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1.
New Phytol ; 242(3): 909-915, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38477037

RESUMEN

Phytochrome B (phyB) is a red and far-red photoreceptor that promotes light responses. Upon photoactivation, phyB enters the nucleus and forms a molecular condensate called a photobody through liquid-liquid phase separation. Phytochrome B photobody comprises phyB, the main scaffold molecule, and at least 37 client proteins. These clients belong to diverse functional categories enriched with transcription regulators, encompassing both positive and negative light signaling factors, with the functional bias toward the negative factors. The functionally diverse clients suggest that phyB photobody acts either as a trap to capture proteins, including negatively acting transcription regulators, for processes such as sequestration, modification, or degradation or as a hub where proteins are brought into close proximity for interaction in a light-dependent manner.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Fitocromo , Humanos , Fitocromo B/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Luz , Células Fotorreceptoras/metabolismo , Fitocromo/metabolismo
2.
Comput Inform Nurs ; 41(5): 309-315, 2023 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-35551144

RESUMEN

Innovative teaching and learning strategies in pediatric clinical education are needed to ensure that learning outcomes are achieved efficiently and to improve students' satisfaction with the learning process. We developed a mobile application to enhance the clinical learning of nursing students during pediatric clinical practice and explored the participants' perceptions of the learning method. A mixed-method design and an online survey were used to assess participants' perceived achievement of learning objectives and satisfaction with the clinical practicum. Focus groups explored the participants' experience of using the application. The overall achievement of learning outcomes was 4.1 out of 5, and participants reported high satisfaction with the clinical practicum using the mobile application. Qualitative analysis of the transcripts revealed four major themes: (1) facilitation of collaborative learning through real-time interactions and communication; (2) engagement in active learning through an application; (3) a useful tool for enhancing critical thinking; and (4) the "curate's egg" nature of the application. The mobile application can be incorporated into the clinical education of nursing students to promote self-regulated learning and collaboration with faculty. Clear guidance on how to use the application in a clinical environment should be provided to students and preceptors to achieve better learning outcomes.


Asunto(s)
Bachillerato en Enfermería , Prácticas Interdisciplinarias , Aplicaciones Móviles , Estudiantes de Enfermería , Humanos , Niño , Bachillerato en Enfermería/métodos , Aprendizaje Basado en Problemas
3.
Biochem Biophys Res Commun ; 571: 125-130, 2021 09 24.
Artículo en Inglés | MEDLINE | ID: mdl-34325127

RESUMEN

This study investigated the properties of Latilactobacillus curvatus MS2 isolated from Korean traditional fermented seafood as probiotics and the effect of reducing cholesterol as a synbiotic with isomalto-oligosaccharide (IMO) in BALB/c mice. The isolated strain showed high resistance to acids and bile acids and exhibited a high DPPH scavenging capacity of 72.27 ± 0.38 %. In the intestinal adhesion test using HT-29 cells, the adhesion rate of MS2 was 17.10 ± 1.78 %, which was higher than the adhesion rate of the other investigated probiotics. MS2 showed good antimicrobial activity against food-borne pathogens, especially Staphylococcus aureus, S. epidermidis, Escherichia coli, and Vibrio vulnificus. This strain had high availability for IMO among the prebiotics of fructo-oligosaccharide, inulin and IMO. Oral administration of MS2 and IMO to BALB/c mice for 5 weeks resulted in a significant reduction in blood cholesterol levels by regulating liver lipid metabolism. These results suggest that the combination of MS2 and IMO has potential for application in functional foods.


Asunto(s)
Colesterol/metabolismo , Fermentación , Lactobacillaceae/aislamiento & purificación , Oligosacáridos/metabolismo , Prebióticos/microbiología , Alimentos Marinos/microbiología , Animales , Masculino , Ratones , Ratones Endogámicos BALB C , República de Corea , Simbióticos
4.
J Korean Med Sci ; 36(50): e346, 2021 Dec 27.
Artículo en Inglés | MEDLINE | ID: mdl-34962117

RESUMEN

In November 2021, 14 international travel-related severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) B.1.1.529 (omicron) variant of concern (VOC) patients were detected in South Korea. Epidemiologic investigation revealed community transmission of the omicron VOC. A total of 80 SARS-CoV-2 omicron VOC-positive patients were identified until December 10, 2021 and 66 of them reported no relation to the international travel. There may be more transmissions with this VOC in Korea than reported.


