address major requirements for coping with the COVID-19 pandemic, including (1) the continuous monitoring of severe acute respiratory syndrome coronavirus 2, (2) patient stratification with distinct short-term outcomes (eg, mild or severe diseases) and long-term outcomes (eg, long COVID), and (3) adherence to medication and treatments for patients with COVID-19. Smart healthcare often utilizes medical artificial intelligence (AI) and cloud computing and integrates cutting-edge biological and optoelectronic techniques. These are valuable technologies for addressing the unmet needs in the management of COVID. By leveraging deep learning/machine learning capabilities and big data, medical AI can perform precise prognosis predictions and provide reliable suggestions for physicians' decision-making. Through the assistance of the Internet of Medical Things, which encompasses wearable devices, smartphone apps, internet-based drug delivery systems, and telemedicine technologies, the status of mild cases can be continuously monitored and medications provided at home without the need for hospital care. In cases that develop into severe cases, emergency feedback can be provided through the hospital for rapid treatment. Smart healthcare can possibly prevent the development of severe COVID-19 cases and therefore lower the burden on intensive care units.


Asunto(s)
COVID-19 , Humanos , Inteligencia Artificial , Síndrome Post Agudo de COVID-19 , Pandemias/prevención & control , Atención a la Salud
6.
J Chin Med Assoc ; 85(9): 891-895, 2022 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-35816282

RESUMEN

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its variants of concern can infect people of all ages and can cause severe diseases in children, such as encephalitis, which require intensive care. Therefore, vaccines are urgently required to prevent severe disease in all age groups. We reviewed the safety and efficacy profiles of mRNA vaccines-BNT162b2 and mRNA-1273-demonstrated by clinical trials or observed in the real world. mRNA-1273 is effective in preventing SARS-CoV-2 infection in preschool children (6 months-6 years old). Both BNT162b2 and mRNA-1273 are effective in preventing SARS-CoV-2 infection in school-aged children and adolescents, thereby preventing post-coronavirus disease (COVID) conditions. The common side effects of vaccination are pain at the injection site, fatigue, and headache. Myocarditis and pericarditis are uncommon. Monitoring post-vaccination troponin levels may help prevent severe cardiac events. The SARS-CoV-2 coronavirus mutates its genome to overcome the herd immunity provided by mass vaccinations; therefore, we may need to develop new generations of vaccines, such as those using viral nucleocapsid proteins as antigens. In conclusion, the mRNA vaccines are generally safe and effective in preventing severe diseases and hospitalization among children and adolescents.


Asunto(s)
Vacunas contra la COVID-19 , COVID-19 , Adolescente , Vacuna BNT162 , COVID-19/prevención & control , Vacunas contra la COVID-19/efectos adversos , Niño , Preescolar , Hospitalización , Humanos , Proteínas de la Nucleocápside , SARS-CoV-2 , Troponina , Vacunación , Vacunas Virales
7.
Sci Rep ; 11(1): 23282, 2021 12 02.
Artículo en Inglés | MEDLINE | ID: mdl-34857809

