RESUMO
To characterize the structure and function of ribosomal protein S13 (RPS13), we identified fulllength open reading frames (ORFs) of three RPS13 genes (RPS13-1, RPS13-2, and RPS13-3) of the Chinese medicinal plant, Sophora flavescens. The target genes were amplified by reverse transcription-olymerase chain reaction (RT-PCR), ligated into the pET22b(+) vector, and then transformed into Escherichia coli BL21 competent cells for protein expression. The physicochemical properties, protein motif, evolution, and structural organization of the three RPS13 genes were analyzed using bioinformatics tools. The full-length ORFs (453 bp) of the three RPS13 genes of S. flavescens were cloned, and each encodes a protein of 151 amino acids in length, and their expression was detected by Western blotting. Bioinformatics analysis showed that RPS13s are stable proteins that are closely related to the 40S RPS13s of Vigna radiate var. radiate. Their three-dimensional structures included three -helices at the C-terminal and four -helices at the N-terminal, and the two clusters of helices were connected by a long random coil, which may help maintain the dynamic bridging interactions between the large and small subunits of the ribosome. The full-length ORFs of three RPS13 genes of S. flavescens were successfully cloned and expressed in vitro. The study of the physicochemical properties, evolution, and secondary and three-dimensional structures of the three proteins will provide the theoretical basis for further studies on the function of RPS13s in plants.
Objetivo: Para caracterizar a estrutura e a função da proteína ribossomal S13 (RPS13), identificamos fases de leitura abertas (ORFs) completas de três genes RPS13 (RPS13-1, RPS13-2 e RPS13-3) da planta medicinal chinesa, Sophora flavescens. Métodos: Os genes alvo foram amplificados por reação em cadeia da polimerase por transcrição reversa (RT-PCR), ligados ao vetor pET22b(+), e então transformados em células competentes de Escherichia coli BL21 para expressão protéica. As propriedades físico-químicas, o motivo protéico, a evolução e a organização estrutural dos três genes RPS13 foram analisados utilizando ferramentas de bioinformática. Resultados: ORFs completos (453 pb) dos três genes RPS13 de S. flavescens foram clonados, e cada um codifica uma proteína de 151 aminoácidos de comprimento, e sua expressão foi detectada por western blotting. A análise de bioinformática mostrou que as RPS13s são proteínas estáveis que estão intimamente relacionadas com as 40S RPS13s de Vigna radiata var. radiate. Suas estruturas tridimensionais incluíam três -hélices no C-terminal e quatro -hélices no N-terminal, e os dois aglomerados de hélices eram conectados por uma longa bobina aleatória, o que pode ajudar a manter as interações de ponte dinâmicas entre o subunidades grandes e pequenas do ribossomo. Conclusões: As ORFs completas de três genes RPS13 de S. flavescens foram clonadas e expressas com sucesso in vitro. O estudo das propriedades físico-químicas, evolução e estruturas secundárias e tridimensionais das três proteínas fornecerão a base teórica para estudos adicionais sobre a função das RPS13s em plantas.
Assuntos
Biologia Computacional , Sophora , Transcrição Reversa , Escherichia coli , GenesRESUMO
INTRODUCTION AND AIM: Hepatitis B virus (HBV) infection remains a public health problem worldwide. In addition, HBV infection results are influenced by various virological, immunological, and genetic factors. Inducible T-cell costimulator (ICOS) polymorphisms involving chronic HBV infection have been confirmed in previous studies. This study was to explore the effects of ICOS single nucleotide polymorphisms in HBV subtypes and their interactions with viral mutations on HBV infection outcomes. MATERIAL AND METHODS: A total of 1,636 Han Chinese individuals were recruited, including 47 asymptomatic HBV carriers (ASC), 353 chronic hepatitis B (CHB) patients, 327 HBV-related liver cirrhosis (LC) patients, 193 HBV-related hepatocellular carcinoma (HCC) patients, 464 patients with spontaneous recovery from HBV infection (SR), and 252 healthy controls (HC). DNA samples from these subjects were genotyped for four ICOS SNPs (rs11883722, rs10932029, rs1559931, and rs4675379). Direct sequencing was used to determine the HBV mutations in the enhancer II, basal core promoter, and pre-core regions. RESULTS: We found that the genotype "TC" of ICOS rs10932029 SNP was associated with decreased HBV-related LC risk in the genotype C group. Additionally, the A1762T, G1764A and A1762T/G1764A mutations were associated with an increased risk of LC in the genotype C group. Further study indicated that interactions between ICOS rs10932029 genotype "TC" and A1762T or A1762T/G1764A mutations significantly decreased the LC risk in the genotype C group. CONCLUSION: The rs10932029 genotype "TC" might be an LC-protective factor for HBV genotype C infection. The interactions between the rs10932029 genotype "TC" and A1762T or A1762T/G1764A mutations could decrease the risk of LC.
Assuntos
DNA Viral/genética , Vírus da Hepatite B/genética , Hepatite B Crônica/genética , Hepatite B Crônica/virologia , Proteína Coestimuladora de Linfócitos T Induzíveis/genética , Mutação , Polimorfismo de Nucleotídeo Único , Adulto , Idoso , Povo Asiático/genética , Carcinoma Hepatocelular/etnologia , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/virologia , Estudos de Casos e Controles , China/epidemiologia , Estudos Transversais , Feminino , Predisposição Genética para Doença , Hepatite B Crônica/diagnóstico , Hepatite B Crônica/etnologia , Interações Hospedeiro-Patógeno , Humanos , Cirrose Hepática/etnologia , Cirrose Hepática/genética , Cirrose Hepática/virologia , Neoplasias Hepáticas/etnologia , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/virologia , Masculino , Pessoa de Meia-Idade , Fenótipo , Prognóstico , Fatores de Proteção , Fatores de RiscoRESUMO
BACKGROUND AND AIM: The HBV covalently closed circular DNA (cccDNA) is organized into a minichromosome in the nuclei of infected hepatocytes through interactions with histone and nonhistone proteins. Retinoid X receptor α (RXRα), a liver-enriched nuclear receptor, participates in regulation of HBV replication and transcription through modulation of HBV enhancer 1 and core promoter activity. MATERIAL AND METHODS: This study investigated RXRα involvement in HBV cccDNA epigenetic modifications. Quantitative cccDNA chromatin immunoprecipitation (ChIP) was applied to study the recruitment of RXRα, histones, and chromatin-modifying enzymes to HBV minichromosome in HepG2 cells after transfection of the linear HBV genome. RESULTS: RXRα Was found to directly bind to HBV cccDNA; recruitment of RXRα to HBV mini-chromosome paralleled HBV replication, histone recruitment, and histone acetylation in HBVcccDNA. Moreover, RXRα overexpression or knock-down significantly increased or impaired the recruitment of the p300 acetyltransferase to cccDNAminichromosome. CONCLUSIONS: Our results confirmed the regulation of RXRα on HBV replication in vitro and demonstrated the modulation of RXRα on HBV cccDNA epigenetics. These findings provide a profound theoretical and experimental basis for late-model antiviral treatment acting on the HBV cccDNA and minichromosome.