Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
1.
Front Microbiol ; 14: 1265216, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37901835

RESUMEN

Thermophily is an ancient trait among microorganisms. The molecular principles to sustain high temperatures, however, are often described as adaptations, somewhat implying that they evolved from a non-thermophilic background and that thermophiles, i.e., organisms with growth temperature optima (TOPT) above 45°C, evolved from mesophilic organisms (TOPT 25-45°C). On the contrary, it has also been argued that LUCA, the last universal common ancestor of Bacteria and Archaea, may have been a thermophile, and mesophily is the derived trait. In this study, we took an experimental approach toward the evolution of a mesophile from a thermophile. We selected the acetogenic bacterium T. kivui (TOPT 66°C) since acetogenesis is considered ancient physiology and cultivated it at suboptimal low temperatures. We found that the lowest possible growth temperature (TMIN) under the chosen conditions was 39°C. The bacterium was subsequently subjected to adaptive laboratory evolution (ALE) by serial transfer at 45°C. Interestingly, after 67 transfers (approximately 180 generations), the adapted strain Adpt45_67 did not grow better at 45°C, but a shift in the TOPT to 60°C was observed. Growth at 45°C was accompanied by a change in the morphology as shorter, thicker cells were observed that partially occurred in chains. While the proportion of short-chain fatty acids increased at 50°C vs. 66°C in both strains, Adpt45_67 also showed a significantly increased proportion of plasmalogens. The genome analysis revealed 67 SNPs compared to the type strain, among these mutations in transcriptional regulators and in the cAMP binding protein. Ultimately, the molecular basis of the adaptation of T. kivui to a lower TOPT remains to be elucidated. The observed change in phenotype is the first experimental step toward the evolution of thermophiles growing at colder temperatures and toward a better understanding of the cold adaptation of thermophiles on early Earth.

2.
BMJ Open ; 13(3): e059016, 2023 03 08.
Artículo en Inglés | MEDLINE | ID: mdl-36889825

RESUMEN

OBJECTIVES: This study aims to evaluate whether the use of thyroid ultrasound (US) early in the work-up of suspected thyroid disorders triggers cascade effects of medical procedures and to analyse effects on morbidity, healthcare usage and costs. STUDY DESIGN: Retrospective analysis of claims data from ambulatory care (2012-2017). SETTING: Primary care in Bavaria, Germany, 13 million inhabitants. PARTICIPANTS: Patients having received a thyroid stimulating hormone (TSH) test were allocated to (1) observation group: TSH test followed by an early US within 28 days or (2) control group: TSH test, but no early US. Propensity score matching was used adjusting for socio-demographic characteristics, morbidity and symptom diagnosis (N=41 065 per group after matching). PRIMARY AND SECONDARY OUTCOME MEASURES: Using cluster analysis, groups were identified regarding frequency of follow-up TSH tests and/or US and compared. RESULTS: Four subgroups were identified: cluster 1: 22.8% of patients, mean (M)=1.6 TSH tests; cluster 2: 16.6% of patients, M=4.7 TSH tests; cluster 3: 54.4% of patients, M=3.3 TSH tests, 1.8 US; cluster 4: 6.2% of patients, M=10.9 TSH tests, 3.9 US. Overall, reasons that explain the tests could rarely be found. An early US was mostly found in clusters 3 and 4 (83.2% and 76.1%, respectively, were part of the observation group). In cluster 4 there were more women, thyroid-specific morbidity and costs were higher and the early US was more likely to be performed by specialists in nuclear medicine or radiologists. CONCLUSION: Presumably unnecessary tests in the field of suspected thyroid diseases seem to be frequent, contributing to cascades effects. Neither German nor international guidelines provide clear recommendations for or against US screening. Therefore, guidelines on when to apply US and when not are urgently needed.


