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1.
Zhejiang Da Xue Xue Bao Yi Xue Ban ; 53(2): 184-193, 2024 Apr 25.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-38562030

RESUMO

OBJECTIVES: To investigate the role of m.4435A>G and YARS2 c.572G>T (p.G191V) mutations in the development of essential hypertension. METHODS: A hypertensive patient with m.4435A>G and YARS2 p.G191V mutations was identified from previously collected mitochondrial genome and exon sequencing data. Clinical data were collected, and a molecular genetic study was conducted in the proband and his family members. Peripheral venous blood was collected, and immortalized lymphocyte lines constructed. The mitochondrial transfer RNA (tRNA), mitochondrial protein, adenosine triphosphate (ATP), mitochondrial membrane potential (MMP), and reactive oxygen species (ROS) in the constructed lymphocyte cell lines were measured. RESULTS: Mitochondrial genome sequencing showed that all maternal members carried a highly conserved m.4435A>G mutation. The m.4435A>G mutation might affect the secondary structure and folding free energy of mitochondrial tRNA and change its stability, which may influence the anticodon ring structure. Compared with the control group, the cell lines carrying m.4435A>G and YARS2 p.G191V mutations had decreased mitochondrial tRNA homeostasis, mitochondrial protein expression, ATP production and MMP levels, as well as increased ROS levels (all P<0.05). CONCLUSIONS: The YARS2 p.G191V mutation aggravates the changes in mitochondrial translation and mitochondrial function caused by m.4435A>G through affecting the steady-state level of mitochondrial tRNA and further leads to cell dysfunction, indicating that YARS2 p.G191V and m.4435A>G mutations have a synergistic effect in this family and jointly participate in the occurrence and development of essential hypertension.


Assuntos
Hipertensão Essencial , Mutação , RNA de Transferência de Metionina , Tirosina-tRNA Ligase , Feminino , Humanos , Masculino , Hipertensão Essencial/genética , Genoma Mitocondrial , Potencial da Membrana Mitocondrial/genética , Mitocôndrias/genética , Espécies Reativas de Oxigênio/metabolismo , RNA de Transferência/genética , RNA de Transferência de Metionina/genética , Tirosina-tRNA Ligase/genética
2.
Nat Commun ; 14(1): 999, 2023 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-36890170

RESUMO

Dominant mutations in tyrosyl-tRNA synthetase (YARS1) and six other tRNA ligases cause Charcot-Marie-Tooth peripheral neuropathy (CMT). Loss of aminoacylation is not required for their pathogenicity, suggesting a gain-of-function disease mechanism. By an unbiased genetic screen in Drosophila, we link YARS1 dysfunction to actin cytoskeleton organization. Biochemical studies uncover yet unknown actin-bundling property of YARS1 to be enhanced by a CMT mutation, leading to actin disorganization in the Drosophila nervous system, human SH-SY5Y neuroblastoma cells, and patient-derived fibroblasts. Genetic modulation of F-actin organization improves hallmark electrophysiological and morphological features in neurons of flies expressing CMT-causing YARS1 mutations. Similar beneficial effects are observed in flies expressing a neuropathy-causing glycyl-tRNA synthetase. Hence, in this work, we show that YARS1 is an evolutionary-conserved F-actin organizer which links the actin cytoskeleton to tRNA-synthetase-induced neurodegeneration.


Assuntos
Actinas , Tirosina-tRNA Ligase , Animais , Humanos , Actinas/metabolismo , Doença de Charcot-Marie-Tooth/genética , Drosophila/genética , Glicina-tRNA Ligase/genética , Mutação , RNA de Transferência , Tirosina-tRNA Ligase/genética , Tirosina-tRNA Ligase/metabolismo , Linhagem Celular Tumoral
3.
Cancer Biol Ther ; 23(1): 1-8, 2022 12 31.
Artigo em Inglês | MEDLINE | ID: mdl-36154909

RESUMO

Defects in tRNA expressions and modifications had been linked to various types of tumorigenesis and progression in recent studies, including colorectal cancer. In the present study, we evaluated transcript levels of mitochondrial tyrosyl-tRNA synthetase YARS2 in both colorectal cancer tissues and normal colorectal tissues using qRT-PCR. The results revealed that the mRNA expression level of YARS2 in colorectal cancer tissues was significantly higher than those in normal intestinal tissues. Knockdown of YARS2 in human colon cancer cell-line SW620 leads to significant inhibition of cell proliferation and migration. The steady-state level of tRNATyr, OCR, and ATP synthesis were decreased in the YARS2 knockdown cells. Moreover, our data indicated that inhibition of YARS2 is associated with increased reactive oxygen species levels which sensitize these cells to 5-FU treatment. In conclusion, our study revealed that targeting YARS2 could inhibit colorectal cancer progression. Thus, YARS2 might be a carcinogenesis candidate gene and can serve as a potential target for clinical therapy.


