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1.
Nucleic Acids Res ; 52(18): 11317-11335, 2024 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-39193907

RESUMO

In eukaryotic translation initiation, the 48S preinitiation complex (PIC) scans the 5' untranslated region of mRNAs to search for the cognate start codon (AUG) with assistance from various eukaryotic initiation factors (eIFs). Cognate start codon recognition is precise, rejecting near-cognate codons with a single base difference. However, the structural basis of discrimination of near-cognate start codons was not known. We have captured multiple yeast 48S PICs with a near-cognate AUC codon at the P-site, revealing that the AUC codon induces instability in the codon-anticodon at the P-site, leading to a disordered N-terminal tail of eIF1A. Following eIF1 dissociation, the N-terminal domain of eIF5 fails to occupy the vacant eIF1 position, and eIF2ß becomes flexible. Consequently, 48S with an AUC codon is less favourable for initiation. Furthermore, we observe hitherto unreported metastable states of the eIF2-GTP-Met-tRNAMet ternary complex, where the eIF2ß helix-turn-helix domain may facilitate eIF5 association by preventing eIF1 rebinding to 48S PIC. Finally, a swivelled head conformation of 48S PIC appears crucial for discriminating incorrect and selection of the correct codon-anticodon pair during translation initiation.


Assuntos
Códon de Iniciação , Iniciação Traducional da Cadeia Peptídica , Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Códon de Iniciação/genética , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/química , Fatores de Iniciação em Eucariotos/metabolismo , Fatores de Iniciação em Eucariotos/genética , Fatores de Iniciação em Eucariotos/química , Fator de Iniciação 1 em Eucariotos/metabolismo , Fator de Iniciação 1 em Eucariotos/genética , Anticódon/genética , Fator de Iniciação 2 em Eucariotos/metabolismo , Fator de Iniciação 2 em Eucariotos/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Mensageiro/química , Modelos Moleculares , Regiões 5' não Traduzidas
2.
Retina ; 44(9): 1580-1589, 2024 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-39167579

RESUMO

PURPOSE: To determine the association between gene-expression profiling (GEP), next-generation sequencing (NGS), preferentially expressed antigen in melanoma (PRAME) features, and metastatic risk in patients with uveal melanoma (UM). METHODS: A retrospective analysis of patients with UM treated by brachytherapy or enucleation by a single ocular oncologist was conducted from November 2020 and July 2022. Clinicopathologic features, patient outcomes, GEP classification, NGS, and PRAME results were recorded. RESULTS: Comprehensive GEP, PRAME, and NGS testing was performed on 135 UMs. The presence of eukaryotic translation initiation factor 1A, X-chromosomal and splicing factor 3B subunit 1 mutations was significantly associated with GEP class 1A and GEP class 1B, respectively. The presence of BRCA- associated protein-1 mutation was significantly associated with GEP class 2. The average largest basal diameter for tumors with eukaryotic translation initiation factor 1A, X-chromosomal mutations was significantly smaller than those with splicing factor 3B subunit 1 mutations and BRCA1-associated protein-1 mutations. Class 2 tumors metastasized sooner than GEP class 1 tumors. Tumors with splicing factor 3B subunit 1 and/or BRCA1-associated protein-1 mutations metastasized sooner compared with tumors that had either no driver mutation or no mutations at all. Tumors with splicing factor 3B subunit 1 did not have a significantly different time to metastasis compared with tumors with BRCA1-associated protein-1 (P value = 0.97). Forty tumors (30%) were PRAME positive, and the remaining 95 tumors (70%) were PRAME negative. Tumors with PRAME-positive status did not have a significantly different time to metastasis compared with tumors without PRAME-positive status (P value = 0.11). CONCLUSION: GEP, NGS, and PRAME expression analysis help determine different levels of metastatic risk in UM. Although other prognostic tests exist, the following study reports on the use of NGS for metastatic prognostication in UM. However, limitations of NGS exist, especially with small lesions that are technically difficult to biopsy.


Assuntos
Antígenos de Neoplasias , Biomarcadores Tumorais , Perfilação da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Melanoma , Neoplasias Uveais , Humanos , Neoplasias Uveais/genética , Neoplasias Uveais/diagnóstico , Melanoma/genética , Estudos Retrospectivos , Masculino , Feminino , Pessoa de Meia-Idade , Antígenos de Neoplasias/genética , Perfilação da Expressão Gênica/métodos , Idoso , Biomarcadores Tumorais/genética , Mutação , Adulto , Regulação Neoplásica da Expressão Gênica , Idoso de 80 Anos ou mais , Fator de Iniciação 1 em Eucariotos/genética , Fatores de Processamento de RNA/genética , Fatores de Processamento de RNA/metabolismo , Braquiterapia , Fosfoproteínas , Proteínas Supressoras de Tumor , Ubiquitina Tiolesterase
3.
Commun Biol ; 5(1): 587, 2022 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-35705698

