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[PMID]:28694328
[Au] Autor:Niland CN; Anderson DR; Jankowsky E; Harris ME
[Ad] Endereço:Department of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, USA.
[Ti] Título:The contribution of the C5 protein subunit of ribonuclease P to specificity for precursor tRNA is modulated by proximal 5' leader sequences.
[So] Source:RNA;23(10):1502-1511, 2017 Oct.
[Is] ISSN:1469-9001
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Recognition of RNA by RNA processing enzymes and RNA binding proteins often involves cooperation between multiple subunits. However, the interdependent contributions of RNA and protein subunits to molecular recognition by ribonucleoproteins are relatively unexplored. RNase P is an endonuclease that removes 5' leaders from precursor tRNAs and functions in bacteria as a dimer formed by a catalytic RNA subunit (P RNA) and a protein subunit (C5 in ). The P RNA subunit contacts the tRNA body and proximal 5' leader sequences [N(-1) and N(-2)] while C5 binds distal 5' leader sequences [N(-3) to N(-6)]. To determine whether the contacts formed by P RNA and C5 contribute independently to specificity or exhibit cooperativity or anti-cooperativity, we compared the relative / values for all possible combinations of the six proximal 5' leader nucleotides ( = 4096) for processing by the P RNA subunit alone and by the RNase P holoenzyme. We observed that while the P RNA subunit shows specificity for 5' leader nucleotides N(-2) and N(-1), the presence of the C5 protein reduces the contribution of P RNA to specificity, but changes specificity at N(-2) and N(-3). The results reveal that the contribution of C5 protein to RNase P processing is controlled by the identity of N(-2) in the pre-tRNA 5' leader. The data also clearly show that pairing of the 5' leader with the 3' ACCA of tRNA acts as an anti-determinant for RNase P cleavage. Comparative analysis of genomically encoded tRNAs reveals that both anti-determinants are subject to negative selection in vivo.
[Mh] Termos MeSH primário: Proteínas de Escherichia coli/metabolismo
Precursores de RNA/metabolismo
RNA de Transferência/metabolismo
Ribonuclease P/metabolismo
[Mh] Termos MeSH secundário: Proteínas de Escherichia coli/química
Nucleotídeos/química
Nucleotídeos/metabolismo
Precursores de RNA/química
RNA de Transferência/química
RNA de Transferência de Metionina/química
RNA de Transferência de Metionina/metabolismo
Ribonuclease P/química
Especificidade por Substrato
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Escherichia coli Proteins); 0 (Nucleotides); 0 (RNA Precursors); 0 (RNA, Transfer, Met); 9014-25-9 (RNA, Transfer); EC 3.1.26.5 (Ribonuclease P); EC 3.1.26.5 (ribonuclease P, E coli)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171019
[Lr] Data última revisão:
171019
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170712
[St] Status:MEDLINE
[do] DOI:10.1261/rna.056408.116