Assuntos
Neoplasias Colorretais , Tirosina-tRNA Ligase , Trifosfato de Adenosina , Linhagem Celular Tumoral , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Fluoruracila , Humanos , Mutação , RNA Mensageiro , RNA de Transferência de Tirosina , Espécies Reativas de Oxigênio , Tirosina-tRNA Ligase/genética , Tirosina-tRNA Ligase/metabolismo
4.
J Gastrointestin Liver Dis ; 31(1): 48-59, 2022 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-35306563

RESUMO

BACKGROUND: Hepatocellular carcinoma (HCC) is frequently diagnosed at late stages when curative treatments are no more appliable. Many studies have proved the active role of long non-coding RNAs (lncRNAs) in cancers' biology; here, the functional role of lncRNA NCK1-AS1 in HCC was identified. METHODS: Gene expression in tumor tissues of HCC was evaluated by examining online databases and 88 collected HCC samples from our hospital. The interactions of miR-22-3p with NCK1-AS1 and tyrosyl-tRNA synthetase (YARS) were tested by conducting bioinformatics analysis, luciferase report, and RNA pulldown experiments. CCK-8, colony formation, flow cytometry, wound healing, transwell experiments were used to dissect the role of the NCK1-AS1/miR-22-3p/YARS axis in HCC. RESULTS: NCK1-AS1 was overexpressed in HCC cells and tissues. Functional assays depicted that depletion of NCK1-AS1 hampered malignant character of HCC cells. NCK1-AS1 controlled the availability of miR-22-3p, resulting in YARS upregulation. YARS was found to have a clinical value for HCC diagnosis. Moreover, rescue experiments revealed that miR-22-3p inhibition or YARS overexpression partially blocked the function of NCK1-AS1 deficiency in HCC cells. As for the downstream signaling pathway, we discovered that NCK1-AS1 activated PI3K/AKT signaling by the miR-22-3p/YARS axis. CONCLUSION: The present study verified that NCK1-AS1 could promote HCC progression via the miR-22-3p/YARS axis to activate PI3K/AKT signaling.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , MicroRNAs , RNA Longo não Codificante , Tirosina-tRNA Ligase , Proteínas Adaptadoras de Transdução de Sinal , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Hepáticas/patologia , MicroRNAs/genética , MicroRNAs/metabolismo , Proteínas Oncogênicas , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Longo não Codificante/genética , Transdução de Sinais , Tirosina-tRNA Ligase/genética , Tirosina-tRNA Ligase/metabolismo
5.
Eur J Med Genet ; 64(10): 104294, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34352414

RESUMO

Cytoplasmic aminoacyl-tRNA synthetases (ARSs) are emerging as a cause of numerous rare inherited diseases. Recently, biallelic variants in tyrosyl-tRNA synthetase 1 (YARS1) have been described in ten patients of three families with multi-systemic disease (failure to thrive, developmental delay, liver dysfunction, and lung cysts). Here, we report an additional subject with overlapping clinical findings, heterozygous for two novel variants in tyrosyl-tRNA synthetase 1 (NM_003680.3(YARS1):c.176T>C; p.(Ile59Thr) and NM_003680.3(YARS1):c.237C>G; p.(Tyr79*) identified by whole exome sequencing. The p.Ile59Thr variant is located in the highly conserved aminoacylation domain of the protein. Compared to subjects previously described, this patient presents a much more severe condition. Our findings support implication of two novel YARS1 variants in these disorders. Furthermore, we provide evidence for a reduced protein abundance in cells of the patient, in favor of a partial loss-of-function mechanism.


Assuntos
Deficiências do Desenvolvimento/genética , Insuficiência de Crescimento/genética , Hepatopatias/genética , Pneumopatias/genética , Tirosina-tRNA Ligase/genética , Deficiências do Desenvolvimento/patologia , Insuficiência de Crescimento/patologia , Feminino , Humanos , Lactente , Hepatopatias/patologia , Mutação com Perda de Função , Pneumopatias/patologia
6.
Nucleic Acids Res ; 49(9): 5202-5215, 2021 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-34009360