RESUMO

Accurate and high-speed scanning and subsequent selection of the correct start codon are important events in protein synthesis. Eukaryotic mRNAs have long 5' UTRs that are inspected for the presence of a start codon by the ribosomal 48S pre-initiation complex (PIC). However, the conformational state of the 48S PIC required for inspecting every codon is not clearly understood. Here, atomistic molecular dynamics (MD) simulations and energy calculations suggest that the scanning conformation of 48S PIC may reject all but 4 (GUG, CUG, UUG and ACG) of the 63 non-AUG codons, and initiation factor eIF1 is crucial for this discrimination. We provide insights into the possible role of initiation factors eIF1, eIF1A, eIF2α and eIF2ß in scanning. Overall, the study highlights how the scanning conformation of ribosomal 48S PIC acts as a coarse selectivity checkpoint for start codon selection and scans long 5' UTRs in eukaryotic mRNAs with accuracy and high speed.


Assuntos
Fator de Iniciação 1 em Eucariotos , Iniciação Traducional da Cadeia Peptídica , Regiões 5' não Traduzidas , Códon de Iniciação/genética , Fator de Iniciação 1 em Eucariotos/genética , Fator de Iniciação 1 em Eucariotos/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
4.
Theriogenology ; 180: 87-93, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-34954662

RESUMO

Long noncoding RNAs (lncRNAs) are abundant in mammalian genomes and have been found to play important roles in many biological events. However, the mechanism by which lncRNAs regulate embryonic development remains to be fully elucidated. Here, we investigated the function of the lncRNA, TCONS_00135926 (referred to as lnc5926), through knockdown and overexpression experiments in goat early embryos. Lnc5926 expression at the eight-cell embryonic stage was significantly higher than that at other stages, which was consistent with the pattern of embryonic genome activation (EGA) gene expression. The blastocyst rate after lnc5926 knockdown in eight-cell embryos was significantly lower than that in the control group (0.2% vs. 17.1%, p < 0.05), whereas the cleavage rate was not affected (71.9% vs. 75.1%, p ˃ 0.05). After knockdown or overexpression of lnc5926 in embryos, we measured expression levels of the potential target genes, STAM, HACD1, UBL5, MIOX, ELF1, and the key EGA genes, ZSCAN4 and EIF1AX. Only ZSCAN4 and EIF1AX were significantly downregulated after lnc5926 knockdown, and this effect was reversed by lnc5926 overexpression. We conclude that lnc5926 plays an essential role in early embryonic development in goats by regulating expression of EGA-associated genes.


Assuntos
Proteínas de Ligação a DNA/genética , Desenvolvimento Embrionário , Fator de Iniciação 1 em Eucariotos/genética , Cabras , RNA Longo não Codificante , Fatores de Transcrição/genética , Animais , Blastocisto , Desenvolvimento Embrionário/genética , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Genoma , Cabras/embriologia , Cabras/genética , Gravidez , RNA Longo não Codificante/genética
5.
Microbiologyopen ; 10(6): e1229, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34964294

RESUMO

The filamentous fungus Magnaporthe oryzae has the potential to be developed as an alternative platform organism for the heterologous production of industrially important enzymes. M. oryzae is easy to handle, fast-growing and unlike yeast, posttranslational modifications like N-glycosylations are similar to the human organism. Here, we established M. oryzae as a host for the expression of the unspecific peroxygenase from the basidiomycete Agrocybe aegerita (AaeUPO). Note, UPOs are attractive biocatalysts for selective oxyfunctionalization of non-activated carbon-hydrogen bonds. To improve and simplify the isolation of AaeUPO in M. oryzae, we fused a Magnaporthe signal peptide for protein secretion and set it under control of the strong EF1α-promoter. The success of the heterologous production of full-length AaeUPO in M. oryzae and the secretion of the functional enzyme was confirmed by a peroxygenase-specific enzyme assay. These results offer the possibility to establish the filamentous ascomycete M. oryzae as a broad applicable alternative expression system.


Assuntos
Agrocybe/enzimologia , Magnaporthe/genética , Oxigenases de Função Mista/biossíntese , Agrocybe/genética , Fator de Iniciação 1 em Eucariotos/genética , Proteínas Fúngicas/biossíntese , Proteínas Fúngicas/genética , Magnaporthe/metabolismo , Oxigenases de Função Mista/genética , Regiões Promotoras Genéticas , Sinais Direcionadores de Proteínas/genética , Proteínas Recombinantes/biossíntese
6.
Ophthalmic Genet ; 42(6): 732-743, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34353217