  2 / 952 MEDLINE  
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[PMID]:28472312
[Au] Autor:Kawarada L; Suzuki T; Ohira T; Hirata S; Miyauchi K; Suzuki T
[Ad] Endereço:Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
[Ti] Título:ALKBH1 is an RNA dioxygenase responsible for cytoplasmic and mitochondrial tRNA modifications.
[So] Source:Nucleic Acids Res;45(12):7401-7415, 2017 Jul 07.
[Is] ISSN:1362-4962
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:ALKBH1 is a 2-oxoglutarate- and Fe2+-dependent dioxygenase responsible for multiple cellular functions. Here, we show that ALKBH1 is involved in biogenesis of 5-hydroxymethyl-2΄-O-methylcytidine (hm5Cm) and 5-formyl-2΄-O-methylcytidine (f5Cm) at the first position (position 34) of anticodon in cytoplasmic tRNALeu, as well as f5C at the same position in mitochondrial tRNAMet. Because f5C34 of mitochondrial tRNAMet is essential for translation of AUA, a non-universal codon in mammalian mitochondria, ALKBH1-knockout cells exhibited a strong reduction in mitochondrial translation and reduced respiratory complex activities, indicating that f5C34 formation mediated by ALKBH1 is required for efficient mitochondrial functions. We reconstituted formation of f5C34 on mitochondrial tRNAMetin vitro, and found that ALKBH1 first hydroxylated m5C34 to form hm5C34, and then oxidized hm5C34 to form f5C34. Moreover, we found that the frequency of 1-methyladenosine (m1A) in two mitochondrial tRNAs increased in ALKBH1-knockout cells, indicating that ALKBH1 also has demethylation activity toward m1A in mt-tRNAs. Based on these results, we conclude that nuclear and mitochondrial ALKBH1 play distinct roles in tRNA modification.
[Mh] Termos MeSH primário: Homólogo AlkB 1 da Histona H2a Dioxigenase/genética
Citidina/análogos & derivados
Biossíntese de Proteínas
RNA de Transferência de Metionina/genética
[Mh] Termos MeSH secundário: Homólogo AlkB 1 da Histona H2a Dioxigenase/deficiência
Anticódon/química
Anticódon/metabolismo
Sequência de Bases
Sistemas CRISPR-Cas
Citidina/metabolismo
Citosol/metabolismo
Técnicas de Inativação de Genes
Teste de Complementação Genética
Células HEK293
Seres Humanos
Metiltransferases/genética
Metiltransferases/metabolismo
Mitocôndrias/metabolismo
Conformação de Ácido Nucleico
Oxirredução
Fosforilação Oxidativa
RNA de Transferência de Metionina/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (2'-O-methyl-5-formylcytidine); 0 (Anticodon); 0 (RNA, Transfer, Met); 148608-53-1 (5-formylcytidine); 5CSZ8459RP (Cytidine); EC 1.14.11.33 (ALKBH1 protein, human); EC 1.14.11.33 (AlkB Homolog 1, Histone H2a Dioxygenase); EC 2.1.1.- (Methyltransferases); EC 2.1.1.- (NSUN3 protein, human)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171017
[Lr] Data última revisão:
171017
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170505
[St] Status:MEDLINE
[do] DOI:10.1093/nar/gkx354


  3 / 952 MEDLINE  
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[PMID]:28369041
[Au] Autor:Jurenas D; Chatterjee S; Konijnenberg A; Sobott F; Droogmans L; Garcia-Pino A; Van Melderen L
[Ad] Endereço:Laboratoire de Génétique et Physiologie Bactérienne, Université Libre de Bruxelles, Gosselies, Belgium.
[Ti] Título:AtaT blocks translation initiation by N-acetylation of the initiator tRNA .
[So] Source:Nat Chem Biol;13(6):640-646, 2017 Jun.
[Is] ISSN:1552-4469
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Toxin-antitoxin (TA) loci are prevalent in bacterial genomes. They are suggested to play a central role in dormancy and persister states. Under normal growth conditions, TA toxins are neutralized by their cognate antitoxins, and under stress conditions, toxins are freed and inhibit essential cellular processes using a variety of mechanisms. Here we characterize ataR-ataT, a novel TA system, from enterohemorrhagic Escherichia coli. We show that the toxin AtaT is a GNAT family enzyme that transfers an acetyl group from acetyl coenzyme A to the amine group of the methionyl aminoacyl moiety of initiator tRNA. AtaT specifically modifies Met-tRNA , but no other aminoacyl-tRNAs, including the elongator Met-tRNA . We demonstrate that once acetylated, AcMet-tRNA fails to interact with initiation factor-2 (IF2), resulting in disruption of the translation initiation complex. This work reveals a new mechanism of translation inhibition and confirms Met-tRNA as a prime target to efficiently block cell growth.
[Mh] Termos MeSH primário: Aminoácido N-Acetiltransferase/metabolismo
Escherichia coli
Regulação da Expressão Gênica/genética
RNA de Transferência de Metionina/metabolismo
[Mh] Termos MeSH secundário: Acetilação
Eletroforese em Gel Bidimensional
Modelos Biológicos
Biossíntese de Proteínas
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (RNA, Transfer, Met); EC 2.3.1.1 (Amino-Acid N-Acetyltransferase)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170922
[Lr] Data última revisão:
170922
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170404
[St] Status:MEDLINE
[do] DOI:10.1038/nchembio.2346