Asunto(s)
COVID-19/transmisión , SARS-CoV-2 , Enfermedad Relacionada con los Viajes , Adulto , Anciano , Anciano de 80 o más Años , COVID-19/epidemiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , República de Corea/epidemiología , Adulto Joven
5.
Int J Mol Sci ; 21(11)2020 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-32485896

RESUMEN

Maternal genes are important in directing early development and determining egg quality in fish. We here report the de novo transcriptome from four tissue libraries of the cyprinid loach, Misgurnus anguillicaudatus, and for the first time identified maternal gene transcripts in unfertilized eggs and suggest their immune system involvement. Expression profiles and functional enrichment revealed a total 24,116 transcripts were expressed as maternal transcripts in unfertilized eggs, which were involved in a wide range of biological functions and pathways. Comparison expression profiles and analysis of tissue specificity revealed that the large numbers of maternal transcripts were stored in unfertilized eggs near the late phase of ovarian maturation and before ovulation. Functional classification showed a total of 279 maternal immune-related transcripts classified with immune system process GO term and immune system KEGG pathway. qPCR analysis showed that transcript levels of identified maternal immune-related candidate genes were dynamically modulated during development and early ontogeny of M. anguillicaudatus. Taken together, this study could not only provide knowledge on the protective roles of maternal immune-related genes during early life stage of M. anguillicaudatus but could also be a valuable transcriptomic/genomic resource for further analysis of maternally provisioned genes in M. anguillicaudatus and other related teleost fishes.


Asunto(s)
Cipriniformes/genética , Oocitos/metabolismo , Transcriptoma , Animales , Quimiocinas/genética , Quimiocinas/metabolismo , Cipriniformes/inmunología , Femenino , Proteínas de Peces/genética , Proteínas de Peces/metabolismo , Masculino , Herencia Materna , Fagocitosis/genética
6.
J Nurs Manag ; 28(8): 2118-2127, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32166797

RESUMEN

AIM: To examine the associations between compassion competence and missed nursing care, professional quality of life and quality of life among clinical nurses. BACKGROUND: Compassionate care has been demonstrated to have a positive impact on outcomes for patients, employees and organisations. However, little is known about the associations between compassion competence and missed nursing care, professional quality of life and quality of life among clinical nurses. METHODS: A survey was conducted with 1,556 Korean clinical nurses. The associations between compassion competence and missed nursing care, professional quality of life and quality of life were examined using multivariate linear regression. RESULTS: Compassion competence was negatively associated with missed nursing care and burnout but positively associated with compassion satisfaction, secondary traumatic stress and quality of life. CONCLUSIONS: Our results extend the literature on the significant influence of compassionate care by providing evidence of its positive effects on missed nursing care, compassion satisfaction, burnout and quality of life in clinical nurses. IMPLICATIONS FOR NURSING MANAGEMENT: Nursing managers should implement programmes to improve compassion competence in clinical nurses to address missed nursing care and burnout and improve compassion satisfaction and quality of life, thus improving quality of care, patient experience and patient safety.


Asunto(s)
Agotamiento Profesional , Desgaste por Empatía , Enfermeras y Enfermeros , Atención de Enfermería , Estudios Transversales , Empatía , Humanos , Satisfacción en el Trabajo , Calidad de Vida , República de Corea , Encuestas y Cuestionarios
7.
J Nurs Manag ; 28(3): 682-689, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32072694

RESUMEN

AIM: This study aimed to examine the association between workplace incivility and compassion competence of Korean nurses, as well as the moderating effect of psychological capital. BACKGROUND: Workplace incivility affects the quality of patient care and as such is worthy of critical examination regarding its impact on the compassion competence of nurses. METHODS: In this descriptive cross-sectional study, data for 192 Korean hospital nurses were used to analyse the relationship between workplace incivility and compassion competence and the moderating effect of psychological capital. RESULTS: Workplace incivility was negatively associated with compassion competence of nurses. Furthermore, psychological capital had a conditional moderating effect on the relationship between workplace incivility and nurses' compassion competence. The negative associations of workplace incivility with compassion competence were significant at low and medium levels of psychological capital but not at high psychological capital. Moreover, the association was stronger for those with low psychological capital. CONCLUSION: Workplace incivility is negatively associated with compassion competence among nurses, and psychological capital has conditional moderating effects in its relationship. IMPLICATIONS FOR NURSING MANAGEMENT: Management efforts to reduce workplace incivility and to improve nurses' psychological capital are needed to improve patient care quality.