RESUMO

Uveal melanoma (UM) is the most common primary intraocular malignancy in adults, and its metastases are known to be fatal. It is critical to identify molecular markers to be used in potential prognostic evaluation for early diagnosis, treatment, and metastasis or to investigate all aspects of known genetic anomalies. Therefore, this study aimed to analyze the eight genes (GNAQ, GNA11, BAP1, SF3B1, SRSF2, EIF1AX, PLCB4, and CYSLTR2) that are associated with the most common genetic anomalies in UM from a molecular perspective. The genome sequences and expression profiles of 108 UM patients were obtained via bioinformatics tools that provide data from TCGA. The overall mutational load and the mutation patterns for eight genes, in particular, were thoroughly determined. Moreover, PolyPhen2 and SNAP2 tools were used to estimate the oncogenic/pathogenic properties of identified mutations for UM. In addition to the mutation profile, the effects of the presence of a mutation on gene expression and survival were determined. Finally, STRING network analysis was performed to better understand the functional relationships of mutated proteins in cellular processes. There were 27 missense mutations, 16 frameshift mutations, six nonsense mutations, and three splice region mutations among the 52 mutations found in eight genes, and 26 of them had pathogenic properties. BAP1 m-RNA expression was significantly lower in tumors with the mutant genotype (p = .001). The impact of gene expression, which has poor prognostic importance, on survival is statistically significant for high-expressed BAP1 (p = .0015) and low-expressed CYSLTR2 (p = .0021). To assess the current state of this potentially devastating disease, a molecular perspective has been evaluated. Defining this molecular perspective can be useful in developing targeted drug therapies and personalized medicine.


Assuntos
Proteínas do Olho/genética , Regulação Neoplásica da Expressão Gênica/fisiologia , Melanoma/genética , Mutação/genética , Proteínas de Neoplasias/genética , Neoplasias Uveais/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Biologia Computacional , Análise Mutacional de DNA , Fator de Iniciação 1 em Eucariotos/genética , Feminino , Subunidades alfa de Proteínas de Ligação ao GTP/genética , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/genética , Humanos , Masculino , Melanoma/mortalidade , Melanoma/patologia , Pessoa de Meia-Idade , Fosfolipase C beta/genética , Fosfoproteínas/genética , Fatores de Processamento de RNA/genética , RNA Mensageiro/genética , Receptores de Leucotrienos/genética , Fatores de Processamento de Serina-Arginina/genética , Proteínas Supressoras de Tumor/genética , Ubiquitina Tiolesterase/genética , Neoplasias Uveais/mortalidade , Neoplasias Uveais/patologia , Adulto Jovem
7.
J Mol Histol ; 52(5): 965-973, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34405343

RESUMO

Preimplantation embryo development is characterized by drastic nuclear reprogramming and dynamic stage-specific gene expression. Key regulators of this earliest developmental stage have not been revealed. In the present study, a "non-classical" nuclear-localization pattern of eIF1A was observed during early developmental stages of mouse preimplantation embryo before late-morula. In particular, eIF1A is most highly expressed in the nuclear of 2-cell embryo. Knockdown eIF1A by siRNA microinjection affected the development of mouse preimplantation embryo, resulted in decreased blastocyst formation rate. CDX2 protein expression level significantly down-regulated after eIF1A knockdown in morula stage. In addition, the mRNA expression level of Hsp70.1 was also decreased in 2-cell embryo. The results indicate an indispensable role of eIF1A in mouse preimplantation embryos.


Assuntos
Núcleo Celular/metabolismo , Desenvolvimento Embrionário , Fator de Iniciação 1 em Eucariotos/metabolismo , Animais , Biomarcadores/metabolismo , Fator de Iniciação 1 em Eucariotos/genética , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Técnicas de Silenciamento de Genes , Genoma , Masculino , Camundongos , Fatores de Transcrição/metabolismo , Zigoto/metabolismo
8.
Acta Med Acad ; 50(1): 4-12, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34075760

RESUMO

OBJECTIVE: Mutations in the EIF1AX gene have been recently detected in a small percentage of benign and malignant thyroid lesions. We sought to investigate the prevalence and clinical significance of EIF1AX mutations and co-mutations in cytologically indeterminate thyroid nodules at our institution. MATERIALS AND METHODS: A 5-year retrospective analysis was performed on thyroid nodules with a cytologic diagnosis of Bethesda category III or IV, which had undergone testing by our in-house next generation sequencing panel. Surgically resected nodules with EIF1AX mutations were identified, and mutation type and presence of co-mutations were correlated with histopathologic diagnosis. RESULTS: 41/904 (4.5%) cases overall and 26/229 (11.4%) surgically resected nodules harbored an EIF1AX mutation. The most common histologic diagnoses were follicular thyroid carcinoma and follicular variant of papillary thyroid carcinoma. 11/26 (42.3%) of nodules had isolated EIF1AX mutation. Comutations were found in RAS (12/26; 46.2%), TERT (5/26; 19.2%) and TP53 (2/26; 7.7%). EIF1AX mutation alone conferred a 36.4% risk of malignancy (ROM) and 54.5% ROM or noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP), while the ROM was significantly higher in nodules with concurrent RAS (71.4%), TERT, TP53 and RAS+TERT (100%) mutations. CONCLUSION: EIF1AX mutations occur in benign and malignant follicular thyroid neoplasms. In our cohort, the majority of mutations occurred at the splice acceptor site between exons 5 and 6. Importantly, the coexistence of EIF1AX mutations with other driver pathogenic mutations in RAS, TERT and TP53 conferred a 100% ROM or NIFTP, indicating that such nodules require surgical removal.