RESUMO

Regulation of translation via stop codon readthrough (SC-RT) expands not only tissue-specific but also viral proteomes in humans and, therefore, represents an important subject of study. Understanding this mechanism and all involved players is critical also from a point of view of prospective medical therapies of hereditary diseases caused by a premature termination codon. tRNAs were considered for a long time to be just passive players delivering amino acid residues according to the genetic code to ribosomes without any active regulatory roles. In contrast, our recent yeast work identified several endogenous tRNAs implicated in the regulation of SC-RT. Swiftly emerging studies of human tRNA-ome also advocate that tRNAs have unprecedented regulatory potential. Here, we developed a universal U6 promotor-based system expressing various human endogenous tRNA iso-decoders to study consequences of their increased dosage on SC-RT employing various reporter systems in vivo. This system combined with siRNA-mediated downregulations of selected aminoacyl-tRNA synthetases demonstrated that changing levels of human tryptophan and tyrosine tRNAs do modulate efficiency of SC-RT. Overall, our results suggest that tissue-to-tissue specific levels of selected near-cognate tRNAs may have a vital potential to fine-tune the final landscape of the human proteome, as well as that of its viral pathogens.


Assuntos
Códon de Terminação , Biossíntese de Proteínas , RNA de Transferência de Triptofano/metabolismo , RNA de Transferência de Tirosina/metabolismo , Linhagem Celular , Genes Reporter , Humanos , Mutação , Plasmídeos/genética , Regiões Promotoras Genéticas , Proteínas/genética , RNA Nuclear Pequeno/genética , RNA de Transferência de Triptofano/genética , RNA de Transferência de Tirosina/genética , Triptofano-tRNA Ligase/genética , Proteína Supressora de Tumor p53/biossíntese , Proteína Supressora de Tumor p53/genética , Tirosina-tRNA Ligase/genética , Proteínas Virais/genética
7.
FEMS Microbiol Lett ; 367(18)2020 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-32926111

RESUMO

Streptococcus anginosus is frequently detected in patients with infective endocarditis, abscesses or oral cancer. Although S. anginosus is considered the causative pathogen of these diseases, the pathogenic mechanisms of the bacterium have remained unclear. Previously, we suggested that an extracellular antigen from S. anginosus (SAA) serves as a pathogenic factor by inducing nitric oxide production in murine macrophages. In the present study, we identified SAA using LC-MS/MS and assessed the biological activities of His-tagged recombinant SAA in murine macrophages. SAA was identified as a tyrosine tRNA synthetase (SaTyrRS) that was isolated from the extracellular fraction of S. anginosus but not from other oral streptococci. In addition, inducible nitric oxide synthase and TNF-α mRNA expression was induced in recombinant SaTyrRS-stimulated murine macrophages. However, their mRNA expression was not induced in macrophages stimulated with truncated or heat-inactivated recombinant SaTyrRS, and the activation motif was identified as Arg264-Thr270. Consequently, these results indicated that SaTyrRS could be a novel and specific immunomodulatory protein in S. anginosus.


Assuntos
Antígenos de Bactérias/imunologia , Streptococcus anginosus/patogenicidade , Tirosina-tRNA Ligase/imunologia , Fatores de Virulência/imunologia , Sequência de Aminoácidos , Animais , Antígenos de Bactérias/química , Antígenos de Bactérias/genética , Antígenos de Bactérias/metabolismo , Linhagem Celular , Espaço Extracelular/metabolismo , Humanos , Inflamação , Macrófagos/imunologia , Macrófagos/microbiologia , Camundongos , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/imunologia , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/metabolismo , Infecções Estreptocócicas/microbiologia , Streptococcus anginosus/enzimologia , Streptococcus anginosus/isolamento & purificação , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologia , Tirosina-tRNA Ligase/química , Tirosina-tRNA Ligase/genética , Tirosina-tRNA Ligase/metabolismo , Fatores de Virulência/química , Fatores de Virulência/genética , Fatores de Virulência/metabolismo
8.
J Cancer Res Clin Oncol ; 146(2): 329-342, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31912229