Asunto(s)
Desgaste por Empatía/etiología , Incivilidad/fisiología , Enfermeras y Enfermeros/psicología , Capital Social , Adulto , Desgaste por Empatía/psicología , Estudios Transversales , Femenino , Humanos , Satisfacción en el Trabajo , Masculino , República de Corea , Encuestas y Cuestionarios , Lugar de Trabajo/psicología , Lugar de Trabajo/normas
8.
J Sch Nurs ; 36(6): 423-429, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30991883

RESUMEN

Longer sedentary time and insufficient sleep are common and potentially serious problems among adolescents and have substantially adverse effects on their physical and mental health. In this school-based study, we conducted an ecological momentary assessment using actigraphy to examine the within-subject association between sedentary time and sleep duration among 80 Korean adolescents aged 12-17. Objectively measured sedentary time and sleep duration were recorded over 5 days; participants also completed a self-reported questionnaire and sleep logs. Using a generalized estimating equation, analysis revealed that daily sedentary time was significantly and negatively associated with sleep duration (ß = -.36, p = .028). Additionally, the interaction between age and sedentary time significantly affected sleep duration (ß = .03, p = .012). These findings suggest the need for school-based interventions that aim to reduce sedentary time and thereby improve sleep duration, helping adolescents, especially younger ones, to achieve a healthier lifestyle.


Asunto(s)
Conducta Sedentaria , Sueño , Adolescente , Humanos , República de Corea , Privación de Sueño , Factores de Tiempo
9.
J Sch Nurs ; 36(2): 104-111, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30079804

RESUMEN

Parents' recognition of adolescents' emotional distress is a significant determinant of early detection and treatment of mental disorders. However, there is dearth of research exploring parent-adolescent agreement regarding adolescents' emotional distress. This cross-sectional, school-based study compared parents' proxy reports and self-reports of adolescent's emotional distress among 289 parent-adolescent dyads in Korea. Findings revealed low agreement between adolescents' and parents' reports of depression, anxiety, and anger, with an average polychoric r of .25 to .27. The agreement was particularly low for high school students, boys, and father-adolescent dyads. Additionally, parents tended to underestimate adolescents' emotional distress symptoms; a significant percentage of adolescents experiencing symptoms were rated in the normal range by parents, particularly high school students experiencing anger. Interventions are needed to help adolescents learn to manage and express their negative emotions. Moreover, parent education programs that improve parents' recognition of emotional distress and appropriate help-seeking behaviors are needed.


Asunto(s)
Ira , Ansiedad , Depresión , Padres/psicología , Distrés Psicológico , Estudiantes/psicología , Adolescente , Adulto , Niño , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Apoderado , República de Corea/epidemiología , Autoinforme , Autoevaluación (Psicología) , Encuestas y Cuestionarios
10.
Fish Shellfish Immunol ; 93: 161-173, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31319209

RESUMEN

Two liver-expressed antimicrobial peptide 2 (LEAP2) isoforms were characterized in a primitive chondrostean sturgeon species, Acipenser baerii (Acipenseriformes). A. baerii LEAP2 isoforms represented essentially common structures shared by their vertebrate orthologs at both genomic (i.e., tripartite organization) and peptide (two conserved disulfide bonds) levels. A. baerii LEAP2 isoforms (designed LEAP2AB and LEAP2C, respectively) phylogenetically occupy the most basal position in the actinopterygian lineage and represent an intermediate character between teleostean and tetrapodian LEAP2s in the sequence alignment. Molecular phylogenetic analysis including LEAP2s from extant primitive fish species indicated that the evolutionary origin of ancestral LEAP2 in vertebrate groups should date back to earlier than the actinopterygian-sarcopterygian split. Gene expression assays under both basal and stimulated conditions suggested that A. baerii LEAP2 isoforms have undergone substantial subfunctionalization in tissue distribution pattern, developmental/ontogenetic expression, and immune responses. LEAP2AB showed a predominant liver expression, while LEAP2C exhibited the highest level of expression in the intestine. LEAP2C was a more dominantly expressed isoform during embryonic development and prelarval ontogeny. The LEAP2AB isoform is more closely associated with innate immune response to microbial invasion, compared with LEAP2C, as evidenced by results from LPS, poly(I:C) and Aeromonas hydrophila challenges. Synthetic mature peptides of LEAP2AB displayed a more potent antimicrobial activity than did LEAP2C. Data from this study could be useful not only to provide deeper insights into the evolutionary mechanism of LEAP2 in the actinopterygian lineage but also to better understand the innate immunity of this commercially important chondrostean species.