Asunto(s)
Enfermedades de la Tiroides , Humanos , Femenino , Estudios Retrospectivos , Enfermedades de la Tiroides/diagnóstico por imagen , Tirotropina , Atención Ambulatoria
3.
Sci Rep ; 12(1): 2473, 2022 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-35169235

RESUMEN

The purpose of this study was to evaluate the performance of machine learning algorithms to predict trabeculectomy surgical outcomes. Preoperative systemic, demographic and ocular data from consecutive trabeculectomy surgeries from a single academic institution between January 2014 and December 2018 were incorporated into models using random forest, support vector machine, artificial neural networks and multivariable logistic regression. Mean area under the receiver operating characteristic curve (AUC) and accuracy were used to evaluate the discrimination of each model to predict complete success of trabeculectomy surgery at 1 year. The top performing model was optimized using recursive feature selection and hyperparameter tuning. Calibration and net benefit of the final models were assessed. Among the 230 trabeculectomy surgeries performed on 184 patients, 104 (45.2%) were classified as complete success. Random forest was found to be the top performing model with an accuracy of 0.68 and AUC of 0.74 using 5-fold cross-validation to evaluate the final optimized model. These results provide evidence that machine learning models offer value in predicting trabeculectomy outcomes in patients with refractory glaucoma.


Asunto(s)
Glaucoma/cirugía , Aprendizaje Automático , Trabeculectomía , Anciano , Anciano de 80 o más Años , Femenino , Predicción , Humanos , Masculino , Persona de Mediana Edad , Curva ROC , Resultado del Tratamiento
5.
Aerosp Med Hum Perform ; 91(12): 940-947, 2020 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-33243337

RESUMEN

BACKGROUND: In their working life, airline pilots are exposed to particular risk factors that promote nonspecific low back pain (LBP). Because of the varying incidence internationally, we evaluated the point prevalences of acute, subacute, and chronic nonspecific LBP, as well as the current prevalences in German airline pilots. Furthermore, we compared the prevalence to the general German population and to European counterparts.METHODS: An anonymous online survey of 698 participating German airline pilots was evaluated. The impairment between groups was analyzed. Prevalences from our data were compared to existing data.RESULTS: The following point prevalences were found: 8.2% acute, 2.4% subacute, 82.7% chronic LBP; 74.1% of all individuals were suffering from current LBP when answered the questionnaire. A total time spent flying greater than 600 h within the last 12 mo was significantly related to acute nonspecific LBP. Individuals with any type of LBP were significantly impaired compared to those unaffected. It was found that German airline pilots suffer more often from current LBP than the general population and have a higher point prevalence of total LBP than their European counterparts.CONCLUSIONS: The evaluation showed a surprisingly high, previously unidentified, prevalence of nonspecific LBP in German airline pilots. Why German airline pilots suffer more often from LBP remains uncertain. The number of flying hours appears to have a negative effect on developing acute low back pain, but causation cannot be concluded. Other risk factors could not be confirmed.Albermann M, Lehmann M, Eiche C, Schmidt J, Prottengeier J. Low back pain in commercial airline pilots. Aerosp Med Hum Perform. 2020; 91(12):940947.


Asunto(s)
Dolor de la Región Lumbar , Pilotos , Humanos , Dolor de la Región Lumbar/epidemiología , Prevalencia , Factores de Riesgo , Encuestas y Cuestionarios
6.
Artículo en Español | LILACS, BNUY, UY-BNMED | ID: biblio-1088701

RESUMEN

Objetivos: Evaluar los datos clínicos obtenido en la policlínica de Salud Sexual y Reproductiva del Hospital Universitario a los 6 años de la implementación de la ley de interrupción voluntaria del embarazo (IVE). Métodos: revisión de historias clínicas de diciembre de 2012 a diciembre de 2018. Resultados: de 448 pacientes, 361 completaron el proceso IVE, 63 requirieron una segunda dosis de Misoprostol. Cuarenta pacientes decidieron continuar sus embarazos y siguieron con el control en el servicio y 32 no volvieron tras su primera entrevista. Conclusiones: basado en los resultados de la investigación, el procedimiento médico de IVE es efectivo en todos los casos, solo en 33 pacientes se requirió procedimientos quirúrgicos adicionales. La ley IVE representa un progreso considerable en la salud reproductiva de la mujer uruguaya. La IVE ha asegurado asistencia médica, salud y el respeto a los derechos reproductivos sexuales y humanos, incluyendo oportunidad, continuidad y humanización de la interrupción del embarazo. La existencia de la ley de por sí no garantiza que las mujeres opten por abortar.