RESUMEN

Medulloblastoma is the most common embryonic brain tumor in children. We investigated a cohort of 52 Asian medulloblastoma patients aged between 0 and 19 years old, who received surgical resections and post-resection treatments in the Taipei Medical University Hospital and the Taipei Veterans General Hospital. Genome-wide RNA sequencing was performed on fresh-frozen surgical tissues. These data were analyzed using the CIBERSORTx immune deconvolution software. Two external clinical and molecular datasets from United States (n = 62) and Canada (n = 763) were used to evaluate the transferability of the gene-signature scores across ethnic populations. The abundance of 13 genes, including DLL1, are significantly associated with overall survival (All Cox regression P < 0.001). A gene-signature score was derived from the deep transcriptome, capable of indicating patients' subsequent tumor recurrence (Hazard Ratio [HR] 1.645, confidence interval [CI] 1.337-2.025, P < 0.001) and mortality (HR 2.720, CI 1.798-4.112, P < 0.001). After the adjustment of baseline clinical factors, the score remains indicative of recurrence-free survival (HR 1.604, CI 1.292-1.992, P < 0.001) and overall survival (HR 2.781, CI 1.762-4.390, P < 0.001). Patients stratified by this score manifest not only distinct prognosis but also different molecular characteristics: Notch signaling ligands and receptors are comparatively overexpressed in patients with poorer prognosis, while tumor infiltrating natural killer cells are more abundant in patients with better prognosis. Additionally, immunohistochemical staining showed the DLL1 protein, a major ligand in the Notch signaling pathway, and the NCAM1 protein, a representative biomarker of natural killer cells, are present in the surgical tissues of patients of four molecular subgroups, WNT, SHH, Group 3 and Group 4. NCAM1 RNA level is also positively associated with the mutation burden in tumor (P = 0.023). The gene-signature score is validated successfully in the Canadian cohort (P = 0.009) as well as its three molecular subgroups (SHH, Group 3 and Group 4; P = 0.047, 0.018 and 0.040 respectively). In conclusion, pediatric medullablastoma patients can be stratified by gene-signature scores with distinct prognosis and molecular characteristics. Ligands and receptors of the Notch signaling pathway are overexpressed in the patient stratum with poorer prognosis. Tumor infiltrating natural killer cells are more abundant in the patient stratum with better prognosis.


Asunto(s)
Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patología , Regulación Neoplásica de la Expresión Génica/genética , Expresión Génica , Células Asesinas Naturales/patología , Linfocitos Infiltrantes de Tumor/patología , Meduloblastoma/genética , Meduloblastoma/patología , Receptores Notch/genética , Receptores Notch/metabolismo , Transducción de Señal/genética , Transducción de Señal/fisiología , Adolescente , Factores de Edad , Neoplasias Encefálicas/cirugía , Antígeno CD56/genética , Antígeno CD56/metabolismo , Proteínas de Unión al Calcio/genética , Proteínas de Unión al Calcio/metabolismo , Niño , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Meduloblastoma/cirugía , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Pronóstico , Análisis de Secuencia de ARN/métodos , Taiwán , Adulto Joven
8.
Int J Biol Macromol ; 160: 903-914, 2020 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-32502608

RESUMEN

Uracil-DNA glycosylases (UDGs) are conserved DNA-repair enzymes that can be found in many species, including herpesviruses. Since they play crucial roles for efficient viral DNA replication in herpesviruses, they have been considered as potential antiviral targets. In our previous work, Staphylococcus aureus SAUGI was identified as a DNA mimic protein that targets UDGs from S. aureus, human, Herpes simplex virus (HSV) and Epstein-Barr virus (EBV). Interestingly, SAUGI has the strongest inhibitory effects with EBVUDG. Here, we determined complex structures of SAUGI with EBVUDG and another γ-herpesvirus UDG from Kaposi's sarcoma-associated herpesvirus (KSHVUDG), which SAUGI fails to effectively inhibit. Structural analysis of the SAUGI/EBVUDG complex suggests that the additional interaction between SAUGI and the leucine loop may explain why SAUGI shows the highest binding capacity with EBVUDG. In contrast, SAUGI appears to make only partial contacts with the key components responsible for the compression and stabilization of the DNA backbone in the leucine loop extension of KSHVUDG. The findings in this study provide a molecular explanation for the differential inhibitory effects and binding strengths that SAUGI has on these two UDGs, and the structural basis of the differences should be helpful in developing inhibitors that would interfere with viral DNA replication.


