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1.
Emerg Microbes Infect ; 9(1): 517-519, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32116136

RESUMO

We report a recent (2018) gonorrhoeal urethritis caused by a multidrug-resistant Neisseria gonorrhoeae strain in China. The isolated N. gonorrhoeae strain from a male and female pair expressed high-level resistance to spectinomycin (SPC), azithromycin, and other antibiotics but was sensitive to ceftriaxone. The SPC high-level resistance (MIC = 2048 mg/L) was due to a small deletion in rspE that caused two amino acid changes in ribosomal protein S5.


Assuntos
Farmacorresistência Bacteriana Múltipla , Neisseria gonorrhoeae/efeitos dos fármacos , Espectinomicina/farmacologia , China , Neisseria gonorrhoeae/genética , Neisseria gonorrhoeae/metabolismo , Fenótipo , Proteínas Ribossômicas/genética , Proteínas Ribossômicas/metabolismo
2.
Nat Commun ; 10(1): 5611, 2019 12 09.
Artigo em Inglês | MEDLINE | ID: mdl-31819057

RESUMO

Oxidation and alkylation of nucleobases are known to disrupt their base-pairing properties within RNA. It is, however, unclear whether organisms have evolved general mechanism(s) to deal with this damage. Here we show that the mRNA-surveillance pathway of no-go decay and the associated ribosome-quality control are activated in response to nucleobase alkylation and oxidation. Our findings reveal that these processes are important for clearing chemically modified mRNA and the resulting aberrant-protein products. In the absence of Xrn1, the level of damaged mRNA significantly increases. Furthermore, deletion of LTN1 results in the accumulation of protein aggregates in the presence of oxidizing and alkylating agents. This accumulation is accompanied by Hel2-dependent regulatory ubiquitylation of ribosomal proteins. Collectively, our data highlight the burden of chemically damaged mRNA on cellular homeostasis and suggest that organisms evolved mechanisms to counter their accumulation.


Assuntos
Estresse Oxidativo , Ribossomos/metabolismo , 4-Nitroquinolina-1-Óxido/metabolismo , Alquilação , Adutos de DNA/metabolismo , Dano ao DNA , Células HEK293 , Humanos , Metanossulfonato de Metila/farmacologia , Mutação/genética , Oxirredução , Peptídeos/metabolismo , Polirribossomos/metabolismo , Agregados Proteicos , Quinolonas/metabolismo , Estabilidade de RNA , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas Ribossômicas/metabolismo , Ribossomos/efeitos dos fármacos , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Ubiquitina/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação
3.
PLoS Genet ; 15(12): e1008513, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31841522

RESUMO

Whereas complete loss of Rp function is generally lethal, most heterozygous Rp mutants grow more slowly and are subject to competitive loss from mosaics tissues that also contain wild type cells. The rpS12 gene has a special role in the cell competition of other Ribosomal Protein (Rp) mutant cells in Drosophila. Elimination by cell competition is promoted by higher RpS12 levels and prevented by a specific rpS12 mis-sense mutation, identifying RpS12 as a key effector of cell competition due to mutations in other Rp genes. Here we show that RpS12 is also required for other aspects of Rp mutant phenotypes, including hundreds of gene expression changes that occur in 'Minute' Rp heterozygous wing imaginal discs, overall translation rate, and the overall rate of organismal development, all through the bZip protein Xrp1 that is one of the RpS12-regulated genes. Our findings outline the regulatory response to mutations affecting essential Rp genes that controls overall translation, growth, and cell competition, and which may contribute to cancer and other diseases.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/crescimento & desenvolvimento , Discos Imaginais/crescimento & desenvolvimento , Biossíntese de Proteínas , Proteínas Ribossômicas/genética , Animais , Proteínas de Drosophila/genética , Drosophila melanogaster/metabolismo , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Discos Imaginais/metabolismo , Masculino , Mutação de Sentido Incorreto , Proteínas Ribossômicas/metabolismo , Análise de Sequência de RNA
4.
Nat Commun ; 10(1): 5026, 2019 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-31690716

RESUMO

The majority of patients with neuroblastoma due to MYCN oncogene amplification and consequent N-Myc oncoprotein over-expression die of the disease. Here our analyses of RNA sequencing data identify the long noncoding RNA lncNB1 as one of the transcripts most over-expressed in MYCN-amplified, compared with MYCN-non-amplified, human neuroblastoma cells and also the most over-expressed in neuroblastoma compared with all other cancers. lncNB1 binds to the ribosomal protein RPL35 to enhance E2F1 protein synthesis, leading to DEPDC1B gene transcription. The GTPase-activating protein DEPDC1B induces ERK protein phosphorylation and N-Myc protein stabilization. Importantly, lncNB1 knockdown abolishes neuroblastoma cell clonogenic capacity in vitro and leads to neuroblastoma tumor regression in mice, while high levels of lncNB1 and RPL35 in human neuroblastoma tissues predict poor patient prognosis. This study therefore identifies lncNB1 and its binding protein RPL35 as key factors for promoting E2F1 protein synthesis, N-Myc protein stability and N-Myc-driven oncogenesis, and as therapeutic targets.