Assuntos
Adenocarcinoma Folicular , Fator de Iniciação 1 em Eucariotos , Neoplasias da Glândula Tireoide , Nódulo da Glândula Tireoide , Fator de Iniciação 1 em Eucariotos/genética , Humanos , Mutação , Estudos Retrospectivos , Neoplasias da Glândula Tireoide/genética , Nódulo da Glândula Tireoide/genética
9.
Mol Biol Rep ; 48(2): 1677-1685, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33575959

RESUMO

Quantitative gene expression analysis by qPCR requires reference genes for normalization. Lagerstroemia indica (crape myrtle) is a popular ornamental plant in the world, but suitable endogenous reference genes are lacking. To find suitable reference genes, we evaluated the stabilities of nine candidate genes in six experimental data sets: six different tissues, three leaf colors, nine flower colors, and under three abiotic stresses (salt, drought, cold) using four statistical algorithms. A target gene LiMYB56 (homolog of Arabidopsis MYB56) was used to verify the authenticity and accuracy of the candidate reference genes. The results showed that the combination of two stably expressed reference genes, rather than a single reference gene, improved the accuracy of the qPCR. LiEF1α-2 + LiEF1α-3 was best for the tissue, salt treatment, and drought treatment sets; LiEF1α-2 + LiEF1α-1 was optimal for leaf color; LiEF1α-2 + LiACT7 was optimal for cold treatment; and LiUBC + LiEF1α-1 was best for the flower color set. Notably, LiEF1α-2 had high expression stability in all six experimental sets, implying it may be a good reference gene for expression studies in L. indica. Our results will facilitate future gene expression studies in L. indica.


Assuntos
Flores/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Lagerstroemia/metabolismo , Reação em Cadeia da Polimerase em Tempo Real/métodos , Estresse Fisiológico/genética , Algoritmos , Proteínas de Arabidopsis/genética , Resposta ao Choque Frio/genética , Secas , Fator de Iniciação 1 em Eucariotos/genética , Flores/genética , Perfilação da Expressão Gênica , Genes de Plantas , Lagerstroemia/genética , Especificidade de Órgãos/genética , Folhas de Planta/genética , Folhas de Planta/metabolismo , Estresse Salino/genética , Sensibilidade e Especificidade , Cloreto de Sódio/farmacologia , Fatores de Transcrição/genética
10.
Bull Exp Biol Med ; 169(5): 669-672, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32990852

RESUMO

The feasibility of using molecular genetic markers associated with thyroid neoplasms and more aggressive course of the disease is now actively studied. We analyzed the diagnostic value of somatic mutations in the hot spots of BRAF, KRAS, KRAS, EIF1AX, and TERT genes in histological material from 153 patients with thyroid gland neoplasms. BRAF mutations (exon 15, codon area 600-601) were found in 54 patients, NRAS mutations (exon 3, codon 61) were detected in 12 patients; mutations KRAS, TERT, and EIF1AX genes were not detected.


Assuntos
Códon/genética , Fator de Iniciação 1 em Eucariotos/genética , Éxons/genética , GTP Fosfo-Hidrolases/genética , Proteínas de Membrana/genética , Mutação/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Telomerase/genética , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/patologia , Humanos , Proteínas Proto-Oncogênicas B-raf/genética
11.
Cell Prolif ; 53(10): e12903, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32926483

RESUMO

OBJECTIVE: Dysregulation of the cell cycle is associated with the progression of malignant cancer, but its precise functional contribution is unknown. MATERIALS AND METHODS: The expression of EIF1AX in breast cancer tissues was detected by qRT-PCR and immunohistochemistry staining. Colony formation and tumour xenograft assays were used to examine the tumorigenesis-associated function of EIF1AX in vitro and in vivo. RNA-Seq analysis was used to select the downstream target genes of EIF1AX. Flow cytometry, ChIP and luciferase assays were used to investigate the molecular mechanisms by which EIF1AX regulates p21 in breast cancer cells. RESULTS: EIF1AX promoted breast cancer cell proliferation by promoting the G1/S cell cycle transition. A mechanistic investigation showed that EIF1AX inhibited the expression of p21, which is an essential cell cycle regulator. We identified that the transcriptional regulation of p21 by EIF1AX was p53-independent. Clinically, EIF1AX levels were significantly elevated in breast cancer tissues, and the high level of EIF1AX was associated with lower survival rates in breast cancer patients. CONCLUSIONS: Our results imply that EIF1AX may play a key role in the incidence and promotion of breast cancer and may, thus, serve as a valuable target for breast cancer therapy.