Asunto(s)
Enzimas Reparadoras del ADN/química , Gammaherpesvirinae/enzimología , Uracil-ADN Glicosidasa/química , Sustitución de Aminoácidos , Enzimas Reparadoras del ADN/aislamiento & purificación , Enzimas Reparadoras del ADN/metabolismo , Replicación del ADN , Modelos Moleculares , Conformación Molecular , Unión Proteica , Proteínas Recombinantes , Relación Estructura-Actividad , Uracil-ADN Glicosidasa/aislamiento & purificación , Uracil-ADN Glicosidasa/metabolismo
9.
Plant J ; 100(4): 706-719, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31323156

RESUMEN

Phytoplasmas are bacterial plant pathogens which can induce severe symptoms including dwarfism, phyllody and virescence in an infected plant. Because phytoplasmas infect many important crops such as peanut and papaya they have caused serious agricultural losses. The phytoplasmal effector causing phyllody 1 (PHYL1) is an important phytoplasmal pathogenic factor which affects the biological function of MADS transcription factors by interacting with their K (keratin-like) domain, thus resulting in abnormal plant developments such as phyllody. Until now, lack of information on the structure of PHYL1 has prevented a detailed understanding of the binding mechanism between PHYL1 and the MADS transcription factors. Here, we present the crystal structure of PHYL1 from peanut witches'-broom phytoplasma (PHYL1PnWB ). This protein was found to fold into a unique α-helical hairpin with exposed hydrophobic residues on its surface that may play an important role in its biological function. Using proteomics approaches, we propose a binding mode of PHYL1PnWB with the K domain of the MADS transcription factor SEPALLATA3 (SEP3_K) and identify the residues of PHYL1PnWB that are important for this interaction. Furthermore, using surface plasmon resonance we measure the binding strength of PHYL1PnWB proteins to SEP3_K. Lastly, based on confocal images, we found that α-helix 2 of PHYL1PnWB plays an important role in PHYL1-mediated degradation of SEP3. Taken together, these results provide a structural understanding of the specific binding mechanism between PHYL1PnWB and SEP3_K.


Asunto(s)
Proteínas Bacterianas/química , Proteínas de Dominio MADS/metabolismo , Phytoplasma/química , Proteínas de Plantas/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Reactivos de Enlaces Cruzados/química , Cristalografía por Rayos X , Interacciones Huésped-Patógeno/fisiología , Interacciones Hidrofóbicas e Hidrofílicas , Proteínas de Dominio MADS/química , Proteínas de Dominio MADS/genética , Complejos Multiproteicos/química , Mutación , Phytoplasma/patogenicidad , Enfermedades de las Plantas/microbiología , Proteínas de Plantas/química , Proteínas de Plantas/genética , Dominios y Motivos de Interacción de Proteínas
10.
PLoS Pathog ; 15(6): e1007826, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-31220181

RESUMEN

Vaccinia mature virus requires A26 envelope protein to mediate acid-dependent endocytosis into HeLa cells in which we hypothesized that A26 protein functions as an acid-sensitive membrane fusion suppressor. Here, we provide evidence showing that N-terminal domain (aa1-75) of A26 protein is an acid-sensitive region that regulates membrane fusion. Crystal structure of A26 protein revealed that His48 and His53 are in close contact with Lys47, Arg57, His314 and Arg312, suggesting that at low pH these His-cation pairs could initiate conformational changes through protonation of His48 and His53 and subsequent electrostatic repulsion. All the A26 mutant mature viruses that interrupted His-cation pair interactions of His48 and His 53 indeed have lost virion infectivity. Isolation of revertant viruses revealed that second site mutations caused frame shifts and premature termination of A26 protein such that reverent viruses regained cell entry through plasma membrane fusion. Together, we conclude that viral A26 protein functions as an acid-sensitive fusion suppressor during vaccinia mature virus endocytosis.


Asunto(s)
Endocitosis , Fusión de Membrana , Virus Vaccinia/metabolismo , Proteínas Virales/metabolismo , Internalización del Virus , Animales , Chlorocebus aethiops , Células HeLa , Humanos , Concentración de Iones de Hidrógeno , Ratones , Virus Vaccinia/genética , Proteínas Virales/genética
11.
PLoS One ; 12(12): e0189461, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29220372