Asunto(s)
Enfermedades de los Peces/inmunología , Peces/genética , Peces/inmunología , Regulación de la Expresión Génica/inmunología , Hepcidinas/genética , Hepcidinas/inmunología , Inmunidad Innata/genética , Aeromonas hydrophila/fisiología , Secuencia de Aminoácidos , Animales , Femenino , Proteínas de Peces/química , Proteínas de Peces/genética , Proteínas de Peces/inmunología , Perfilación de la Expresión Génica/veterinaria , Infecciones por Bacterias Gramnegativas/inmunología , Infecciones por Bacterias Gramnegativas/veterinaria , Hepcidinas/química , Lipopolisacáridos/farmacología , Filogenia , Poli I-C/farmacología , Alineación de Secuencia/veterinaria
11.
Fish Shellfish Immunol ; 88: 117-125, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30802630

RESUMEN

Hepcidin, a cysteine-rich antimicrobial peptide (AMP), plays key roles as a regulatory hormone in iron homeostasis, providing a link between iron metabolism and innate immunity. Unlike many other AMPs displaying a high degree of sequence variability among closely related organisms, hepcidin is highly conserved from teleosts to mammals. However, little is known about the early ancestry of hepcidins in the vertebrate lineage. Here, we first report potential a prototype hepcidin from the Siberian sturgeon Acipenser baerii, a primitive chondrostean species. The A. baerii hepcidin (AbHAMP) gene showed a tripartite exon-intron organization, which encoded a precursor protein comprised of three structural signatures containing eight cysteine residues, a common structure in vertebrate hepcidin genes and proteins. mRNA expression by iron-overloading and bacterial infection and antibacterial activity revealed that AbHAMP might play a role in iron metabolism regulator in the liver, and in direct and/or indirect host immune response in the kidney against invading pathogen. Comparison of gene and protein sequences reveled that AbHAMP possesses intermediate characteristics between tetrapodian and teleostean hepcidins (HAMP1s). Phylogenetically, AbHAMP had a closer genetic affiliation to tetrapodian orthologs than to teleostean orthologs, suggesting that the structures of this chondrostean hepcidin may closely reflect the structures of an evolutionarily ancestral form that might have evolved into extant hepcidins in tetrapods and teleosts, respectively. Based on the identification of hepcidin from the chondrostean group, the emergence of the common ancestral hepcidin should be traced back to in early Osteichthyes: no later than sarcopterygian (lobe-finned fishes) - actinopterygian (ray-finned fishes) split.


Asunto(s)
Peces/genética , Secuencia de Aminoácidos , Animales , Bacterias , Infecciones Bacterianas/inmunología , Infecciones Bacterianas/veterinaria , Evolución Biológica , Proteínas de Peces , Peces/metabolismo , Peces/microbiología , Hepcidinas , Inmunidad Innata/genética , Hierro/metabolismo , Hígado/metabolismo , Filogenia , Alineación de Secuencia
12.
Fish Shellfish Immunol ; 93: 683-693, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31408729

RESUMEN

Fish skin mucus is considered to act as the first line of defense against waterborne pathogens and to be potential source of novel antimicrobial components. Here we report the purification and characterization of a novel hepcidin type 2-like antimicrobial peptide (TpHAMP2) from the skin mucus of the pufferfish Takifugu pardalis. The purified TpHAMP2 comprised of 23 amino acids (AAs) with eight Cys residues that form four intramolecular disulfide bonds. The TpHAMP2 gene shared overall structural characteristics with all known hepcidins, which have a tripartite exon-intron gene organization and three structural signatures in the precursor protein. Phylogenetically, TpHAMP2 was classified as HAMP2 class in acanthopterygian fish. Interestingly, the AA sequence of TpHAMP2 did not contain a proprotein cleavage site (RXXR motif) that conserved in most hepcidins and showed a highly positive charged (RKR-) short N-terminus and Val18 and Gly22 residues, which are distinctive structures compared to other known active hepcidins. Recombinant TpHAMP2 identical to the native form exhibited a broad spectrum and potent antimicrobial activity against tested gram-positive and -negative bacteria. Expression of TpHAMP2 mRNA was predominant in the liver and was upregulated in the liver, the spleen, the intestine, and the skin of T. pardalis post immune challenge. Thus, our findings suggests that TpHAMP2 might be of importance in the framework of discovering the fish hepcidins, especially type 2s, and provide noteworthy insight into its gene structure and expression and in the innate immunity as well as the mucosal immunity in regard to hepcidins' evolutionary history in fish species.