RESUMO

PURPOSE: Members of the aaRS (aminoacyl-tRNA synthetase) family are proteins controlling the aminoacylation process, in which YARS (tyrosyl-tRNA synthetase) catalyzes the binding of tyrosine to its cognate tRNA and plays an important role in basic biosynthesis. Several studies have demonstrated the association between YARS mutation and certain developmental abnormalities/diseases, yet YARS's linkage with cancer remains uncategorized. In this study, by combining in silico, in vitro, and in vivo studies, we explored the expressions and functions of YARS in gastric cancer (GC). METHODS: We evaluated YARS's distribution in tumor and paired normal tissues/specimens of GC by referring to large cohort online datasets and patient-derived tissue specimens. YARS-related changes were assessed by phenotypical/molecular experiments and RNA-sequencing analysis in GC cell lines harboring YARS knockdown or overexpression. RESULTS: Both the transcript and protein levels of YARS were evidently higher in gastric cancer tissues than in paired normal tissues. YARS knockdown induced repressed proliferation and invasiveness, as well as enhanced apoptosis in GC cell lines, while abnormally upregulating YARS expression promoted gastric cancer growth in vivo. We inferred based on RNA-sequencing that YARS modulates multiple cancerous signaling pathways and proved through cellular experiments that YARS promoted GC progression, as well as homologous recombination by activating PI3K-Akt signaling. CONCLUSIONS: By revealing the existence of a YARS-PI3K-Akt signaling axis in gastric cancer, we discovered that tRNA synthetase YARS is a novel tumorigenic factor, characterized by its upregulation in tumor-derived specimens, as well as its functions in promoting gastric cancer progression.


Assuntos
Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Neoplasias Gástricas/enzimologia , Tirosina-tRNA Ligase/metabolismo , Animais , Linhagem Celular Tumoral , Progressão da Doença , Feminino , Xenoenxertos , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Prognóstico , Transdução de Sinais , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Tirosina-tRNA Ligase/biossíntese , Tirosina-tRNA Ligase/genética , Regulação para Cima
9.
Biochem Pharmacol ; 169: 113634, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31513785

RESUMO

BACGROUND AND PURPOSE: Tumor chemotherapy and radiotherapy induces hematopoietic cell damage, resulting in thrombocytopenia. Conventional platelet transfusion strategies or drug therapies are used to treat thrombocytopenia. However, these therapies may result in a several side effects, including heightened susceptibility to infectious diseases and the formation of anti-TPO-antibodies. Therefore, a more secure strategy should be explored to overcome and compensate for the shortcomings of conventional strategies. EXPERIMENTAL APPROACH: Effects of rhTyrRS(Y341A) on the expression of VCAM-1 on the surface of HUVECs were determined by analysing mRNA expression, promoter activity, protein expression. The molecular mechanisms of the effects of rhTyrRS(Y341A) on the expression of VCAM-1 on the surface of HUVECs were investigated by determining the activation of VEGF-R II/NF-κB pathway. KEY RESULTS: Our results provide evidence that rhTyrRS (Y341A) activates NF-κB to upregulate VCAM-1 in a VEGF-R II/NF-κB pathway-dependent, resulting in megakaryocyte adhering to PVECs to induce platelet production. CONCLUSIONS: This study suggested that rhTyrRS (Y341A), a novel human tyrosyl-tRNA synthetase mutation, increased the platelet count under normal conditions. Further more, we confirmed that an NF-κB-mediated mechanism is involved in rhTyrRS (Y341A)-induced thrombopoiesis, which involves its interaction with VEGF-R II.


Assuntos
NF-kappa B/fisiologia , Trombopoese , Tirosina-tRNA Ligase/fisiologia , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/fisiologia , Animais , Células Cultivadas , Feminino , Humanos , Masculino , Mutação , Fosforilação , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/fisiologia , Tirosina-tRNA Ligase/genética , Molécula 1 de Adesão de Célula Vascular/análise , Molécula 1 de Adesão de Célula Vascular/genética
10.
FASEB J ; 33(7): 8083-8093, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30939244

RESUMO

Resveratrol (RSV) has broad prospective applications as a radiation protection drug, but its mechanism of action is not yet clear. Here, we found that 5 µM RSV can effectively reduce the cell death caused by irradiation. Irradiation leads to G2/M phase arrest in the cell cycle, whereas RSV treatment increases S-phase cell cycle arrest, which is associated with sirtuin 1 (SIRT1) regulation. Meanwhile, RSV promotes DNA damage repair, mainly by accelerating the efficiency of homologous recombination repair. Under oxidative stress, tyrosyl-tRNA synthetase (TyrRS) is transported to the nucleus to protect against DNA damage. RSV can promote TyrRS acetylation, thus promoting TyrRS to enter the nucleus, where it regulates the relevant signaling proteins and reduces apoptosis and DNA damage. SIRT1 is a deacetylase, and SIRT1 knockdown or inhibition can increase TyrRS acetylation levels, further reducing radiation-induced apoptosis after RSV treatment. Our study revealed a new radiation protection mechanism for RSV, in which the acetylation of TyrRS and its translocation into the nucleus is promoted, and this mechanism may also represent a novel protective target against irradiation.-Gao, P., Li, N., Ji, K., Wang, Y., Xu, C., Liu, Y., Wang, Q., Wang, J., He, N., Sun, Z., Du, L., Liu, Q. Resveratrol targets TyrRS acetylation to protect against radiation-induced damage.