RESUMEN

DNA mimicry is a direct and effective strategy by which the mimic competes with DNA for the DNA binding sites on other proteins. Until now, only about a dozen proteins have been shown to function via this strategy, including the DNA mimic protein DMP19 from Neisseria meningitides. We have shown previously that DMP19 dimer prevents the operator DNA from binding to the transcription factor NHTF. Here, we provide new evidence that DMP19 monomer can also interact with the Neisseria nucleoid-associated protein HU. Using BS3 crosslinking, gel filtration and isothermal titration calorimetry assays, we found that DMP19 uses its monomeric form to interact with the Neisseria HU dimer. Crosslinking conjugated mass spectrometry was used to investigate the binding mode of DMP19 monomer and HU dimer. Finally, an electrophoretic mobility shift assay (EMSA) confirmed that the DNA binding affinity of HU is affected by DMP19. These results showed that DMP19 is bifunctional in the gene regulation of Neisseria through its variable oligomeric forms.


Asunto(s)
Proteínas Bacterianas/metabolismo , Histonas/metabolismo , Imitación Molecular , Neisseria/metabolismo , Proteínas Bacterianas/genética , Dimerización , Unión Proteica
12.
Proc Natl Acad Sci U S A ; 114(10): 2479-2484, 2017 03 07.
Artículo en Inglés | MEDLINE | ID: mdl-28228526

RESUMEN

We report experimental and computational studies investigating the effects of three osmolytes, trimethylamine N-oxide (TMAO), betaine, and glycine, on the hydrophobic collapse of an elastin-like polypeptide (ELP). All three osmolytes stabilize collapsed conformations of the ELP and reduce the lower critical solution temperature (LSCT) linearly with osmolyte concentration. As expected from conventional preferential solvation arguments, betaine and glycine both increase the surface tension at the air-water interface. TMAO, however, reduces the surface tension. Atomically detailed molecular dynamics (MD) simulations suggest that TMAO also slightly accumulates at the polymer-water interface, whereas glycine and betaine are strongly depleted. To investigate alternative mechanisms for osmolyte effects, we performed FTIR experiments that characterized the impact of each cosolvent on the bulk water structure. These experiments showed that TMAO red-shifts the OH stretch of the IR spectrum via a mechanism that was very sensitive to the protonation state of the NO moiety. Glycine also caused a red shift in the OH stretch region, whereas betaine minimally impacted this region. Thus, the effects of osmolytes on the OH spectrum appear uncorrelated with their effects upon hydrophobic collapse. Similarly, MD simulations suggested that TMAO disrupts the water structure to the least extent, whereas glycine exerts the greatest influence on the water structure. These results suggest that TMAO stabilizes collapsed conformations via a mechanism that is distinct from glycine and betaine. In particular, we propose that TMAO stabilizes proteins by acting as a surfactant for the heterogeneous surfaces of folded proteins.


Asunto(s)
Betaína/química , Elastina/química , Glicina/química , Metilaminas/química , Péptidos/química , Aire/análisis , Interacciones Hidrofóbicas e Hidrofílicas , Simulación de Dinámica Molecular , Presión Osmótica , Pliegue de Proteína , Soluciones , Tensión Superficial , Agua/química
13.
Acta Crystallogr D Biol Crystallogr ; 68(Pt 10): 1380-92, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22993092

RESUMEN

Cyclic di-GMP (c-di-GMP) is a novel secondary-messenger molecule that is involved in regulating a plethora of important bacterial activities through binding to an unprecedented array of effectors. Proteins with a canonical PilZ domain that bind c-di-GMP play crucial roles in regulating flagellum-based motility. In contrast, noncanonical type II PilZ domains that do not effectively bind c-di-GMP regulate twitching motility, which is dependent on type IV pili (T4P). Recent data indicate that T4P biogenesis is initiated via the interaction of a noncanonical type II PilZ protein with the GGDEF/EAL-domain protein FimX and the pilus motor protein PilB at high c-di-GMP concentrations. However, the molecular details of such interactions remain to be elucidated. In this manuscript, the first hetero-complex crystal structure between a type II PilZ protein and the EAL domain of the FimX protein (FimX(EAL)) from Xanthomonas campestris pv. campestris (Xcc) in the presence of c-di-GMP is reported. This work reveals two novel conformations of monomeric c-di-GMP in the XccFimX(EAL)-c-di-GMP and XccFimX(EAL)-c-di-GMP-XccPilZ complexes, as well as a unique interaction mode of a type II PilZ domain with FimX(EAL). These findings indicate that c-di-GMP is sufficiently flexible to adjust its conformation to match the corresponding recognition motifs of different cognate effectors. Together, these results represent a first step towards an understanding of how T4P biogenesis is controlled by c-di-GMP at the molecular level and also of the ability of c-di-GMP to bind to a wide variety of effectors.