Assuntos
Neoplasias da Mama/patologia , Proliferação de Células , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Fator de Iniciação 1 em Eucariotos/metabolismo , Animais , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Inibidor de Quinase Dependente de Ciclina p21/genética , Fator de Iniciação 1 em Eucariotos/antagonistas & inibidores , Fator de Iniciação 1 em Eucariotos/genética , Feminino , Fase G1 , Humanos , Camundongos , Camundongos Nus , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Fase S , Ativação Transcricional , Proteína Supressora de Tumor p53/metabolismo , Regulação para Cima , Ensaios Antitumorais Modelo de Xenoenxerto
12.
Gene ; 758: 144958, 2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-32683073

RESUMO

Short-lived therapeutic gene expression in mammalian cells by DNA methylation is one of the major challenges in gene therapy. In this study, we assessed the implication of DNA methylation on the duration of GFP expression in mouse embryonic stem (ES) and mouse induced pluripotent stem (iPS) cells. The cells were transduced with lentivirus (LV) carrying green fluorescent protein (GFP) driven by either human elongation factor (EF1α) or cytomegalovirus (CMV) promoter. Transduced iPS cells exhibited higher percentage of GFP+ cells with persistent mean fluorescent intensity than transduced ES cells. Analysis on the integrated copy of transgene in the population of the transduced cells demonstrated similar copy number. However, significant increase in GFP intensity following 5-azaC treatment was observed in transduced ES cells only, suggesting the influence of DNA methylation in transgene silencing. Subsequent DNA methylation analysis showed that the promoter and the GFP region of the provirus in iPS cells had negligible methylation profile compared to transduced ES cells. Interestingly, sustained transgene expression was observed upon directed differentiation of transduced iPS cells towards CD34+ CD45+ cells. Hence, this study has shown that favourable transgene activity from lentiviral transduced iPS cells was due to the lack of methylation at the proviral regions.


Assuntos
Metilação de DNA/genética , Células-Tronco Embrionárias/metabolismo , Proteínas de Fluorescência Verde/genética , Células-Tronco Pluripotentes Induzidas/metabolismo , Animais , Azacitidina/farmacologia , Linhagem Celular , Citomegalovirus/genética , Fator de Iniciação 1 em Eucariotos/genética , Regulação da Expressão Gênica/genética , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Regiões Promotoras Genéticas/genética , Transdução Genética
13.
J Virol Methods ; 284: 113923, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32615131

RESUMO

Ovine pulmonary adenocarcinoma (OPA) is a globally occurring tumor of lung epithelium which seriously affects the development of sheep farming. In our research, lung tissues of 3 naturally infected OPA individuals and 3 healthy individuals (2-4 years old) were collected. RNA was extracted for transcriptome analysis and reference gene selection. According to transcriptome analysis, 7 candidate reference genes (eukaryotic translation initiation factor 1, EIF1; glyceraldehyde-3-phosphate dehydrogenase, GAPDH; beta-actin, ACTB; GABA Type A receptor-associated protein, GABARAP; activating transcription factor 4, ATF4; ribosomal protein S15, RPS15; and Y-Box binding protein 1, YBX1) showed fragments per kilobase of transcript per million fragments mapped (FPKM) values > 200.0 and standard errors of the means (SEM) < 20.0. Expression of the above candidate reference genes was evaluated by Real-time quantitative polymerase chain reaction (RT-qPCR) combined with the analysis using GeNorm, NormFinder, and BestKeeper software. Comprehensive analysis of the results showed that ACTB was the most stable one, followed by EIF1 and GABARAP. Then, expression stability of the above three genes were validated, suggesting as suitable reference genes in sheep lung tissue, in additional 30 OPA-affected lung tissues and 10 healthy ovine lung tissues. Finally, our findings will be helpful for the subsequent study on the tumorigenic mechanism of OPA.


Assuntos
Perfilação da Expressão Gênica/normas , Pulmão/metabolismo , Adenomatose Pulmonar Ovina/metabolismo , Actinas/genética , Animais , Fator de Iniciação 1 em Eucariotos/genética , Feminino , Perfilação da Expressão Gênica/métodos , Retrovirus Jaagsiekte de Ovinos , Pulmão/patologia , Proteínas Associadas aos Microtúbulos/genética , Adenomatose Pulmonar Ovina/genética , Adenomatose Pulmonar Ovina/patologia , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Padrões de Referência , Reprodutibilidade dos Testes , Análise de Sequência de RNA , Ovinos
14.
Cell Rep ; 31(1): 107497, 2020 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-32268096