Assuntos
Apoptose , Pontos de Checagem da Fase G2 do Ciclo Celular , Lesões Experimentais por Radiação , Resveratrol/farmacologia , Transdução de Sinais , Tirosina-tRNA Ligase , Animais , Apoptose/efeitos dos fármacos , Apoptose/genética , Apoptose/efeitos da radiação , Dano ao DNA , Reparo do DNA/efeitos dos fármacos , Reparo do DNA/genética , Reparo do DNA/efeitos da radiação , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem da Fase G2 do Ciclo Celular/genética , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos da radiação , Células HEK293 , Humanos , Pontos de Checagem da Fase M do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem da Fase M do Ciclo Celular/genética , Pontos de Checagem da Fase M do Ciclo Celular/efeitos da radiação , Lesões Experimentais por Radiação/genética , Lesões Experimentais por Radiação/metabolismo , Lesões Experimentais por Radiação/patologia , Lesões Experimentais por Radiação/prevenção & controle , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Transdução de Sinais/efeitos da radiação , Sirtuína 1/genética , Sirtuína 1/metabolismo , Tirosina-tRNA Ligase/genética , Tirosina-tRNA Ligase/metabolismo
11.
J Am Chem Soc ; 140(23): 7046-7051, 2018 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-29775058

RESUMO

Bioorthogonal tools enable cell-type-specific proteomics, a prerequisite to understanding biological processes in multicellular organisms. Here we report two engineered aminoacyl-tRNA synthetases for mammalian bioorthogonal labeling: a tyrosyl ( ScTyrY43G) and a phenylalanyl ( MmPheT413G) tRNA synthetase that incorporate azide-bearing noncanonical amino acids specifically into the nascent proteomes of host cells. Azide-labeled proteins are chemoselectively tagged via azide-alkyne cycloadditions with fluorophores for imaging or affinity resins for mass spectrometric characterization. Both mutant synthetases label human, hamster, and mouse cell line proteins and selectively activate their azido-bearing amino acids over 10-fold above the canonical. ScTyrY43G and MmPheT413G label overlapping but distinct proteomes in human cell lines, with broader proteome coverage upon their coexpression. In mice, ScTyrY43G and MmPheT413G label the melanoma tumor proteome and plasma secretome. This work furnishes new tools for mammalian residue-specific bioorthogonal chemistry, and enables more robust and comprehensive cell-type-specific proteomics in live mammals.


Assuntos
Metionina tRNA Ligase/genética , Proteoma/genética , Proteômica/métodos , Tirosina-tRNA Ligase/genética , Alcinos/química , Aminoácidos/química , Aminoácidos/genética , Animais , Azidas/química , Sequência de Bases , Células CHO , Química Click , Cricetulus , Reação de Cicloadição , Feminino , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Mutação , Engenharia de Proteínas/métodos , Saccharomyces cerevisiae/enzimologia
12.
Peptides ; 101: 60-68, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29289698

RESUMO

Kyotorphin (KTP; L-tyrosyl-l-arginine), an opioid-like analgesic discovered in the bovine brain, is potentially a neuromodulator because of its localization in synaptosomes, the existence of a specific KTP receptor, and the presence of its biosynthetic enzyme in the brain. KTP is formed in the brain from its constituent amino acids, L-tyrosine and L-arginine, by an enzyme termed KTP synthetase. However, the latter has never been identified. We aimed to test the hypothesis that tyrosyl-tRNA synthetase (TyrRS) is also KTP synthetase. We found that recombinant hTyrRS synthesizes KTP from tyrosine, arginine, and ATP, with Km = 1400 µM and 200 µM for arginine and tyrosine, respectively. TyrRS knockdown of PC12 cells with a small interfering RNA (siRNA) in the presence of 1.6 mM tyrosine, arginine, proline, or tryptophan significantly reduced the level of KTP, but not those of tyrosine-tyrosine, tyrosine-proline, or tyrosine-tryptophan. siRNA treatment did not affect cell survival or proliferation. In mice, TyrRS levels were found to be greater in the midbrain and medulla oblongata than in other brain regions. When arginine was administered 2 h prior to brain dissection, the KTP levels in these regions plus olfactory bulb significantly increased, although basal brain KTP levels remained relatively even. Our conclusion is further supported by a positive correlation across brain regions between TyrRS expression and arginine-accelerated KTP production.