Asunto(s)
Proteínas Bacterianas/química , GMP Cíclico/análogos & derivados , Xanthomonas campestris/química , Proteínas Bacterianas/clasificación , Proteínas Bacterianas/metabolismo , Cristalografía por Rayos X , GMP Cíclico/química , GMP Cíclico/metabolismo , Unión Proteica , Estructura Terciaria de Proteína , Pseudomonas aeruginosa/química , Homología de Secuencia de Aminoácido
14.
Artículo en Inglés | MEDLINE | ID: mdl-22442228

RESUMEN

c-di-GMP is a major secondary-messenger molecule in regulation of bacterial pathogenesis. Therefore, the c-di-GMP-mediated signal transduction network is of considerable interest. The PilZ domain was the first c-di-GMP receptor to be predicted and identified. However, every PilZ domain binds c-di-GMP with a different binding affinity. Intriguingly, a noncanonical PilZ domain has recently been found to serve as a mediator to link FimX(EAL) to the PilB or PilT ATPase to control the function of type IV pili (T4P). It is thus essential to determine the structure of the FimX(EAL)-PilZ complex in order to determine how the binding of c-di-GMP to the FimX(EAL) domain induces conformational change of the adjoining noncanonical PilZ domain, which may transmit information to PilB or PilT to control T4P function. Here, the preparation and preliminary X-ray diffraction studies of the XccFimX(EAL)-c-di-GMP and XccFimX(EAL)-c-di-GMP-XccPilZ complexes from Xcc (Xanthomonas campestris pv. campesteris) are reported. Detailed studies of these complexes may allow a more thorough understanding of how c-di-GMP transmits its effects through the degenerate EAL domain and the noncanonical PilZ domain.


Asunto(s)
Proteínas Bacterianas/química , GMP Cíclico/análogos & derivados , Xanthomonas campestris/química , Cristalización , Cristalografía por Rayos X , GMP Cíclico/química , GMP Cíclico/metabolismo , Unión Proteica
15.
Kaohsiung J Med Sci ; 28(2): 105-10, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22313538

RESUMEN

In 2009, Typhoon Morakot struck Taiwan and caused serious harm to the indigenous peoples living in the southern mountainous regions. The objective of this study is to examine the effects of and the factors involved in individual resilience intervention of typhoon victims. Quantitative research was performed from October 2009 through September 2010. Purposive sampling yielded 77 indigenous persons who were willing to serve as participants in this study. These participants all maintained legal or actual residence in the areas of Kaohsiung that were affected by the typhoon. An individual resilience intervention program was implemented. The findings show the following: (1) after completing the individual resilience intervention program, the participants had higher individual resilience scores than before participating in the intervention program; and (2) individual resilience scores were significantly affected by residency after the typhoon. These findings suggest that an individual resilience intervention program is a useful approach that can be used to enhance the individual resilience of a victim and that professionals should pay more attention to victims who have to leave their hometowns after disasters.


Asunto(s)
Tormentas Ciclónicas , Trastornos por Estrés Postraumático/fisiopatología , Adolescente , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Taiwán , Adulto Joven
16.
J Asian Nat Prod Res ; 13(4): 284-9, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21462030

RESUMEN

Pueraria lobata flower is a medicinal herb for treating intoxication, hepatic, and gastrointestinal tract lesions induced by alcohol. This study aims to investigate the isoflavonoid glycosides in P. lobata flowers. Two new isoflavone compounds were isolated from the extract of P. lobata flowers. Their structures were determined to be 5,6,7,4'-tetrahydroxyisoflavone-6,7-di-O-ß-D-glucopyranoside and 5,6,7-trihydroxy-4'-methoxyisoflavone-6,7-di-O-ß-D-glucopyranoside on the basis of spectroscopic means including HR-ESI-MS, UV, IR, ¹H, and ¹³C NMR.