Asunto(s)
Enfermedades de los Peces/inmunología , Regulación de la Expresión Génica/inmunología , Hepcidinas/genética , Hepcidinas/inmunología , Inmunidad Innata/genética , Takifugu/genética , Takifugu/inmunología , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Femenino , Proteínas de Peces/química , Proteínas de Peces/genética , Proteínas de Peces/inmunología , Perfilación de la Expresión Génica/veterinaria , Hepcidinas/química , Inmunidad Mucosa/genética , Masculino , Filogenia , Alineación de Secuencia/veterinaria
13.
Fish Shellfish Immunol ; 79: 351-362, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29753144

RESUMEN

Invertebrates, unlike vertebrates which have adaptive immune system, rely heavily on the innate immune system for the defense against pathogenic bacteria. Lysozymes, along with other immune effectors, are regarded as an important group in this defense. An invertebrate-type (i-type) lysozyme, designated Urechis unicinctus invertebrate-type lysozyme, Uu-ilys, has been isolated from nephridia of Urechis unicinctus using a series of high performance liquid chromatography (HPLC), and ultrasensitive radial diffusion assay (URDA) as a bioassay system. Analyses of the primary structure and cDNA cloning revealed that Uu-ilys was approximately 14 kDa and composed of 122 amino acids (AAs) of which the precursor had a total of 160 AAs containing a signal peptide of 18 AAs and a pro-sequence of 20 AAs encoded by the nucleotide sequence of 714 bp that comprises a 5' untranslated region (UTR) of 42 bp, an open reading frame (ORF) of 483 bp, and a 3' UTR of 189 bp. Multiple sequence alignment showed Uu-ilys has high homology to i-type lysozymes from several annelids. Relatively high transcriptional expression levels of Uu-ilys was detected in nephridia, anal vesicle, and intestine. The native Uu-ilys exhibited comparable lysozyme enzymatic and antibacterial activities to hen egg white lysozyme. Collectively, these data suggest that Uu-ilys, the isolated antibacterial protein, plays a role in the immune defense mechanism of U. unicinctus. Recombinant Uu-ilys (rUu-ilys) produced in a bacterial expression system showed significantly decreased lysozyme lytic activity from that of the native while its potency on radial diffusion assay detecting antibacterial activity was retained, which may indicate the non-enzymatic antibacterial capacity of Uu-ilys.


Asunto(s)
Anélidos/genética , Anélidos/inmunología , Regulación de la Expresión Génica/inmunología , Inmunidad Innata/genética , Muramidasa/genética , Muramidasa/inmunología , Secuencia de Aminoácidos , Animales , Anélidos/enzimología , Proteínas de Artrópodos/química , Proteínas de Artrópodos/genética , Proteínas de Artrópodos/inmunología , Secuencia de Bases , Perfilación de la Expresión Génica , Muramidasa/química , Filogenia , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/inmunología , Alineación de Secuencia
14.
Geriatr Nurs ; 39(6): 623-628, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30054094

RESUMEN

Given South Korea's rapidly aging population, mental health and quality of life (QoL) in older adults are increasingly becoming important. Self-compassion (SC), defined as extending compassion to oneself in times of suffering, has been found to have associations with positive mental health outcomes. This study was performed to examine associations between self-compassion and mental health symptoms, sleep disturbance, life satisfaction, and health-related quality of life (HR-QoL) among older Korean adults. The participants in this cross-sectional study included 203 older Korean adults aged 65 and over. Findings of this study suggest that self-compassion in older adults protects them from developing mental health and sleep disturbance symptoms while enhancing their life satisfaction, self-care, and usual activities. Therefore, interventions fostering self-compassion may benefit older adults' mental health and quality of life.