Aims: To evaluate clinical data from the Sexual and Reproductive Health Clinic of the University Hospital six years after the implementation of the voluntary interruption of pregnancy law (VIP). Methods: revision of clinical records from December 2012 to December 2018. Results: Out of 448 patients, 361 interrupted their pregnancies. 63 patients required a second dose of Misoprostol, 30 patients required additional medical interventions, 49 patients decided to continue their pregnancies and were provided assistance, and 32 did not return following their first interview. Conclusions: Based on the research findings, the medical procedure of VIP is effective in all the cases, just 33 needs surgical additional process. The VIP law represents a considerable progress in the reproductive health of Uruguayan women. As a result, there is a higher rate of abortions in the country. VIP has ensured medical assistance, healthcare and respect for sexual and human reproductive rights, including opportunity, continuity, and humanization of pregnancy interruption. The existence of the law per se does not ensure that women will opt for abortion.


Objetivos: Avaliar os dados clínicos obtidos na Policlínica de Saúde Sexual e Reprodutiva do Hospital Universitário 6 anos após a implementação da lei da interrupção voluntária da gravidez (IVE). Métodos: revisão de historias de dezembro de 2012 a dezembro de 2018. Resultados: Dos 448 pacientes, 361 completaram o processo IVE, 63 necessitaram de uma segunda dose de Misoprostol. Quarenta y nove pacientes decidiram continuar suas gestações e continuei o controle no serviço e 32 não retornaram após a primeira entrevista. Conclusões: Com base nos resultados da investigação, o procedimento médico do IVE é eficaz em todos os casos, apenas em 33 pacientes foram necessários procedimentos cirúrgicos adicionais. A lei do IVE representa um progresso considerável na saúde reprodutiva das mulheres uruguaias. O IVE assegurou cuidados médicos, saúde e respeito pelos direitos sexuais e reprodutivos humanos, incluindo oportunidades, continuidade e humanização da interrupção de gravidez a existência da lei em si não garante que as mulheres a optar por abortar.


Asunto(s)
Humanos , Femenino , Adolescente , Adulto , Aborto Legal/legislación & jurisprudencia , Aborto Legal/estadística & datos numéricos , Uruguay , Epidemiología Descriptiva , Estudios Retrospectivos , Aborto Legal/métodos , Evaluación del Impacto en la Salud
7.
BMJ Open ; 9(7): e028092, 2019 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-31289077

RESUMEN

INTRODUCTION: (Over)exposure to ultraviolet radiation is a major risk factor for skin cancer. The Global Solar Ultraviolet Index (UVI) was introduced by the WHO and partner organisations in 1995 as a simple measure of the intensity of solar UV radiation, providing guidance for the population to use appropriate sun protective measures. Little is known about the impact of the UVI on actual sun protection behaviour. Our systematic review aims to assess global levels of awareness, understanding and use of the UVI as prerequisites for the preventive effectiveness of this public health tool. METHODS AND ANALYSIS: Systematic searches will be performed in 10 electronic literature databases including Medline, Scopus and Web of Science-Core Collection, two clinical trials registries and at least two grey literature databases (OpenGrey, Bielefeld Academic Search Engine). Additional literature sources will be retrieved using hand search of reference lists of included studies and snowballing methods. We will include studies with all types of quantitative study designs and participants reporting on at least one outcome in the three main categories (i) awareness, (ii) understanding and (iii) use of the UVI. We will assess the risk of bias within studies with an abbreviated version of the AXIS tool, designed specifically for cross-sectional studies. As we expect large heterogeneity in outcomes, we will conduct a narrative synthesis of results instead of a meta-analysis. ETHICS AND DISSEMINATION: Ethical approval and patient consent are not required as this is a systematic review based on published studies. The results of this study will be published in an international peer-reviewed journal. PROSPERO REGISTRATION NUMBER: CRD42018093693.


Asunto(s)
Conocimientos, Actitudes y Práctica en Salud , Promoción de la Salud/métodos , Neoplasias Cutáneas/prevención & control , Rayos Ultravioleta/efectos adversos , Salud Global , Humanos , Salud Pública , Revisiones Sistemáticas como Asunto
8.
Artículo en Inglés | MEDLINE | ID: mdl-31212727