Asunto(s)
Medicamentos Herbarios Chinos/química , Glicósidos/aislamiento & purificación , Isoflavonas/aislamiento & purificación , Pueraria/química , Flores/química , Glicósidos/química , Isoflavonas/química , Estructura Molecular , Resonancia Magnética Nuclear Biomolecular , Estereoisomerismo
17.
Eur J Pharmacol ; 560(2-3): 101-9, 2007 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-17307160

RESUMEN

A previous report showed that transforming growth factor-beta1 (TGF-beta1) can induce heme oxygenase-1 (HO-1) expression, attenuate cellular injury, and maintain tissue homeostasis. In this study, we investigated the involvement of phosphoinositide-3-OH-kinase (PI3K)/Akt and the nuclear factor-kappaB (NF-kappaB) signaling pathway in TGF-beta1-induced HO-1 expression in human lung epithelial cells (A549). Treatment of A549 cells with TGF-beta1 caused HO-1 to be expressed in a concentration- and time-dependent manner. Treatment of A549 cells with LY 294002 (2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one, a PI3K inhibitor), an Akt inhibitor, and the dominant negative mutant of Akt (Akt DN) inhibited TGF-beta1-induced HO-1 expression and HO-1-luciferase activity. Stimulation of cells with TGF-beta1 caused an increase in Akt phosphorylation in a time-dependent manner, which was inhibited by wortmannin and LY 294002 (PI3K inhibitors). In addition, treatment of A549 cells with Bay 117082 ((E)-3-[4-methylphenylsulfonyl]-2-propenenitrile, an IkappaB phosphorylation inhibitor), pyrrolidine dithiocarbamate (PDTC, an NF-kappaB inhibitor), and the dominant negative mutant of IkappaBalpha (IkappaBalphaM) inhibited TGF-beta1-induced HO-1 expression and HO-1-luciferase activity. Treatment of A549 cells with TGF-beta1-induced IkappaB kinase alpha/beta (IKKalpha/beta) phosphorylation, IkappaBalpha phosphorylation, IkappaBalpha degradation, p65 Ser536 phosphorylation, and kappaB-luciferase activity. The TGF-beta1-mediated increases in IKKalpha/beta phosphorylation, p65 Ser536 phosphorylation, and kappaB-luciferase activity were inhibited by LY 294002, an Akt inhibitor, and Akt DN. Taken together, these results suggest that the PI3K/Akt dependent IKKalpha/beta/NF-kappaB signaling pathway plays an important role in TGF-beta1-induced HO-1 expression in A549 cells.


Asunto(s)
Hemo-Oxigenasa 1/análisis , Pulmón/efectos de los fármacos , FN-kappa B/fisiología , Fosfatidilinositol 3-Quinasas/fisiología , Proteínas Proto-Oncogénicas c-akt/fisiología , Transducción de Señal/fisiología , Factor de Crecimiento Transformador beta1/farmacología , Células Cultivadas , Células Epiteliales/efectos de los fármacos , Células Epiteliales/enzimología , Hemo-Oxigenasa 1/biosíntesis , Humanos , Proteínas I-kappa B/metabolismo , Pulmón/enzimología , Inhibidor NF-kappaB alfa , Fosforilación , Factor de Transcripción ReIA/metabolismo
18.
J Immunol ; 177(1): 681-93, 2006 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-16785567