Asunto(s)
Empatía , Salud Mental , Calidad de Vida/psicología , Autocuidado/psicología , Sueño , Anciano , Anciano de 80 o más Años , Estudios Transversales , Femenino , Humanos , Masculino , Satisfacción Personal , República de Corea , Trastornos del Sueño-Vigilia/prevención & control , Encuestas y Cuestionarios
15.
J Biol Chem ; 290(34): 21042-21053, 2015 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-26116716

RESUMEN

The molecular characterization of symbionts is pivotal for understanding the cross-talk between symbionts and hosts. In addition to valuable knowledge obtained from symbiont genomic studies, the biochemical characterization of symbionts is important to fully understand symbiotic interactions. The bean bug (Riptortus pedestris) has been recognized as a useful experimental insect gut symbiosis model system because of its cultivatable Burkholderia symbionts. This system is greatly advantageous because it allows the acquisition of a large quantity of homogeneous symbionts from the host midgut. Using these naïve gut symbionts, it is possible to directly compare in vivo symbiotic cells with in vitro cultured cells using biochemical approaches. With the goal of understanding molecular changes that occur in Burkholderia cells as they adapt to the Riptortus gut environment, we first elucidated that symbiotic Burkholderia cells are highly susceptible to purified Riptortus antimicrobial peptides. In search of the mechanisms of the increased immunosusceptibility of symbionts, we found striking differences in cell envelope structures between cultured and symbiotic Burkholderia cells. The bacterial lipopolysaccharide O antigen was absent from symbiotic cells examined by gel electrophoretic and mass spectrometric analyses, and their membranes were more sensitive to detergent lysis. These changes in the cell envelope were responsible for the increased susceptibility of the Burkholderia symbionts to host innate immunity. Our results suggest that the symbiotic interactions between the Riptortus host and Burkholderia gut symbionts induce bacterial cell envelope changes to achieve successful gut symbiosis.


Asunto(s)
Burkholderia/química , Pared Celular/química , Heterópteros/microbiología , Antígenos O/química , Simbiosis , Animales , Péptidos Catiónicos Antimicrobianos/farmacología , Burkholderia/efectos de los fármacos , Burkholderia/metabolismo , Burkholderia/fisiología , Membrana Celular/química , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Pared Celular/efectos de los fármacos , Pared Celular/metabolismo , Tracto Gastrointestinal/efectos de los fármacos , Tracto Gastrointestinal/inmunología , Tracto Gastrointestinal/metabolismo , Tracto Gastrointestinal/microbiología , Heterópteros/inmunología , Heterópteros/metabolismo , Antígenos O/metabolismo
16.
J Neurochem ; 137(1): 33-45, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26801824

RESUMEN

Neuropeptides that act as muscle relaxants have been identified in chordates and protostomian invertebrates but little is known about the molecular identity of neuropeptides that act as muscle relaxants in deuterostomian invertebrates (e.g. echinoderms) that are 'evolutionary intermediates' of chordates and protostomes. Here, we have used the apical muscle of the starfish Patiria pectinifera to assay for myorelaxants in extracts of this species. A hexadecapeptide with the amino acid sequence Phe-Gly-Lys-Gly-Gly-Ala-Tyr-Asp-Pro-Leu-Ser-Ala-Gly-Phe-Thr-Asp was identified and designated starfish myorelaxant peptide (SMP). Cloning and sequencing of a cDNA encoding the SMP precursor protein revealed that it comprises 12 copies of SMP as well as 3 peptides (7 copies in total) that are structurally related to SMP. Analysis of the expression of SMP precursor transcripts in P. pectinifera using qPCR revealed the highest expression in the radial nerve cords and lower expression levels in a range of neuromuscular tissues, including the apical muscle, tube feet and cardiac stomach. Consistent with these findings, SMP also caused relaxation of tube foot and cardiac stomach preparations. Furthermore, SMP caused relaxation of apical muscle preparations from another starfish species - Asterias amurensis. Collectively, these data indicate that SMP has a general physiological role as a muscle relaxant in starfish. Interestingly, comparison of the sequence of the SMP precursor with known neuropeptide precursors revealed that SMP belongs to a bilaterian family of neuropeptides that include molluscan pedal peptides (PP) and arthropodan orcokinins (OK). This is the first study to determine the function of a PP/OK-type peptide in a deuterostome. Pedal peptide/orcokinin (PP/OK)-type peptides are a family of structurally related neuropeptides that were first identified and functionally characterised in protostomian invertebrates. Here, we report the discovery of starfish myorelaxant peptide (SMP), a novel member of the PP/OK-type neuropeptide identified in the starfish Patiria pectinifera (phylum Echinodermata). SMP is the first PP/OK-type neuropeptide to be functionally characterised in a deuterostome.