Assuntos
Carcinogênese/genética , RNA Longo não Codificante/metabolismo , Proteínas Ribossômicas/metabolismo , Animais , Carcinogênese/patologia , Linhagem Celular Tumoral , Proliferação de Células/genética , Sobrevivência Celular/genética , Fator de Transcrição E2F1/metabolismo , Feminino , Proteínas Ativadoras de GTPase/genética , Proteínas Ativadoras de GTPase/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos Endogâmicos BALB C , Camundongos Nus , Proteína Proto-Oncogênica N-Myc/metabolismo , Neuroblastoma/genética , Neuroblastoma/patologia , Prognóstico , Biossíntese de Proteínas , Estabilidade Proteica , RNA Longo não Codificante/genética , Transcrição Genética , Regulação para Cima/genética
5.
Expert Opin Ther Pat ; 29(12): 987-1009, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31722579

RESUMO

Introduction: The ubiquitously expressed 37 kDa/67 kDa high-affinity laminin receptor (laminin receptor precursor/laminin receptor, LRP/LR) is a protein found to play several roles within cells. The receptor is located in the nucleus, cytosol and the cell surface. LRP/LR mediates cell proliferation, cell adhesion and cell differentiation. As a result, it is seen to enhance tumor angiogenesis as well as invasion and adhesion, key steps in the metastatic cascade of cancer. Recent findings have shown that LRP/LR is involved in the maintenance of cell viability through apoptotic evasion, allowing for tumor progression. Thus, several patented therapeutic approaches targeting the receptor for the prevention and treatment of cancer have emerged.Areas covered: The several roles that LRP/LR plays in cancer progression as well as an overview of the current therapeutic patented strategies targeting LRP/LR and cancer to date.Expert opinion: Small molecule inhibitors, monoclonal antibodies and small interfering RNAs might act used as powerful tools in preventing tumor angiogenesis and metastasis through the induction of apoptosis and telomere erosion in several cancers. This review offers an overview of the roles played by LRP/LR in cancer progression, while providing novel patented approaches targeting the receptor as potential therapeutic routes for the treatment of cancer as well as various other diseases.


Assuntos
Antineoplásicos/farmacologia , Neoplasias/tratamento farmacológico , Receptores de Laminina/antagonistas & inibidores , Proteínas Ribossômicas/antagonistas & inibidores , Animais , Progressão da Doença , Desenho de Drogas , Humanos , Terapia de Alvo Molecular , Neoplasias/patologia , Neovascularização Patológica/tratamento farmacológico , Neovascularização Patológica/patologia , Patentes como Assunto , Receptores de Laminina/metabolismo , Proteínas Ribossômicas/metabolismo
6.
Dis Markers ; 2019: 3863458, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31565098

RESUMO

Objective: Circular RNAs (circRNAs) have been reported to be widely involved in pathological processes of various cancers. However, little is known about their diagnostic values in early gastric cancer (EGC). This study is aimed at exploring whether circulating circRNAs in plasma could act as biomarkers for EGC diagnosis. Materials and Methods: Mass spectrometry (MS) was performed to identify the proteins that at significantly aberrantly levels in gastric cancer (GC) tissues. The target circRNA was identified by bioinformatics analysis. A receiver operating characteristic (ROC) curve was generated to evaluate the diagnostic utility. Results: MS revealed that the ribosomal protein L6 (RPL6) expression was significantly downregulated only in EGC tissues vs. nontumorous tissues; this was validated by western blotting (n = 30, p = 0.0094). Bioinformatics analysis predicted that there is a hsa_circ_0006848/hsa_miR-329-5p/RPL6 axis in GC progression. The hsa_circ_0006848 expression was significantly downregulated in EGC tissues (vs. nontumorous tissues, n = 30, p = 0.0073) and plasma samples from EGC patients (vs. paired healthy volunteers, n = 30, p = 0.0089). In addition, the hsa_circ_0006848 plasma level in postoperative patients was significantly higher than that of preoperative patients (n = 30, p = 0.047). Furthermore, the decreased hsa_circ_0006848 expression in plasma was negatively correlated with poor differentiation (p = 0.037) and tumor size (p = 0.046). The area under the ROC curve (AUC) of hsa_circ_0006848 in plasma was 0.733, suggesting a good diagnostic value. The plasma hsa_circ_0006848 level combined with the carcinoembryonic antigen (CEA), carbohydrate-associated antigen 19-9 (CA19-9), and carbohydrate-associated antigen 72-4 (CA72-4) level increased the AUC to 0.825. Conclusion: Our results indicated that plasma hsa_circ_0006848 may be a novel noninvasive biomarker in EGC diagnosis.