RESUMEN

In this study, we investigated the signaling pathway involved in IL-6 production caused by peptidoglycan (PGN), a cell wall component of the Gram-positive bacterium, Staphylococcus aureus, in RAW 264.7 macrophages. PGN caused concentration- and time-dependent increases in IL-6, PGE(2), and cAMP production. PGN-mediated IL-6 production was inhibited by a nonselective cyclooxygenase (COX) inhibitor (indomethacin), a selective COX-2 inhibitor (NS398), a PGE(2) (EP2) antagonist (AH6809), a PGE(4) (EP4) antagonist (AH23848), and a protein kinase A (PKA) inhibitor (KT5720), but not by a nonselective NO synthase inhibitor (N(G)-nitro-l-arginine methyl ester). Furthermore, PGE(2), an EP2 agonist (butaprost), an EP2/PGE(3) (EP3)/EP4 agonist (misoprostol), and misoprostol in the presence of AH6809 all induced IL-6 production, whereas an EP1/EP3 agonist (sulprostone) did not. PGN caused time-dependent activations of IkappaB kinase alphabeta (IKKdbeta) and p65 phosphorylation at Ser(276), and these effects were inhibited by NS398 and KT5720. Both PGE(2) and 8-bromo-cAMP also caused IKKdbeta kinase alphabeta phosphorylation. PGN resulted in two waves of the formation of NF-kappaB-specific DNA-protein complexes. The first wave of NF-kappaB activation occurred at 10-60 min of treatment, whereas the later wave occurred at 2-12 h of treatment. The PGN-induced increase in kappaB luciferase activity was inhibited by NS398, AH6809, AH23848, KT5720, a protein kinase C inhibitor (Ro31-8220), and a p38 MAPK inhibitor (SB203580). These results suggest that PGN-induced IL-6 production involves COX-2-generated PGE(2), activation of the EP2 and EP4 receptors, cAMP formation, and the activation of PKA, protein kinase C, p38 MAPK, IKKdbeta, kinase alphabeta, p65 phosphorylation, and NF-kappaB. However, PGN-induced NO release is not involved in the signaling pathway of PGN-induced IL-6 production.


Asunto(s)
Proteínas Quinasas Dependientes de AMP Cíclico/fisiología , Ciclooxigenasa 2/fisiología , Quinasa I-kappa B/fisiología , Interleucina-6/biosíntesis , Macrófagos/inmunología , FN-kappa B/fisiología , Peptidoglicano/farmacología , Receptores de Prostaglandina E/fisiología , Animales , Línea Celular , AMP Cíclico/biosíntesis , AMP Cíclico/fisiología , Proteínas Quinasas Dependientes de AMP Cíclico/antagonistas & inhibidores , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Ciclooxigenasa 2/metabolismo , Inhibidores de la Ciclooxigenasa 2/farmacología , Dinoprostona/antagonistas & inhibidores , Dinoprostona/biosíntesis , Dinoprostona/metabolismo , Dinoprostona/fisiología , Activación Enzimática/efectos de los fármacos , Activación Enzimática/inmunología , Quinasa I-kappa B/antagonistas & inhibidores , Quinasa I-kappa B/metabolismo , Macrófagos/enzimología , Macrófagos/metabolismo , Macrófagos/microbiología , Ratones , FN-kappa B/antagonistas & inhibidores , FN-kappa B/metabolismo , Fosforilación , Receptores de Prostaglandina E/antagonistas & inhibidores , Subtipo EP4 de Receptores de Prostaglandina E , Serina/metabolismo , Transducción de Señal/efectos de los fármacos , Transducción de Señal/inmunología , Staphylococcus aureus/inmunología , Factor de Transcripción ReIA/antagonistas & inhibidores , Factor de Transcripción ReIA/metabolismo
19.
Conf Proc IEEE Eng Med Biol Soc ; 2004: 3313-5, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-17270990

RESUMEN

Diabetes mellitus is a common and precarious chronic disease, which affects cellular metabolism and energy production. The condition is divided into types I and II; the most common form is type II diabetes, which is an adult-onset disease. Blood glucose testing is crucial to diabetes control, and it is effective in reducing the risk of complications and improving life quality. Unfortunately, both elderly patients and their caregivers find it difficult to monitor glucose levels long term. This study developed a communication platform for diabetes surveillance. The developed system prompts diabetics to measure their blood glucose regularly at home, and provides remote care persons with complete information about the patient's measurement. This aids in the improvement in diabetes control, thereby increasing the social activities and life quality of diabetics.

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