Asunto(s)
Relajación Muscular/efectos de los fármacos , Fármacos Neuromusculares/aislamiento & purificación , Neuropéptidos/aislamiento & purificación , Estrellas de Mar/química , Secuencia de Aminoácidos , Animales , Asterias , Secuencia de Bases , Clonación Molecular , ADN Complementario/genética , Datos de Secuencia Molecular , Músculos/efectos de los fármacos , Neuropéptidos/genética , Neuropéptidos/farmacología , Neuropéptidos/fisiología , Precursores de Proteínas/genética , ARN Mensajero/biosíntesis , Alineación de Secuencia , Homología de Secuencia de Aminoácido
17.
EMBO J ; 31(12): 2770-83, 2012 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-22549468

RESUMEN

Caspases have been extensively studied as critical initiators and executioners of cell death pathways. However, caspases also take part in non-apoptotic signalling events such as the regulation of innate immunity and activation of nuclear factor-κB (NF-κB). How caspases are activated under these conditions and process a selective set of substrates to allow NF-κB signalling without killing the cell remains largely unknown. Here, we show that stimulation of the Drosophila pattern recognition protein PGRP-LCx induces DIAP2-dependent polyubiquitylation of the initiator caspase DREDD. Signal-dependent ubiquitylation of DREDD is required for full processing of IMD, NF-κB/Relish and expression of antimicrobial peptide genes in response to infection with Gram-negative bacteria. Our results identify a mechanism that positively controls NF-κB signalling via ubiquitin-mediated activation of DREDD. The direct involvement of ubiquitylation in caspase activation represents a novel mechanism for non-apoptotic caspase-mediated signalling.


Asunto(s)
Proteínas Portadoras/metabolismo , Caspasas/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila/inmunología , Regulación de la Expresión Génica , Bacterias Gramnegativas/inmunología , Proteínas Inhibidoras de la Apoptosis/metabolismo , Ubiquitinación , Animales , Péptidos Catiónicos Antimicrobianos/biosíntesis , Drosophila/genética , Drosophila/microbiología , Inmunidad Innata , Modelos Biológicos , FN-kappa B/metabolismo , Factores de Transcripción/metabolismo
18.
Fish Shellfish Immunol ; 52: 289-97, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-27033467

RESUMEN

A 4.7 kDa antimicrobial peptide was purified from the acidified gill extract of the Abalone, Haliotis discus, by cation-exchange and C18 reversed-phase high performance liquid chromatography (HPLC). Comparison of the amino acid sequences and molecular weight of this peptide with those of other known antimicrobial peptides revealed that this antimicrobial peptide have high sequence homology with that of cgMolluscidin and was designated hdMolluscidin. hdMolluscidin is composed of 46 amino acid residues containing several dibasic residue repeats like KK or K-R. hdMolluscidin showed potent antimicrobial activity against both Gram-positive bacteria including Bacillus subtilis and Staphylococcus aureus (minimal effective concentrations [MECs]; 0.8-19.0 µg/mL) and Gram-negative bacteria including Aeromonas hydrophila, Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica, Shigella flexneri, and Vibrio parahemolyticus ([MECs]; 1.0-4.0 µg/mL) without hemolytic activity. However, hdMolluscidin did not show any significant activity against Candida albicans. The secondary structural prediction suggested that hdMolluscidin might not form an ordered or an amphipathic structure. hdMolluscidin did not show membrane permeabilization or leakage ability. The full-length hdMolluscidin cDNA contained 566-bp, including a 5'-untranslated region (UTR) of 63-bp, a 3'-UTR of 359-bp, and an open reading frame of 144-bp encoding 47 amino acids (containing Met). cDNA study of hdMolluscidin suggests that it is expressed as a mature peptide. Our results indicate that hdMolluscidin could relate to the innate immune defenses in abalone and it may not act directly on bacterial membrane.