Assuntos
Biomarcadores Tumorais/sangue , Ácidos Nucleicos Livres/sangue , Proteínas Ribossômicas/genética , Neoplasias Gástricas/sangue , Biomarcadores Tumorais/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas Ribossômicas/metabolismo , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia
7.
Nat Struct Mol Biol ; 26(10): 919-929, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31570874

RESUMO

Cotranslational protein targeting is a conserved process for membrane protein biogenesis. In Escherichia coli, the essential ATPase SecA was found to cotranslationally target a subset of nascent membrane proteins to the SecYEG translocase at the plasma membrane. The molecular mechanism of this pathway remains unclear. Here we use biochemical and cryoelectron microscopy analyses to show that the amino-terminal amphipathic helix of SecA and the ribosomal protein uL23 form a composite binding site for the transmembrane domain (TMD) on the nascent protein. This binding mode further enables recognition of charged residues flanking the nascent TMD and thus explains the specificity of SecA recognition. Finally, we show that membrane-embedded SecYEG promotes handover of the translating ribosome from SecA to the translocase via a concerted mechanism. Our work provides a molecular description of the SecA-mediated cotranslational targeting pathway and demonstrates an unprecedented role of the ribosome in shielding nascent TMDs.


Assuntos
Escherichia coli K12/metabolismo , Proteínas de Escherichia coli/metabolismo , Proteínas Ribossômicas/metabolismo , /metabolismo , Sítios de Ligação , Microscopia Crioeletrônica , Escherichia coli K12/química , Proteínas de Escherichia coli/química , Modelos Moleculares , Biossíntese de Proteínas , Domínios Proteicos , Estrutura Secundária de Proteína , Proteínas Ribossômicas/química , Canais de Translocação SEC/química , Canais de Translocação SEC/metabolismo , /química
8.
Nat Commun ; 10(1): 4563, 2019 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-31594941

RESUMO

Ribosome-synthesized post-translationally modified peptides (RiPPs) represent a rapidly expanding class of natural products with various biological activities. Linear azol(in)e-containing peptides (LAPs) comprise a subclass of RiPPs that display outstanding diversity of mechanisms of action while sharing common structural features. Here, we report the discovery of a new LAP biosynthetic gene cluster in the genome of Rhizobium Pop5, which encodes the precursor peptide and modification machinery of phazolicin (PHZ) - an extensively modified peptide exhibiting narrow-spectrum antibacterial activity against some symbiotic bacteria of leguminous plants. The cryo-EM structure of the Escherichia coli 70S-PHZ complex reveals that the drug interacts with the 23S rRNA and uL4/uL22 proteins and obstructs ribosomal exit tunnel in a way that is distinct from other compounds. We show that the uL4 loop sequence determines the species-specificity of antibiotic action. PHZ expands the known diversity of LAPs and may be used in the future as biocontrol agent for agricultural needs.


Assuntos
Antibacterianos/farmacologia , Azóis/farmacologia , Agentes de Controle Biológico/farmacologia , Peptídeos/farmacologia , Biossíntese de Proteínas/efeitos dos fármacos , Ribossomos/efeitos dos fármacos , Antibacterianos/química , Antibacterianos/metabolismo , Azóis/química , Azóis/metabolismo , Agentes de Controle Biológico/química , Agentes de Controle Biológico/metabolismo , Microscopia Crioeletrônica , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Proteínas de Escherichia coli/ultraestrutura , Testes de Sensibilidade Microbiana , Família Multigênica , Biossíntese Peptídica/genética , Peptídeos/química , Peptídeos/metabolismo , Phaseolus/microbiologia , RNA Ribossômico 23S/metabolismo , RNA Ribossômico 23S/ultraestrutura , Rhizobium/genética , Rhizobium/metabolismo , Proteínas Ribossômicas/genética , Proteínas Ribossômicas/metabolismo , Proteínas Ribossômicas/ultraestrutura , Ribossomos/metabolismo , Ribossomos/ultraestrutura , Especificidade da Espécie , Simbiose
9.
Biochimie ; 167: 61-67, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31520657

RESUMO

Ribosomal protein S6 in Escherichia coli is modified by ATP-dependent glutamate ligase RimK. Up to four glutamate residues are added to the C-terminus of S6 protein. In this work we demonstrated that unlike the majority of ribosome modifications in E. coli, oligoglutamylation of S6 protein is regulated and happens only in the stationary phase of bacterial culture. Only S6 protein incorporated into assembled small ribosomal subunits, but not newly made free S6 protein is a substrate for RimK protein. Overexpression of the rimK gene leads to the modification of S6 protein even in the exponential phase of bacterial culture. Thus, it is unlikely that any stationary phase specific factor is needed for the modification. We propose a model that S6 modification is regulated solely via the rate of ribosome biosynthesis at limiting concentration of RimK enzyme.