RESUMO

In higher eukaryotes, the mRNA sequence in the direct vicinity of the start codon, called the Kozak sequence (CRCCaugG, where R is a purine), is known to influence the rate of the initiation process. However, the molecular basis underlying its role remains poorly understood. Here, we present the cryoelectron microscopy (cryo-EM) structures of mammalian late-stage 48S initiation complexes (LS48S ICs) in the presence of two different native mRNA sequences, ß-globin and histone 4, at overall resolution of 3 and 3.5 Å, respectively. Our high-resolution structures unravel key interactions from the mRNA to eukaryotic initiation factors (eIFs): 1A, 2, 3, 18S rRNA, and several 40S ribosomal proteins. In addition, we are able to study the structural role of ABCE1 in the formation of native 48S ICs. Our results reveal a comprehensive map of ribosome/eIF-mRNA and ribosome/eIF-tRNA interactions and suggest the impact of mRNA sequence on the structure of the LS48S IC.


Assuntos
Fatores de Iniciação em Eucariotos/metabolismo , Fatores de Iniciação em Eucariotos/ultraestrutura , Iniciação da Transcrição Genética/fisiologia , Transportadores de Cassetes de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/metabolismo , Animais , Códon de Iniciação/genética , Códon de Iniciação/ultraestrutura , Microscopia Crioeletrônica/métodos , Elementos Facilitadores Genéticos/genética , Fator de Iniciação 1 em Eucariotos/genética , Fator de Iniciação 1 em Eucariotos/metabolismo , Fator de Iniciação 2 em Eucariotos/genética , Fator de Iniciação 2 em Eucariotos/metabolismo , Fator de Iniciação 3 em Eucariotos/genética , Fator de Iniciação 3 em Eucariotos/metabolismo , Humanos , Camundongos , Iniciação Traducional da Cadeia Peptídica , Biossíntese de Proteínas , RNA Mensageiro/metabolismo , RNA Ribossômico 18S/genética , RNA Ribossômico 18S/metabolismo , RNA de Transferência/metabolismo , Proteínas Ribossômicas/metabolismo , Ribossomos/metabolismo , Globinas beta/genética , Globinas beta/ultraestrutura
15.
Arch Endocrinol Metab ; 64(2): 185-189, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32236306

RESUMO

The EIF1AX gene mutations have been recently associated with papillary thyroid carcinoma and anaplastic thyroid cancer. According with these reports, the gene as been considered as a drive gene for thyroid cancer development. However, the occurrence of these alterations in benign thyroid lesions is not known and is still under investigation. Some authors have already reported the presence of EIF1AX variants in follicular adenomas and hyperplastic nodules. Here, we describe for the first time a case of a man with the EIF1AX c.338-2A>T splice site mutation in an indeterminate FNA lesion with trabecular adenoma at final histology in the absence of other pathogenetic mutations, demonstrating that further studies are required to better understand EIF1AX role in the tumorigenesis of thyroid carcinoma.


Assuntos
Adenoma/diagnóstico , Adenoma/genética , Fator de Iniciação 1 em Eucariotos/genética , Mutação/genética , Neoplasias da Glândula Tireoide/diagnóstico , Neoplasias da Glândula Tireoide/genética , Biópsia por Agulha Fina , Humanos , Masculino , Pessoa de Meia-Idade
16.
Arch. endocrinol. metab. (Online) ; 64(2): 185-189, Mar.-Apr. 2020. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1131063

RESUMO

SUMMARY The EIF1AX gene mutations have been recently associated with papillary thyroid carcinoma and anaplastic thyroid cancer. According with these reports, the gene as been considered as a drive gene for thyroid cancer development. However, the occurrence of these alterations in benign thyroid lesions is not known and is still under investigation. Some authors have already reported the presence of EIF1AX variants in follicular adenomas and hyperplastic nodules. Here, we describe for the first time a case of a man with the EIF1AX c.338-2A>T splice site mutation in an indeterminate FNA lesion with trabecular adenoma at final histology in the absence of other pathogenetic mutations, demonstrating that further studies are required to better understand EIF1AX role in the tumorigenesis of thyroid carcinoma.


Assuntos
Humanos , Masculino , Neoplasias da Glândula Tireoide/diagnóstico , Neoplasias da Glândula Tireoide/genética , Adenoma/diagnóstico , Adenoma/genética , Fator de Iniciação 1 em Eucariotos/genética , Mutação/genética , Biópsia por Agulha Fina , Pessoa de Meia-Idade
17.
Ophthalmic Res ; 63(3): 358-368, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31614358