Asunto(s)
Péptidos Catiónicos Antimicrobianos/genética , Gastrópodos/genética , Gastrópodos/inmunología , Secuencia de Aminoácidos , Animales , Péptidos Catiónicos Antimicrobianos/química , Péptidos Catiónicos Antimicrobianos/metabolismo , Secuencia de Bases , Candida albicans/fisiología , Clonación Molecular , ADN Complementario/genética , ADN Complementario/metabolismo , Gastrópodos/metabolismo , Gastrópodos/microbiología , Branquias/química , Branquias/inmunología , Branquias/microbiología , Bacterias Gramnegativas/fisiología , Bacterias Grampositivas/fisiología , Estructura Secundaria de Proteína , Alineación de Secuencia
19.
J Pept Sci ; 22(10): 628-635, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27506561

RESUMEN

A bioactive peptide mimicking peptide-signaling molecules has been isolated from the skin extract of fish Channa argus which caused contraction of the apical muscle of a starfish Patiria pectinifera, a deuterostomian invertebrate. The primary structure of the isolated pentapeptide comprises amino acid sequence of H-Pro-Ala-Leu-Ala-Leu-OH (PALAL) with a molecular mass of 483.7 Da. Pharmacological activity of PALAL, dosage ranging from 10-9 to 10-5 M, revealed concentration-dependent contraction of the apical muscles of P. pectinifera and Asterias amurensis. However, PALAL was not active on the intestinal smooth muscle of the goldfish Carassius auratus and has presumably other physiological roles in fish skin. Investigation of structure-activity relationship using truncated and substituted analogs of PALAL demonstrated that H-Ala-Leu-Ala-Leu-OH was necessary and should be sufficient to constrict apical muscle of P. pectinifera. Furthermore, the second alanine residue was required to display the activity, and the fifth leucine residue was responsible for its potency. Comparison with PALAL's primary structure with those of other known bioactive peptides from fish and starfish revealed that PALAL does not have any significant homology. Consequently, PALAL is a bioactive peptide that elicits a muscle contraction in starfish, and the isolation of PALAL may lead to develop other bioactive peptides sharing its similar sequence and/or activity. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.


Asunto(s)
Proteínas de Peces/farmacología , Contracción Muscular/efectos de los fármacos , Músculos/efectos de los fármacos , Oligopéptidos/farmacología , Piel/química , Secuencia de Aminoácidos , Animales , Relación Dosis-Respuesta a Droga , Proteínas de Peces/síntesis química , Proteínas de Peces/aislamiento & purificación , Peces/metabolismo , Peso Molecular , Contracción Muscular/fisiología , Músculos/fisiología , Oligopéptidos/síntesis química , Oligopéptidos/aislamiento & purificación , Estrellas de Mar/efectos de los fármacos , Estrellas de Mar/fisiología , Relación Estructura-Actividad
20.
J Biol Chem ; 289(29): 20092-101, 2014 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-24891502

RESUMEN

In Drosophila, the Imd pathway is activated by diaminopimelic acid-type peptidoglycan and triggers the humoral innate immune response, including the robust induction of antimicrobial peptide gene expression. Imd and Relish, two essential components of this pathway, are both endoproteolytically cleaved upon immune stimulation. Genetic analyses have shown that these cleavage events are dependent on the caspase-8 like Dredd, suggesting that Imd and Relish are direct substrates of Dredd. Among the seven Drosophila caspases, we find that Dredd uniquely promotes Imd and Relish processing, and purified recombinant Dredd cleaves Imd and Relish in vitro. In addition, interdomain cleavage of Dredd is not required for Imd or Relish processing and is not observed during immune stimulation. Baculovirus p35, a suicide substrate of executioner caspases, is not cleaved by purified Dredd in vitro. Consistent with this biochemistry but contrary to earlier reports, p35 does not interfere with Imd signaling in S2* cells or in vivo.


Asunto(s)
Caspasas/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila/metabolismo , Factores de Transcripción/metabolismo , Proteínas Virales/metabolismo , Secuencia de Aminoácidos , Sustitución de Aminoácidos , Animales , Animales Modificados Genéticamente , Caspasa 8/metabolismo , Caspasas/química , Caspasas/genética , Línea Celular , Drosophila/genética , Drosophila/inmunología , Proteínas de Drosophila/química , Proteínas de Drosophila/genética , Femenino , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Dominios y Motivos de Interacción de Proteínas , Procesamiento Proteico-Postraduccional , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Transducción de Señal , Especificidad por Sustrato
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