Assuntos
Proteínas de Escherichia coli/metabolismo , Escherichia coli/metabolismo , Ácido Glutâmico/metabolismo , Peptídeo Sintases/metabolismo , Proteína S6 Ribossômica/metabolismo , Proteínas Ribossômicas/metabolismo , Escherichia coli/crescimento & desenvolvimento , Processamento de Proteína Pós-Traducional , Ribossomos/metabolismo
10.
Biochim Biophys Acta Mol Cell Biol Lipids ; 1864(12): 158528, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31520776

RESUMO

Ribosomal protein L8 (RPL8) was considered as a promising candidate gene for the milk fat percentage trait in dairy cattle in our previous genome-wide association studies, but the mechanism remains to be determined. Here we investigated the molecular mechanism underlying the effect of bovine RPL8 on milk fat percentage. We demonstrated that RPL8 silencing in bovine mammary epithelial cells affected the expression of genes encoding fat-related enzymes (ACACA, FASN, ACSS1, FABP3, SREBP-1, DGAT1, GPAM, PLIN2, PLIN5 and CIDEA). Furthermore, we showed here that a single nucleotide polymorphism, g.-931G > T (chr14:1508300, UMD3.1) in the putative RPL8 promoter region significantly reduced its promoter activity. Interestingly, this decrease in activity was paralleled by lower RPL8 expression in mammary gland tissues of dairy cattle with the homozygous TT genotype compared to that of cattle with the wild-type homozygous GG genotype. Importantly, we found g.-931G > T added a paired box 6 (Pax6)-binding site and this mutation located in the presumed Pax6-binding site. EMSA and co-immunoprecipitation (Co-IP) assays confirmed the interaction between RPL8 and Pax6 and the T allele exhibited a higher affinity of DNA/protein interactions than G allele, suggesting that Pax6 is an important transcription factor for RPL8 expression. In addition, lactating cows with the GG and GT genotypes presented a significant decrease in milk fat percentage compared to cows with TT genotypes. Altogether, our study indicated that g.-931G > T at RPL8 promoter altered its expression by affecting the interplay between Pax6 and RPL8, which may account for the association with milk fat traits. Findings herein first elucidated the biological function of RPL8 gene in milk fat and the identified SNP g.-931G > T may be considered as genetic makers for breeding in dairy cattle.


Assuntos
Bovinos/genética , Gorduras/metabolismo , Leite/metabolismo , Fator de Transcrição PAX6/metabolismo , Proteínas Ribossômicas/genética , Animais , Bovinos/metabolismo , Regulação para Baixo , Gorduras/química , Feminino , Lactação , Leite/química , Polimorfismo de Nucleotídeo Único , Regiões Promotoras Genéticas , Ligação Proteica , Proteínas Ribossômicas/metabolismo , Ativação Transcricional
11.
Biomed Pharmacother ; 118: 109386, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31545291

RESUMO

Long noncoding RNAs (lncRNAs) play vital roles in the development and progression of hepatocellular carcinoma (HCC). The recent study finds a strong correlation between lncRNA small nucleolar RNA host gene 7 (SNHG7) and HCC metastasis. However, the molecular mechanism by which SNHG7 regulates HCC progression has not been investigated. In this study, we found that SNHG7 was highly expressed in HCC tissues compared to non-tumor tissues. Data from public databases consistently indicated the up-regulated expression of SNHG7 in HCC. Furthermore, the levels of SNHG7 were up-regulated in four HCC cell lines (Huh7, Hep3B, HCCLM3, MHCC97 H) compared with LO2 cells. Interestingly, the elevated expression of SNHG7 was closely correlated with advanced tumor stages, high tumor grades, vascular invasion and poor prognosis of HCC. Knockdown of SNHG7 markedly inhibited cell proliferation, migration and invasion in HCCLM3 and MHCC97H cells, and prominently suppressed the growth and metastasis of HCCLM3 cells in vivo. Mechanistically, SNHG7 silencing increased the level of miR-122-5p in HCC cells. Luciferase reporter assay revealed the direct interaction between SNHG7 and miR-122-5p. Moreover, SNHG7 knockdown decreased the levels of ribosomal protein L4 (RPL4) mRNA and protein in HCC cells. Accordingly, the stability of RPL4 mRNA was reduced by SNHG7 silencing. More importantly, either miR-122-5p knockdown or RPL4 restoration partially reversed SNHG7 silencing-induced tumor suppressive effects on HCC cells. In conclusion, we demonstrated that SNHG7 expression was up-regulated in HCC. SNHG7 contributed to HCC progression by regulating miR-122-5p and RPL4. Therefore, SNHG7 might be a potential biomarker and therapeutic target for HCC.