RESUMEN

Overexposure to ultraviolet (UV) radiation is the main modifiable risk factor for skin cancer. The Global Solar Ultraviolet Index (UVI) was introduced as a tool to visualize the intensity of UV radiation on a certain day, which should enable and encourage people to take appropriate protective measures. The 'low' exposure category of the UVI, defined by a rounded UVI value of 0, 1 or 2, was linked to the health message 'No protection required' by the World Health Organization and partner organizations. However, published evidence corroborating this advice is not available. To evaluate the erythemal risk of low UVI days, we analyzed 14,431 daily time series of ambient erythemal irradiance data measured at nine stations of the German solar UV monitoring network during the years 2007-2016. We analyzed the proportion of days in the sample for which ambient erythemal doses calculated for various time intervals exceed average minimal erythemal doses (MEDs) of the Fitzpatrick skin phototypes I-VI to assess the potential for erythema arising from sun exposure on days with low UVI values. Additionally, we calculated for each day the minimum exposure duration needed to receive one MED. Our results indicate that on days with a UVI value of 0, risk of erythema is indeed negligible. Conversely, the abovementioned health message appears misleading when melano-compromised individuals (skin type I and II) spend more than 1.5 hours outdoors on days with a UVI value of 2. Under rare circumstances of prolonged exposure, MEDs of the two most sensitive skin types can also be exceeded even on days with a UVI value of 1. Hence, current WHO guidance for sun protection on days with low UVI values needs reconsideration.


Asunto(s)
Eritema/etiología , Guías como Asunto , Salud Pública/normas , Neoplasias Cutáneas/prevención & control , Luz Solar/efectos adversos , Rayos Ultravioleta/efectos adversos , Humanos , Factores de Riesgo
9.
Photochem Photobiol ; 95(4): 1076-1082, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-30767232

RESUMEN

According to the World Health Organization and partner organizations, no protection against ultraviolet (UV) radiation is required on days with "low" values (i.e., values <3) of the Global Solar Ultraviolet Index (UVI). Erythemal irradiance (Eer ) data of such days were analyzed to evaluate this claim. Measurements from 9 stations of the German solar UV monitoring network from 2007 to 2016 yielded 14,431 daily Eer time series of low UVI days. Erythemal doses for certain fixed time intervals-acquired from measurements on horizontal planes-were compared with the average minimal erythemal dose (MED) of skin phototype II. Doses from days with rounded UVI values of 0 were insufficient to induce erythema and even on days with rounded UVI values of 1 doses exceeding 1 MED of skin type II could only be acquired under very specific circumstances of prolonged exposure. Conversely, sun exposure on days with rounded UVI values of 2 can indeed provide doses sufficient to induce erythema in skin type II after two hours around noon. In conclusion, our analyses do not support the claim of harmlessness currently associated with the entire low UVI exposure category in public guidance on interpretation of the UVI.


Asunto(s)
Monitoreo del Ambiente , Eritema/etiología , Piel/efectos de la radiación , Luz Solar/efectos adversos , Rayos Ultravioleta/efectos adversos , Alemania , Humanos , Factores de Tiempo
10.
Stud Health Technol Inform ; 243: 25-29, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28883163

RESUMEN

A Global Solar Ultraviolet Index (UVI) value of 2 is generally linked to the health message 'You can safely stay outside!' To examine whether this is sound advice for all skin types and even for prolonged periods spent outside we used erythemal irradiance data of all 136 days during the study period from 2014 till 2016 with such a UVI measured by the German Federal Office for Radiation Protection (BfS) in Munich, Germany. A comparison between the ambient erythemal doses calculated for various time intervals and minimal erythemal doses (MEDs) of the Caucasian skin types I-IV led us to a critical reappraisal of the above health message. Specifically, the message might be misleading if people with a fair complexion want to spend several hours outside, because without any protective measures the doses received can be sufficient to induce erythema. We thus recommend an amendment of the health message related to a safe level of the UVI and, moreover, generally tailoring UVI-related health messages to different skin types. Currently, these messages do not seem to be strictly evidence based, which might be one reason for the unexpected result of our analysis.


Asunto(s)
Eritema , Protección Radiológica , Rayos Ultravioleta , Alemania , Humanos , Valores de Referencia , Luz Solar
11.
Clin Vaccine Immunol ; 22(6): 672-3, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25878253

RESUMEN

To estimate the veterinary importance of Batai virus (BATV), we investigated the presence of BATV-specific antibodies and BATV RNA in 548 bovines from southwest Germany, and we demonstrated that 3 cattle serum samples contained BATV-neutralizing antibodies, resulting in a seroprevalence of 0.55%. Thus, our results confirm local transmission and indicate cattle as potential hosts of BATV in southwest Germany.