RESUMO

BACKGROUND: The purpose of this study is to determine the mutation frequencies of key driver genes in uveal melanoma (UM) in Chinese patients and to detect associations between metastasis and the mutation of these genes. METHOD: A total of 85 patients with UM were enrolled in this study, including 18 patients with metastasis and 67 without metastasis. Sanger sequencing covering the mutational hotspot regions of the G protein subunit alpha Q (GNAQ), GNA11, splicing factor 3B subunit 1 (SF3B1), X-linked eukaryotic translation initiation factor 1A (EIF1AX), phospholipase C beta 4 (PLCB4) and cysteinyl leukotriene receptor 2 (CYSLTR2) genes was used to analyse the mutations in Chinese patients. RESULTS: The frequencies of GNAQ and GNA11 mutations in UM were 45% (38/85) and 35% (30/85) respectively. The frequencies of SF3B1 and EIF1AX mutations were 37% (31/85) and 9% (8/85) respectively. Only 2 mutations were detected in exon 4 of GNAQ, and no mutations were detected in exon 4 of GNA11. A novel mutation, c.627G>T (Q209H) in GNA11 was found. The detected mutations affecting SF3B1 were c.1873C>T (R625C), c.1874G>A (R625H) and c.1874G>T (R625L). The association between the mutations in SF3B1 and low risk of metastasis was statistically significant (OR 0.17, 95% CI 0.035-0.819). The mutations affecting EIF1AX were -23G>A (5'-UTR), c.5C>G (P2R), c.23G>A (G8Q), c.25G>C (G9A) and c.38_39GC>CT (R13P). No mutations were found in the PLCB4 and CYSLTR2 genes. Unfortunately, information on BRCA1-associated protein 1 could not be obtained. CONCLUSIONS: These data indicate that mutations in the PLCB4 and CYSLTR2 genes are rare in Chinese UM patients. The mutations in GNAQ, GNA11 and EIF1AX were not associated with metastasis, whereas SF3B1 mutations were correlated with low risk of metastasis and demonstrated a protective effect in UM patients in China.


Assuntos
Fator de Iniciação 1 em Eucariotos/genética , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/genética , Melanoma/genética , Mutação , Fosfolipase C beta/genética , Fosfoproteínas/genética , Fatores de Processamento de RNA/genética , Receptores de Leucotrienos/genética , Neoplasias Uveais/genética , Adolescente , Adulto , Idoso , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Análise Mutacional de DNA , DNA de Neoplasias/genética , Fator de Iniciação 1 em Eucariotos/metabolismo , Neoplasias Oculares/diagnóstico , Neoplasias Oculares/genética , Neoplasias Oculares/metabolismo , Feminino , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/metabolismo , Humanos , Masculino , Melanoma/diagnóstico , Melanoma/metabolismo , Pessoa de Meia-Idade , Fosfolipase C beta/metabolismo , Fosfoproteínas/metabolismo , Fatores de Processamento de RNA/metabolismo , Receptores de Leucotrienos/metabolismo , Estudos Retrospectivos , Neoplasias Uveais/diagnóstico , Neoplasias Uveais/metabolismo , Adulto Jovem
18.
J Photochem Photobiol B ; 202: 111720, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31841988

RESUMO

It has been widely reported that ultraviolet-B (UV-B) radiation is the main extrinsic etiological agent that causes skin photodamage. UV-B exposure mediated photodamage (photo-aging/photo-carcinogenesis) to human skin is caused due to several physiological events at tissue, cellular and molecular levels that lead to impairment of skin function and integrity. In the present study, we investigated the protective role of Trigonelline (TG) against UV-B induced photo-damage in Human Dermal Fibroblasts (Hs68 cells) and Balb/C mice. We exposed human skin fibroblasts and Balb/C mice to UV-B radiation and evaluated various parameters of cellular damage, including, oxidative stress, cytosolic calcium (Ca2+) levels, apoptotic and ER-stress marker proteins. We found that UV-B irradiation induced ROS generation lead to the depletion of endoplasmic reticulum (ER) calcium and increased the expression of ER stress protein markers (phosphorylated elf2α, CHOP, ATF4) as well as apoptotic protein markers (Bcl2, Bax and caspase-9) in a dose and time dependent manner in Hs68 cells. We then determined the effect of TG treatment on UV-B -induced cell death in Hs68 cells and observed that cells exposed to UV-B radiation and treated with TG had a significantly higher survival rate compared to cells exposed to UV-B radiation alone. TG treatment successfully reduced oxidative stress; restored Ca2+ homeostasis and re-established the ER function and prevented apoptotic cell death process. Our results suggest that TG can be used as a potential therapeutic/cosmeceutic agent in preventing skin photo-damage.