Assuntos
Carcinoma Hepatocelular/genética , Movimento Celular/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Hepáticas/genética , MicroRNAs/metabolismo , RNA Longo não Codificante/metabolismo , Proteínas Ribossômicas/metabolismo , Animais , Sequência de Bases , Carcinogênese/genética , Carcinogênese/patologia , Carcinoma Hepatocelular/patologia , Proliferação de Células/genética , Técnicas de Silenciamento de Genes , Células Hep G2 , Humanos , Neoplasias Hepáticas/patologia , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , MicroRNAs/genética , Invasividade Neoplásica , Metástase Neoplásica , Prognóstico , RNA Longo não Codificante/genética , Regulação para Cima/genética
12.
Cancer Sci ; 110(11): 3510-3519, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31487418

RESUMO

NOP2/Sun domain family, member 2 (NSUN2) is a nuclear RNA methyl-transferase catalyzing 5-methylcytosine formation. Evidence shows that NSUN2 is correlated with cell unlimited proliferation. However, its functional role in gallbladder carcinoma (GBC), which is the most common biliary tract malignancy and has a poor prognosis, remains to be determined. Here we found that NSUN2 was highly expressed in GBC tissues as well as cell lines. NSUN2 silencing repressed GBC cell proliferation and tumorigenesis both in vitro and in vivo. Conversely, upregulation of NSUN2 enhanced GBC cell growth and colony formation. We further discovered that RPL6 was a closely interacting partner with NSUN2. Silencing RPL6 resulted in insufficient NSUN2 translational level and accumulative NSUN2 transcriptional level. Exogenous expression of NSUN2 partially rescued the effect of RPL6 in gallbladder cancer progression. Taken together, our data provided novel mechanic insights into the function of NSUN2 in GBC, thus pointing to NSUN2 as a potential and effective therapeutic approach to GBC treatment.


Assuntos
Carcinoma/metabolismo , Neoplasias da Vesícula Biliar/metabolismo , Metiltransferases/metabolismo , Proteínas de Neoplasias/metabolismo , Proteínas Ribossômicas/metabolismo , Animais , Carcinoma/patologia , Carcinoma/terapia , Linhagem Celular Tumoral , Proliferação de Células , Colecistite/metabolismo , Progressão da Doença , Neoplasias da Vesícula Biliar/patologia , Neoplasias da Vesícula Biliar/terapia , Humanos , Metiltransferases/antagonistas & inibidores , Camundongos , Camundongos Nus , Ensaio Tumoral de Célula-Tronco , Regulação para Cima
13.
PLoS Pathog ; 15(9): e1007951, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31479498

RESUMO

Necrosis and ethylene-inducing peptide 1 (Nep1)-like proteins (NLPs) are secreted by several phytopathogenic microorganisms. They trigger necrosis in various eudicot plants upon binding to plant sphingolipid glycosylinositol phosphorylceramides (GIPC). Interestingly, HaNLP3 from the obligate biotroph oomycete Hyaloperonospora arabidopsidis does not induce necrosis. We determined the crystal structure of HaNLP3 and showed that it adopts the NLP fold. However, the conformations of the loops surrounding the GIPC headgroup-binding cavity differ from those of cytotoxic Pythium aphanidermatum NLPPya. Essential dynamics extracted from µs-long molecular dynamics (MD) simulations reveals a limited conformational plasticity of the GIPC-binding cavity in HaNLP3 relative to toxic NLPs. This likely precludes HaNLP3 binding to GIPCs, which is the underlying reason for the lack of toxicity. This study reveals that mutations at key protein regions cause a switch between non-toxic and toxic phenotypes within the same protein scaffold. Altogether, these data provide evidence that protein flexibility is a distinguishing trait of toxic NLPs and highlight structural determinants for a potential functional diversification of non-toxic NLPs utilized by biotrophic plant pathogens.