Assuntos
Endorfinas/biossíntese , Regulação Enzimológica da Expressão Gênica/fisiologia , Bulbo/enzimologia , Mesencéfalo/enzimologia , Peptídeo Sintases/biossíntese , Tirosina-tRNA Ligase/biossíntese , Animais , Endorfinas/genética , Técnicas de Silenciamento de Genes , Humanos , Masculino , Bulbo/citologia , Mesencéfalo/citologia , Camundongos , Células PC12 , Peptídeo Sintases/genética , Ratos , Tirosina-tRNA Ligase/genética
13.
Sci Rep ; 7(1): 12184, 2017 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-28939876

RESUMO

Tumor radiotherapy induces hematopoietic organ damage and reduces thrombocyte counts. Thrombocytopenia is a common disease. Some studies have shown that tRNA synthetase plays not only catalytic tRNA aminoacylation roles, but also functions similarly to cytokines. Recombinant human tyrosyl-tRNA synthetase with a mutated Y341A (rhTyrRS (Y341A)) promotes megakaryocyte migrate from bone marrow to peripheral blood. It would promote megakaryocytes in the lungs adhering to vascular endothelial cells and resulting in the platelet production. The purpose of this research was to investigate the efficacy of rhTyrRS (Y341A) as a therapy for thrombocytopenia and to explore its mechanism of action. We found platelet number was effectively increased by rhTyrRS (Y341A) via platelet count and reticulated platelets (RPs) flow cytometry. We also demonstrated radiation-induced thrombocytopenia could be prevented by rhTyrRS (Y341A). The results of immunohistochemistry and H&E staining showed the number of pulmonary mature megakaryocytes was significantly increased in rhTyrRS (Y341A) treated groups. In transgenic zebrafish larvae, confocal microscopy results showed rhTyrRS (Y341A) promoted the migration and adhesion of megakaryocytes. These results suggested that rhTyrRS (Y341A) promote megakaryocytes in bone marrow migrating to lungs through blood circulation. rhTyrRS (Y341A) may be an effective medicine which could be used to treat patients suffering from thrombocytopenia.


Assuntos
Plaquetas/efeitos dos fármacos , Trombocitopenia/tratamento farmacológico , Trombopoese/efeitos dos fármacos , Tirosina-tRNA Ligase/administração & dosagem , Animais , Animais Geneticamente Modificados , Plaquetas/efeitos da radiação , Movimento Celular/efeitos dos fármacos , Modelos Animais de Doenças , Feminino , Células Endoteliais da Veia Umbilical Humana , Humanos , Masculino , Megacariócitos/efeitos dos fármacos , Megacariócitos/efeitos da radiação , Camundongos , Camundongos Endogâmicos C57BL , Mutação , Neoplasias/radioterapia , Contagem de Plaquetas , Radioterapia/efeitos adversos , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/genética , Trombocitopenia/etiologia , Trombopoese/efeitos da radiação , Resultado do Tratamento , Tirosina-tRNA Ligase/genética , Peixe-Zebra
15.
Methods ; 113: 3-12, 2017 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-27780756

RESUMO

Aminoacyl-tRNA synthetases play a central role in protein synthesis, catalyzing the attachment of amino acids to their cognate tRNAs. Here, we describe a spectrophotometric assay for tyrosyl-tRNA synthetase in which the Tyr-tRNA product is cleaved, regenerating the tRNA substrate. As tRNA is the limiting substrate in the assay, recycling it substantially increases the sensitivity of the assay while simultaneously reducing its cost. The tRNA aminoacylation reaction is monitored spectrophotometrically by coupling the production of AMP to the conversion of NAD+ to NADH. We have adapted the tyrosyl-tRNA synthetase assay to monitor: (1) aminoacylation of tRNA by l- or d-tyrosine, (2) cyclodipeptide formation by cyclodipeptide synthases, (3) hydrolysis of d-aminoacyl-tRNAs by d-tyrosyl-tRNA deacylase, and (4) post-transfer editing by aminoacyl-tRNA synthetases. All of these assays are continuous and homogenous, making them amenable for use in high-throughput screens of chemical libraries. In the case of the cyclodipeptide synthase, d-tyrosyl-tRNA deacylase, and post-transfer editing assays, the aminoacyl-tRNAs are generated in situ, avoiding the need to synthesize and purify aminoacyl-tRNA substrates prior to performing the assays. Lastly, we describe how the tyrosyl-tRNA synthetase assay can be adapted to monitor the activity of other aminoacyl-tRNA synthetases and how the approach to regenerating the tRNA substrate can be used to increase the sensitivity and decrease the cost of commercially available aminoacyl-tRNA synthetase assays.