Asunto(s)
Anticuerpos Antivirales/sangre , Virus Bunyamwera/inmunología , Virus Bunyamwera/aislamiento & purificación , Infecciones por Bunyaviridae/veterinaria , Enfermedades de los Bovinos/epidemiología , Enfermedades de los Bovinos/virología , ARN Viral/sangre , Animales , Anticuerpos Neutralizantes/sangre , Infecciones por Bunyaviridae/epidemiología , Infecciones por Bunyaviridae/virología , Bovinos , Monitoreo Epidemiológico , Alemania/epidemiología , Estudios Seroepidemiológicos
12.
J Exp Clin Cancer Res ; 33: 59, 2014 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-25011684

RESUMEN

BACKGROUND: Previous studies have shown that class-I histone deacetylase (HDAC) 8 mRNA is upregulated in urothelial cancer tissues and urothelial cancer cell lines compared to benign controls. Using urothelial cancer cell lines we evaluated whether specific targeting of HDAC8 might be a therapeutic option in bladder cancer treatment. METHODS: We conducted siRNA-mediated knockdown and specific pharmacological inhibition of HDAC8 with the three different inhibitors compound 2, compound 5, and compound 6 in several urothelial carcinoma cell lines with distinct HDAC8 expression profiles. Levels of HDAC and marker proteins were determined by western blot analysis and mRNA levels were measured by quantitative real-time PCR. Cellular effects of HDAC8 suppression were analyzed by ATP assay, flow cytometry, colony forming assay and migration assay. RESULTS: Efficient siRNA-mediated knockdown of HDAC8 reduced proliferation up to 45%. The HDAC8 specific inhibitors compound 5 and compound 6 significantly reduced viability of all urothelial cancer cell lines (IC50 9 - 21 µM). Flow cytometry revealed only a slight increase in the sub-G1 fraction indicating a limited induction of apoptosis. Expression of thymidylate synthase was partly reduced; PARP-cleavage was not detected. The influence of the pharmacological inhibition on clonogenic growth and migration show a cell line- and inhibitor-dependent reduction with the strongest effects after treatment with compound 5 and compound 6. CONCLUSIONS: Deregulation of HDAC8 is frequent in urothelial cancer, but neither specific pharmacological inhibition nor siRNA-mediated knockdown of HDAC8 impaired viability of urothelial cancer cell lines in a therapeutic useful manner. Accordingly, HDAC8 on its own is not a promising drug target in bladder cancer.


Asunto(s)
Histona Desacetilasas/genética , Proteínas Represoras/antagonistas & inhibidores , Proteínas Represoras/genética , Neoplasias de la Vejiga Urinaria/enzimología , Neoplasias de la Vejiga Urinaria/terapia , Línea Celular Tumoral , Técnicas de Silenciamiento del Gen , Inhibidores de Histona Desacetilasas/farmacología , Histona Desacetilasas/metabolismo , Humanos , Ácidos Hidroxámicos/farmacología , Terapia Molecular Dirigida , ARN Interferente Pequeño/administración & dosificación , ARN Interferente Pequeño/genética , Proteínas Represoras/metabolismo , Neoplasias de la Vejiga Urinaria/tratamiento farmacológico , Neoplasias de la Vejiga Urinaria/genética
13.
J Virol ; 88(15): 8713-7, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24829349

RESUMEN

The N terminus of arenavirus L protein contains an endonuclease presumably involved in "cap snatching." Here, we employed the Lassa virus replicon system to map other L protein sites that might be involved in this mechanism. Residues Phe-1979, Arg-2018, Phe-2071, Asp-2106, Trp-2173, Tyr-2179, Arg-2200, and Arg-2204 were important for viral mRNA synthesis but dispensable for genome replication. Thus, the C terminus of L protein is involved in the mRNA synthesis process, potentially by mediating cap binding.


Asunto(s)
Virus Lassa/fisiología , ARN Mensajero/genética , ARN Viral/genética , Proteínas Virales/metabolismo , Línea Celular , Humanos , Virus Lassa/genética , Proteínas Virales/genética , Replicación Viral
14.
PLoS Negl Trop Dis ; 8(5): e2804, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24786461