Assuntos
Oomicetos/genética , Oomicetos/metabolismo , Doenças das Plantas/parasitologia , Sequência de Aminoácidos , Etilenos/metabolismo , Necrose/metabolismo , Peptídeos/metabolismo , Peronospora/genética , Proteínas/metabolismo , Proteínas Ribossômicas/genética , Proteínas Ribossômicas/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo
14.
Int J Med Sci ; 16(8): 1132-1141, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31523176

RESUMO

Ribosomal biogenesis is responsible for protein synthesis in all eukaryotic cells. Perturbation of ribosomal biogenesis processes can cause dysfunctions of protein synthesis and varieties of human diseases. In this study, we examine the role of RPL15, a large ribosomal subunit protein, in human colon carcinogenesis. Our results reveal that RPL15 is remarkably upregulated in human primary colon cancer tissues and cultured cell lines when compared with paired non-cancerous tissues and non-transformed epithelium cells. Elevated expression of RPL15 in colon cancer tissues is closely correlated with clinicopathological characteristics in patients. We determine the effects of RPL15 on nucleolar maintenance, ribosomal biogenesis and cell proliferation in human cells. We show that RPL15 is required for maintenance of nucleolar structure and formation of pre-60S subunits in the nucleoli. Depletion of RPL15 causes ribosomal stress, resulting in a G1-G1/S cell cycle arrest in non-transformed human epithelium cells, but apoptosis in colon cancer cells. Together, these results indicate that RPL15 is involved in human colon carcinogenesis and might be a potential clinical biomarker and/or target for colon cancer therapy.


Assuntos
Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Proteínas Ribossômicas/metabolismo , Idoso , Apoptose/genética , Pontos de Checagem do Ciclo Celular , Nucléolo Celular/metabolismo , Nucléolo Celular/ultraestrutura , Neoplasias do Colo/genética , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Feminino , Regulação Neoplásica da Expressão Gênica , Células HCT116 , Células HeLa , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas Ribossômicas/genética
15.
Nucleic Acids Res ; 47(16): 8649-8661, 2019 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-31392997

RESUMO

Viroids are naked RNAs that do not code for any known protein and yet are able to infect plants causing severe diseases. Because of their RNA nature, many studies have focused on the involvement of viroids in RNA-mediated gene silencing as being their pathogenesis mechanism. Here, the alterations caused by the Citrus exocortis viroid (CEVd) on the tomato translation machinery were studied as a new aspect of viroid pathogenesis. The presence of viroids in the ribosomal fractions of infected tomato plants was detected. More precisely, CEVd and its derived viroid small RNAs were found to co-sediment with tomato ribosomes in vivo, and to provoke changes in the global polysome profiles, particularly in the 40S ribosomal subunit accumulation. Additionally, the viroid caused alterations in ribosome biogenesis in the infected tomato plants, affecting the 18S rRNA maturation process. A higher expression level of the ribosomal stress mediator NAC082 was also detected in the CEVd-infected tomato leaves. Both the alterations in the rRNA processing and the induction of NAC082 correlate with the degree of viroid symptomatology. Taken together, these results suggest that CEVd is responsible for defective ribosome biogenesis in tomato, thereby interfering with the translation machinery and, therefore, causing ribosomal stress.


Assuntos
Lycopersicon esculentum/genética , Doenças das Plantas/genética , Biossíntese de Proteínas , RNA de Plantas/genética , RNA Ribossômico 18S/genética , Ribossomos/metabolismo , Viroides/genética , Citrus/virologia , Interações Hospedeiro-Patógeno/genética , Lycopersicon esculentum/metabolismo , Lycopersicon esculentum/virologia , Biogênese de Organelas , Doenças das Plantas/virologia , Folhas de Planta/genética , Folhas de Planta/metabolismo , Folhas de Planta/virologia , Interferência de RNA , RNA de Plantas/antagonistas & inibidores , RNA de Plantas/metabolismo , RNA Ribossômico 18S/antagonistas & inibidores , RNA Ribossômico 18S/metabolismo , RNA Viral/genética , RNA Viral/metabolismo , Proteínas Ribossômicas/genética , Proteínas Ribossômicas/metabolismo , Ribossomos/genética , Estresse Fisiológico/genética , Viroides/metabolismo , Viroides/patogenicidade
16.
Exp Appl Acarol ; 78(4): 505-520, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31375950