Assuntos
Monofosfato de Adenosina/biossíntese , Ensaios Enzimáticos , RNA de Transferência de Tirosina/genética , Aminoacilação de RNA de Transferência , Tirosina-tRNA Ligase/metabolismo , Tirosina/metabolismo , Aminoaciltransferases/genética , Aminoaciltransferases/metabolismo , Escherichia coli/enzimologia , Escherichia coli/genética , Expressão Gênica , Geobacillus stearothermophilus/enzimologia , Geobacillus stearothermophilus/genética , Hidrólise , Cinética , Mycobacterium tuberculosis/enzimologia , Mycobacterium tuberculosis/genética , NAD/metabolismo , Peptídeos Cíclicos/biossíntese , RNA de Transferência de Tirosina/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Sensibilidade e Especificidade , Espectrofotometria , Estereoisomerismo , Tirosina-tRNA Ligase/genética
16.
J Mol Graph Model ; 71: 192-199, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27939931

RESUMO

The stereospecificity of aminoacyl-tRNA synthetases helps exclude d-amino acids from protein synthesis and could perhaps be engineered to allow controlled d-amino acylation of tRNA. We use molecular dynamics simulations to probe the stereospecificity of the class I tyrosyl- and glutaminyl-tRNA synthetases (TyrRS, GlnRS), including wildtype enzymes and three point mutants suggested by three different protein design methods. l/d binding free energy differences are obtained by alchemically and reversibly transforming the ligand from L to D in simulations of the protein-ligand complex. The D81Q mutation in Escherichia coli TyrRS is homologous to the D81R mutant shown earlier to have inverted stereospecificity. D81Q is predicted to lead to a rotated ligand backbone and an increased, not a decreased l-Tyr preference. The E36Q mutation in Methanococcus jannaschii TyrRS has a predicted l/d binding free energy difference ΔΔG of just 0.5±0.9kcal/mol, compared to 3.1±0.8kcal/mol for the wildtype enzyme (favoring l-Tyr). The ligand ammonium position is preserved in the d-Tyr complex, while the carboxylate is shifted. Wildtype GlnRS has a similar preference for l-glutaminyl adenylate; the R260Q mutant has an increased preference, even though Arg260 makes a large contribution to the wildtype ΔΔG value.


Assuntos
Aminoacil-tRNA Sintetases/química , Simulação de Dinâmica Molecular , Biossíntese de Proteínas/genética , Tirosina-tRNA Ligase/química , Monofosfato de Adenosina/química , Aminoácidos/química , Aminoácidos/genética , Aminoacil-tRNA Sintetases/genética , Escherichia coli/enzimologia , Methanocaldococcus/enzimologia , Mutação Puntual , Engenharia de Proteínas , Tirosina-tRNA Ligase/genética
17.
Am J Med Genet A ; 173(1): 126-134, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27633801

RESUMO

Aminoacyl-tRNA synthetases (ARSs) are a group of ubiquitously expressed enzymes that are best known for their function in the first step of protein translation but have been increasingly associated with secondary functions including transcription and translation control and extracellular signaling. Mutations in numerous ARSs have been linked to a growing number of both autosomal dominant and autosomal recessive human diseases. The tyrosyl-tRNA synthetase (YARS) links the amino acid tyrosine to its cognate tRNA. We report two siblings who presented with failure to thrive (FTT), hypertriglyceridemia, developmental delay, liver dysfunction, lung cysts, and abnormal subcortical white matter. Using exome sequencing the siblings were found to harbor bi-allelic pathogenic-appearing variants within the YARS gene (NM_003680.3):c.638C>T p.(Pro213Leu) and c.1573G>A p.(Gly525Arg). These YARS variants occur in the catalytic domain and the C-terminal domain, respectively. Mutations in YARS have been previously associated with an autosomal dominant form of Charcot-Marie-Tooth (CMT); our findings suggest the disease spectrum associated with YARS dysregulation is broader than peripheral neuropathy. © 2016 Wiley Periodicals, Inc.


Assuntos
Genes Dominantes , Estudos de Associação Genética , Doenças Genéticas Inatas/diagnóstico , Doenças Genéticas Inatas/genética , Mutação , Fenótipo , Tirosina-tRNA Ligase/genética , Alelos , Fácies , Genótipo , Humanos , Lactente , Imageamento por Ressonância Magnética , Masculino , Modelos Moleculares , Linhagem , Conformação Proteica , Análise de Sequência de DNA , Irmãos , Tomografia Computadorizada por Raios X , Tirosina-tRNA Ligase/química
19.
Nucleic Acids Res ; 44(3): 1247-55, 2016 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-26773056