RESUMEN

BACKGROUND: Mice lacking the type I interferon receptor (IFNAR-/- mice) reproduce relevant aspects of Crimean-Congo hemorrhagic fever (CCHF) in humans, including liver damage. We aimed at characterizing the liver pathology in CCHF virus-infected IFNAR-/- mice by immunohistochemistry and employed the model to evaluate the antiviral efficacy of ribavirin, arbidol, and T-705 against CCHF virus. METHODOLOGY/PRINCIPAL FINDINGS: CCHF virus-infected IFNAR-/- mice died 2-6 days post infection with elevated aminotransferase levels and high virus titers in blood and organs. Main pathological alteration was acute hepatitis with extensive bridging necrosis, reactive hepatocyte proliferation, and mild to moderate inflammatory response with monocyte/macrophage activation. Virus-infected and apoptotic hepatocytes clustered in the necrotic areas. Ribavirin, arbidol, and T-705 suppressed virus replication in vitro by ≥3 log units (IC50 0.6-2.8 µg/ml; IC90 1.2-4.7 µg/ml). Ribavirin [100 mg/(kg×d)] did not increase the survival rate of IFNAR-/- mice, but prolonged the time to death (p<0.001) and reduced the aminotransferase levels and the virus titers. Arbidol [150 mg/(kg×d)] had no efficacy in vivo. Animals treated with T-705 at 1 h [15, 30, and 300 mg/(kg×d)] or up to 2 days [300 mg/(kg×d)] post infection survived, showed no signs of disease, and had no virus in blood and organs. Co-administration of ribavirin and T-705 yielded beneficial rather than adverse effects. CONCLUSIONS/SIGNIFICANCE: Activated hepatic macrophages and monocyte-derived cells may play a role in the proinflammatory cytokine response in CCHF. Clustering of infected hepatocytes in necrotic areas without marked inflammation suggests viral cytopathic effects. T-705 is highly potent against CCHF virus in vitro and in vivo. Its in vivo efficacy exceeds that of the current standard drug for treatment of CCHF, ribavirin.


Asunto(s)
Amidas/farmacología , Antivirales/farmacología , Virus de la Fiebre Hemorrágica de Crimea-Congo/efectos de los fármacos , Fiebre Hemorrágica de Crimea/virología , Indoles/farmacología , Pirazinas/farmacología , Ribavirina/farmacología , Amidas/administración & dosificación , Amidas/uso terapéutico , Amidas/toxicidad , Animales , Antivirales/administración & dosificación , Antivirales/uso terapéutico , Antivirales/toxicidad , Chlorocebus aethiops , Modelos Animales de Enfermedad , Femenino , Fiebre Hemorrágica de Crimea/tratamiento farmacológico , Indoles/administración & dosificación , Indoles/uso terapéutico , Indoles/toxicidad , Hígado/química , Hígado/inmunología , Hígado/patología , Hígado/virología , Masculino , Ratones , Ratones Transgénicos , Pirazinas/administración & dosificación , Pirazinas/uso terapéutico , Pirazinas/toxicidad , Receptor de Interferón alfa y beta/genética , Ribavirina/administración & dosificación , Ribavirina/uso terapéutico , Ribavirina/toxicidad , Células Vero
15.
Arch Virol ; 158(9): 1895-905, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23553456

RESUMEN

The Lassa virus nucleoprotein (NP) is a multifunctional protein that plays an essential role in many aspects of the viral life cycle, including RNA encapsidation, viral transcription and replication, recruitment of ribonucleoprotein complexes to viral budding sites, and inhibition of the host cell interferon response. While it is known that NP is capable of forming oligomers, both the oligomeric state of NP in mammalian cells and the significance of NP oligomerization for its various functions remain unclear. Here, we demonstrate that Lassa virus NP solely forms trimers upon expression in mammalian cells. Using a minigenome assay we show that mutants that are not able to form stable trimers are no longer functional during transcription and/or replication of the minigenome, indicating that NP trimerization is essential for transcription and/or replication of the viral genome. However, mutations leading to destabilization of the NP trimer did not impact the incorporation of NP into virus-like particles or its ability to suppress interferon-induced gene expression, two important functions of arenavirus NP.


Asunto(s)
Arenavirus/metabolismo , Nucleoproteínas/metabolismo , Secuencia de Aminoácidos , Arenavirus/genética , Línea Celular Tumoral , Células HEK293 , Humanos , Virus Lassa/genética , Virus Lassa/metabolismo , Datos de Secuencia Molecular , Nucleoproteínas/química , Nucleoproteínas/genética , Multimerización de Proteína , Proteínas Virales/genética , Proteínas Virales/metabolismo , Replicación Viral
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...