RESUMO

Phytoseiulus persimilis is one of the most important biological control agents of spider mites. Multiple studies have been conducted on factors affecting its reproduction, but limited research on related molecular mechanisms has been carried out. In this study, RNA interference of three genes, ribosomal protein L11 (RpL11), ribosomal protein S2 (RpS2), and transformer-2 (tra-2), to newly emerged females were performed through oral delivery of double-stranded RNA, and knockdown of target genes was verified using qRT-PCR analysis. When RpL11 or RpS2 was interfered, 42 and 30% P. persimilis individuals either laid no egg or had no egg hatched, whereas the remaining females had their oviposition duration reduced by 31.8 and 49.9%, fecundity reduced by 48.1 and 67.8%, and egg hatching rate reduced by 20.4 and 22.4%, respectively. In addition, offspring sex ratios were significantly male biased especially at low fecundities. When tra-2 was interfered, no significant difference in fecundity was detected, but egg hatching rate reduced by 30.6%. This study verified the possibility of RNA interference in Phytoseiidae through oral delivery, and indicated that RpL11 and RpS2 are involved in egg formation, whereas tra-2 is involved in embryo development in P. persimilis. Phytoseiid mites have different sex determination pathways compared to insects. The present study provides data and evidence at molecular biological level for future research on reproduction and sex determination of phytoseiid mites.


Assuntos
Proteínas de Artrópodes/genética , Ácaros/fisiologia , Interferência de RNA , Animais , Proteínas de Artrópodes/metabolismo , Feminino , Técnicas de Silenciamento de Genes , Ácaros/genética , Reprodução/genética , Ribonucleoproteínas/genética , Ribonucleoproteínas/metabolismo , Proteínas Ribossômicas/genética , Proteínas Ribossômicas/metabolismo
17.
BMC Mol Cell Biol ; 20(1): 34, 2019 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-31416416

RESUMO

BACKGROUND: Association of Epstein-Barr virus (EBV) encoded latent gene products with host ribosomal proteins (RPs) has not been fully explored, despite their involvement in the aetiology of several human cancers. To gain an insight into their plausible interactions, we employed a computational approach that encompasses structural alignment, gene ontology analysis, pathway analysis, and molecular docking. RESULTS: In this study, the alignment analysis based on structural similarity allows the prediction of 48 potential interactions between 27 human RPs and the EBV proteins EBNA1, LMP1, LMP2A, and LMP2B. Gene ontology analysis of the putative protein-protein interactions (PPIs) reveals their probable involvement in RNA binding, ribosome biogenesis, metabolic and biosynthetic processes, and gene regulation. Pathway analysis shows their possible participation in viral infection strategies (viral translation), as well as oncogenesis (Wnt and EGFR signalling pathways). Finally, our molecular docking assay predicts the functional interactions of EBNA1 with four RPs individually: EBNA1-eS10, EBNA1-eS25, EBNA1-uL10 and EBNA1-uL11. CONCLUSION: These interactions have never been revealed previously via either experimental or in silico approach. We envisage that the calculated interactions between the ribosomal and EBV proteins herein would provide a hypothetical model for future experimental studies on the functional relationship between ribosomal proteins and EBV infection.


Assuntos
Simulação por Computador , Herpesvirus Humano 4/metabolismo , Proteínas Ribossômicas/metabolismo , Proteínas Virais/metabolismo , Ontologia Genética , Humanos , Simulação de Acoplamento Molecular , Ligação Proteica , Mapas de Interação de Proteínas , Estrutura Secundária de Proteína , Proteínas Ribossômicas/química , Proteínas Virais/química
18.
mSphere ; 4(4)2019 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-31434747

RESUMO

Eukaryotic ribosome biogenesis is an essential cellular process involving tightly coordinated assembly of multiple rRNA and protein components. Much of our understanding of this pathway has come from studies performed with yeast model systems. These studies have identified critical checkpoints in the maturation of the large ribosomal subunit (LSU/60S), one of which is the proper formation and incorporation of the 5S ribonucleoprotein complex (5S RNP). Research on the 5S RNP has identified a complex containing the four proteins L5, L11, Rpf2, and Rrs1 as well as 5S rRNA. Our laboratory has studied the 5S RNP in Trypanosoma brucei, a eukaryotic parasite, and identified the proteins P34 and P37 as essential, parasite-specific members of this complex. We have additionally identified homologues of L5, Rpf2, Rrs1, and 5S rRNA in T. brucei and characterized their roles in this essential process. In this study, we examined the T. brucei homologue of ribosomal protein L11 as a member of the 5S RNP. We showed that TbL11 is essential and that it is important for proper ribosome subunit formation and 60S rRNA processing. Additionally, we identified TbL11 interactions with TbL5 and TbRpf2, as well as novel interactions with the kinetoplast-specific proteins P34 and P37. These findings expand our understanding of a crucial process outside the context of model yeast organisms and highlight differences in an otherwise highly conserved process that could be used to develop future treatments against T. brucei IMPORTANCE The human-pathogenic, eukaryotic parasite Trypanosoma brucei causes human and animal African trypanosomiases. Treatments for T. brucei suffer from numerous hurdles, including adverse side effects and developing resistance. Ribosome biogenesis is one critical process for T. brucei survival that could be targeted for new drug development. A critical checkpoint in ribosome biogenesis is formation of the 5S RNP, which we have shown involves the trypanosome-specific proteins P34 and P37 as well as homologues of Rpf2, Rrs1, and L5. We have identified parasite-specific characteristics of these proteins and involvement in key parts of ribosome biogenesis, making them candidates for future drug development. In this work, we characterized the T. brucei homologue of ribosomal protein L11. We show that it is essential for parasite survival and is involved in ribosome biogenesis and rRNA processing. Furthermore, we identified novel interactions with P34 and P37, characteristics that make this protein a potential target for novel chemotherapeutics.