RESUMO

Many human tRNA synthetases evolved alternative functions outside of protein synthesis. These functions are associated with over 200 splice variants (SVs), most of which are catalytic nulls that engender new biology. While known to regulate non-translational activities, little is known about structures resulting from natural internal ablations of any protein. Here, we report analysis of two closely related, internally deleted, SVs of homodimeric human tyrosyl-tRNA synthetase (TyrRS). In spite of both variants ablating a portion of the catalytic core and dimer-interface contacts of native TyrRS, each folded into a distinct stable structure. Biochemical and nuclear magnetic resonance (NMR) analysis showed that the internal deletion of TyrRSΔE2-4 SV gave an alternative, neomorphic dimer interface 'orthogonal' to that of native TyrRS. In contrast, the internal C-terminal splice site of TyrRSΔE2-3 prevented either dimerization interface from forming, and yielded a predominantly monomeric protein. Unlike ubiquitous TyrRS, the neomorphs showed clear tissue preferences, which were distinct from each other. The results demonstrate a sophisticated structural plasticity of a human tRNA synthetase for architectural reorganizations that are preferentially elicited in specific tissues.


Assuntos
Processamento Alternativo , Multimerização Proteica , Estrutura Secundária de Proteína , Tirosina-tRNA Ligase/química , Tirosina-tRNA Ligase/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Western Blotting , Domínio Catalítico/genética , Linhagem Celular , Linhagem Celular Tumoral , Perfilação da Expressão Gênica , Humanos , Isoenzimas/química , Isoenzimas/genética , Isoenzimas/metabolismo , Células Jurkat , Espectroscopia de Ressonância Magnética , Camundongos , Modelos Moleculares , Dados de Sequência Molecular , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Deleção de Sequência , Homologia de Sequência de Aminoácidos , Tirosina-tRNA Ligase/metabolismo
20.
Cardiovasc Ther ; 34(1): 4-12, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26400816

RESUMO

AIMS: The purpose of this study was to clarify the effect of mini-tyrosyl-tRNA synthetase/mini-tryptophanyl-tRNA synthetase (mini-TyrRS/mini-TrpRS) in ischemic angiogenesis in rhesus monkeys with acute myocardial infarction (AMI). METHODS: A 27-gauge needle was incorporated percutaneously into the left ventricular myocardium of rhesus monkeys with AMI. All monkeys were randomized to receive adenoviral vector mini-TyrRS/mini-TrpRS, which was administered as five injections into the infarcted myocardium, or saline or ad-null (control groups). The injections were guided by EnSite NavX left ventricular electroanatomical mapping. Mini-TyrRS/mini-TrpRS proteins were detected by Western blot and immunoprecipitation analyses. Microvessel density (MVD) per section was measured using immunostaining with a CD34 monoclonal antibody. Proliferating cardiomyocytes were identified through histological and immunohistochemical analyses. Myocardial perfusion and cardiac function were estimated by G-SPECT. Infarction size was also measured. RESULTS: Western blot analyses showed that compared to the normal zone, the expression level of mini-TyrRS/mini-TrpRS was significantly different in the infarction zone. G-SPECT analysis indicated that the mini-TyrRS group had better cardiac function and myocardial perfusion after the injection of ad-mini-TyrRS than before, while mini-TrpRS injection had a totally opposite effect. After mini-TyrRS was administered, there was less of an infarction zone and more proliferating cardiomyocytes and capillaries in the mini-TyrRS group compared to both of the control groups, and the ad-mini-TrpRS group had a totally opposite effect. CONCLUSION: These results indicated that angiogenesis could be either stimulated by mini-TyrRS or inhibited by mini-TrpRS.


Assuntos
Capilares/enzimologia , Terapia Genética/métodos , Infarto do Miocárdio/terapia , Neovascularização Fisiológica , Fragmentos de Peptídeos/biossíntese , Triptofano-tRNA Ligase/biossíntese , Tirosina-tRNA Ligase/biossíntese , Adenoviridae/genética , Animais , Antígenos CD34/metabolismo , Capilares/fisiopatologia , Proliferação de Células , Circulação Coronária , Modelos Animais de Doenças , Técnicas de Transferência de Genes , Vetores Genéticos , Macaca mulatta , Masculino , Infarto do Miocárdio/enzimologia , Infarto do Miocárdio/genética , Infarto do Miocárdio/patologia , Infarto do Miocárdio/fisiopatologia , Miócitos Cardíacos/enzimologia , Miócitos Cardíacos/patologia , Fragmentos de Peptídeos/genética , Recuperação de Função Fisiológica , Triptofano-tRNA Ligase/genética , Tirosina-tRNA Ligase/genética , Função Ventricular Esquerda
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