Assuntos
Alcaloides/farmacologia , Apoptose/efeitos dos fármacos , Cálcio/metabolismo , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Raios Ultravioleta , Animais , Apoptose/efeitos da radiação , Caspase 9/genética , Caspase 9/metabolismo , Linhagem Celular , Retículo Endoplasmático/metabolismo , Estresse do Retículo Endoplasmático/efeitos da radiação , Fator de Iniciação 1 em Eucariotos/genética , Fator de Iniciação 1 em Eucariotos/metabolismo , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Fibroblastos/efeitos da radiação , Expressão Gênica/efeitos dos fármacos , Expressão Gênica/efeitos da radiação , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Estresse Oxidativo/efeitos da radiação , Espécies Reativas de Oxigênio/metabolismo , Fator de Transcrição CHOP/genética , Fator de Transcrição CHOP/metabolismo
19.
Microb Pathog ; 137: 103783, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31600536

RESUMO

The laboratorial diagnosis of leishmaniasis is based on parasitological methods, which are invasive, present high cost, require laboratorial infrastructure and/or trained professionals; as well as by immunological methods, which usually present variable sensitivity and/or specificity, such as when they are applied to identify asymptomatic cases and/or mammalian hosts presenting low levels of antileishmanial antibodies. As consequence, new studies aiming to identify more refined antigens to diagnose visceral (VL) and tegumentary (TL) leishmaniasis are urgently necessary. In the present work, the Leishmania eukaryotic elongation factor-1 beta (EF1b) protein, which was identified in L. infantum protein extracts by antibodies in VL patients' sera, was cloned and its recombinant version (rEF1b) was expressed, purified and tested as a diagnostic marker for VL and TL. The post-therapeutic serological follow-up was also evaluated in treated and untreated VL and TL patients, when anti-rEF1b antibody levels were measured before and after treatment. Results showed that rEF1b was highly sensitive and specific to diagnose symptomatic and asymptomatic canine VL, as well as human TL and VL. In addition, low cross-reactivity was observed when sera from healthy subjects or leishmaniasis-related diseases patients were tested. The serological follow-up showed also that rEF1b-specific antibodies declined significantly after treatment, suggesting that this protein could be also evaluated as a prognostic marker for human leishmaniasis.


Assuntos
Doenças do Cão/parasitologia , Fator de Iniciação 1 em Eucariotos/imunologia , Leishmania infantum/imunologia , Leishmaniose Visceral/parasitologia , Leishmaniose Visceral/veterinária , Proteínas de Protozoários/imunologia , Adulto , Animais , Anticorpos Antiprotozoários/imunologia , Antígenos de Protozoários/genética , Antígenos de Protozoários/imunologia , Reações Cruzadas , Doenças do Cão/diagnóstico , Doenças do Cão/imunologia , Cães , Ensaio de Imunoadsorção Enzimática , Fator de Iniciação 1 em Eucariotos/genética , Feminino , Humanos , Leishmania infantum/genética , Leishmania infantum/isolamento & purificação , Leishmaniose/diagnóstico , Leishmaniose/imunologia , Leishmaniose/parasitologia , Leishmaniose/veterinária , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/imunologia , Masculino , Pessoa de Meia-Idade , Proteínas de Protozoários/genética , Testes Sorológicos
20.
Invest Ophthalmol Vis Sci ; 60(10): 3595-3605, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31425584

RESUMO

Purpose: Uveal melanoma (UM) is characterized by multiple chromosomal rearrangements and recurrent mutated genes. The aim of this study was to investigate if copy number variations (CNV) alone and in combination with other genetic and clinico-histopathological variables can be used to stratify for disease-free survival (DFS) in enucleated patients with UM. Methods: We analyzed single nucleotide polymorphisms (SNP) array data of primary tumors and other clinical variables of 214 UM patients from the Rotterdam Ocular Melanoma Study (ROMS) cohort. Nonweighted hierarchical clustering of SNP array data was used to identify molecular subclasses with distinct CNV patterns. The subclasses associate with mutational status of BAP1, SF3B1, or EIF1AX. Cox proportional hazard models were then used to study the predictive performance of SNP array cluster-, mutation-, and clinico-histopathological data, and their combination for study endpoint risk. Results: Five clusters with distinct CNV patterns and concomitant mutations in BAP1, SF3B1, or EIF1AX were identified. The sample's cluster allocation contributed significantly to mutational status of samples in predicting the incidence of metastasis during a median of 45.6 (interquartile range [IQR]: 24.7-81.8) months of follow-up (P < 0.05) and vice versa. Furthermore, incorporating all data sources in one model yielded a 0.797 C-score during 100 months of follow-up. Conclusions: UM has distinct CNV patterns that correspond to different mutated driver genes. Incorporating clinico-histopathological, cluster and mutation data in the analysis results in good performance for UM-related DFS prediction.


Assuntos
Fator de Iniciação 1 em Eucariotos/genética , Enucleação Ocular , Melanoma/genética , Melanoma/cirurgia , Fosfoproteínas/genética , Polimorfismo de Nucleotídeo Único , Fatores de Processamento de RNA/genética , Proteínas Supressoras de Tumor/genética , Ubiquitina Tiolesterase/genética , Neoplasias Uveais/genética , Neoplasias Uveais/cirurgia , Idoso , Variações do Número de Cópias de DNA , DNA de Neoplasias/genética , Intervalo Livre de Doença , Feminino , Humanos , Masculino , Melanoma/diagnóstico , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Neoplasias Uveais/diagnóstico
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