Assuntos
Biogênese de Organelas , Proteínas de Ligação a RNA/metabolismo , Proteínas Ribossômicas/metabolismo , Ribossomos , Trypanosoma brucei brucei/genética , Ligação Proteica , RNA Ribossômico 5S/genética , Proteínas de Ligação a RNA/genética , Proteínas Ribossômicas/genética , Trypanosoma brucei brucei/metabolismo
19.
Acta Biochim Biophys Sin (Shanghai) ; 51(9): 960-968, 2019 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-31389995

RESUMO

Nα-acetylation is a universal protein modification related to a wide range of physiological processes in eukaryotes and prokaryotes. RimI, an Nα-acetyltransferase in Mycobacterium tuberculosis, is responsible for the acetylation of the α-amino group of the N-terminal residue in the ribosomal protein S18. Despite growing evidence that protein acetylation may be correlated with the pathogenesis of tuberculosis, no structural information is yet available for mechanistically understanding the MtRimI acetylation. To enable structural studies for MtRimI, we constructed a serial of recombinant MtRimI proteins and assessed their biochemical properties. We then chose an optimal construct MtRimIC21A4-153 and expressed and purified the truncated high-quality protein for further biophysical and functional characterizations. The 2D 1H-15N heteronuclear single quantum coherence spectrum of MtRimIC21A4-153 exhibits wider chemical shift dispersion and favorable peak isolation, indicating that MtRimIC21A4-153 is amendable for further structural determination. Moreover, bio-layer interferometry experiments showed that MtRimIC21A4-153 possessed similar micromolar affinity to full-length MtRimI for binding the hexapeptide substrate Ala-Arg-Tyr-Phe-Arg-Arg. Enzyme kinetic assays also exhibited that MtRimIC21A4-153 had almost identical enzymatic activity to MtRimI, indicating insignificant influence of the recombinant variations on enzymatic functions. Furthermore, binding sites of the peptide were predicted by molecular docking approach, suggesting that this substrate binds to MtRimI primarily through electrostatic and hydrogen bonding interactions. Our results lay a foundation for the further structural determination and dynamics detection of MtRimI.


Assuntos
Acetiltransferases/química , Proteínas de Bactérias/química , Mycobacterium tuberculosis/enzimologia , Proteínas Recombinantes/química , Acetilação , Sítios de Ligação , Simulação de Acoplamento Molecular , Processamento de Proteína Pós-Traducional , Proteínas Ribossômicas/metabolismo , Especificidade por Substrato
20.
Methods Mol Biol ; 1934: 293-307, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31256386

RESUMO

A wide variety of posttranslational modifications of expressed proteins are known to occur in living organisms (Krishna R, Wold F. Post-translational modification of proteins. In: Meister A (ed) Advances in enzymology and related areas of molecular biology. Wiley, New York, 1993, pp 265-296). Although their presence in an organism cannot be predicted from the genome, these modifications can play critical roles in protein structure and function. The identification of posttranslational modifications is critical to our understanding of the functions of proteins involved in important biological pathways and mass spectrometry offers a fast, accurate method for observing them. A combined top-down/bottom-up approach can be used for identification and localization of posttranslational modifications of ribosomal proteins. This chapter describes procedures for analyzing Escherichia coli ribosomal proteins and their modifications by matrix-assisted laser desorption ionization-time-of-flight (MALDI-TOF) mass spectrometry. It also covers the analysis of gram-negative Caulobacter crescentus and gram-positive Bacillus subtilis ribosomal proteins by electrospray quadrupole time-of-flight (ESI-QTOF) mass spectrometry. Confirmation of the occurrence and localization of PTMs is obtained through mass spectrometric analysis of tryptic peptides.


Assuntos
Proteínas de Bactérias/metabolismo , Proteínas Ribossômicas/metabolismo , Acetilação , Proteínas de Bactérias/química , Cromatografia Líquida , Metilação , Processamento de Proteína Pós-Traducional , Proteômica/métodos , Proteínas Ribossômicas/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Espectrometria de Massas em Tandem
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