  4 / 952 MEDLINE  
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[PMID]:28259969
[Au] Autor:Yu SS; Du JM; Tang ZD; He ZF
[Ad] Endereço:Department of Biology, School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, Zhejiang 325035, P.R. China.
[Ti] Título:Molecular characterization of mitochondrial transferRNAGln and transferRNAMet A4401G mutations in a Chinese family with hypertension.
[So] Source:Mol Med Rep;15(4):1832-1836, 2017 Apr.
[Is] ISSN:1791-3004
[Cp] País de publicação:Greece
[La] Idioma:eng
[Ab] Resumo:Mutations in mitochondrial (mt)transfer (t)RNA (mt­tRNA) have been reported to serve important roles in hypertension. To determine the underlying molecular mechanisms of mt­tRNA mutations in hypertension, the present study screened for mt­tRNA mutations in a Chinese family with a high incidence of essential hypertension. Sequence analysis of the mt­tRNA genes in this family revealed the presence of an A4401G mutation in the glycine­and methionine­tRNA genes, and a G5821A mutation in the cysteine­tRNA (tRNACys) gene. The G5821A mutation was located at a position conserved in various species, and disrupted G6­C67 base­pairing. It was hypothesized that the G5821A mutation may decrease the baseline expression levels of tRNACys, and consequently result in failure of tRNA metabolism. The A4401G mutation was reported to cause the mitochondrial dysfunction responsible for hypertension. Thus, the combination of G5821A and A4401G mutations may contribute to the high incidence of hypertension in this family. Mt­tRNA mutations may serve as potential biomarkers for hypertension.
[Mh] Termos MeSH primário: Hipertensão/genética
Mitocôndrias/genética
Mutação Puntual
RNA de Transferência de Glutamina/genética
RNA de Transferência de Metionina/genética
[Mh] Termos MeSH secundário: Grupo com Ancestrais do Continente Asiático/genética
Sequência de Bases
China/epidemiologia
Hipertensão Essencial
Feminino
Seres Humanos
Hipertensão/epidemiologia
Hipertensão/patologia
Masculino
Meia-Idade
Linhagem
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (RNA, Transfer, Gln); 0 (RNA, Transfer, Met)
[Em] Mês de entrada:1705
[Cu] Atualização por classe:171116
[Lr] Data última revisão:
171116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170306
[St] Status:MEDLINE
[do] DOI:10.3892/mmr.2017.6216


  5 / 952 MEDLINE  
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[PMID]:28143889
[Au] Autor:Monestier A; Aleksandrov A; Coureux PD; Panvert M; Mechulam Y; Schmitt E
[Ad] Endereço:Laboratoire de Biochimie, Ecole polytechnique, CNRS, Université Paris-Saclay, 91128 Palaiseau cedex, France.
[Ti] Título:The structure of an tRNA A -U variant shows an unusual conformation of the A -U base pair.
[So] Source:RNA;23(5):673-682, 2017 May.
[Is] ISSN:1469-9001
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Translation initiation in eukaryotes and archaea involves a methionylated initiator tRNA delivered to the ribosome in a ternary complex with e/aIF2 and GTP. Eukaryotic and archaeal initiator tRNAs contain a highly conserved A -U base pair at the top of the acceptor stem. The importance of this base pair to discriminate initiator tRNAs from elongator tRNAs has been established previously using genetics and biochemistry. However, no structural data illustrating how the A -U base pair participates in the accurate selection of the initiator tRNAs by the translation initiation systems are available. Here, we describe the crystal structure of a mutant initiator tRNA A -U , aminoacylated with methionine, in which the C :A mismatch at the end of the tRNA acceptor stem has been changed to an A -U base pair. Sequence alignments show that the mutant tRNA is a good mimic of archaeal initiator tRNAs. The crystal structure, determined at 2.8 Å resolution, shows that the A -U pair adopts an unusual arrangement. A is in a conformation and forms a single H-bond interaction with U This interaction requires protonation of the N1 atom of A Moreover, the 5' phosphoryl group folds back into the major groove of the acceptor stem and interacts with the N7 atom of G A possible role of this unusual geometry of the A -U pair in the recognition of the initiator tRNA by its partners during eukaryotic and archaeal translation initiation is discussed.
[Mh] Termos MeSH primário: Escherichia coli/genética
RNA de Transferência de Metionina/química
[Mh] Termos MeSH secundário: Anticódon
Pareamento de Bases
Escherichia coli/metabolismo
Modelos Moleculares
Simulação de Dinâmica Molecular
RNA Arqueal/química
RNA Bacteriano/química
RNA Bacteriano/metabolismo
RNA de Transferência de Metionina/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Anticodon); 0 (RNA, Archaeal); 0 (RNA, Bacterial); 0 (RNA, Transfer, Met)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170609
[Lr] Data última revisão:
170609
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170202
[St] Status:MEDLINE
[do] DOI:10.1261/rna.057877.116


  6 / 952 MEDLINE  
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[PMID]:28082677
[Au] Autor:Zaganelli S; Rebelo-Guiomar P; Maundrell K; Rozanska A; Pierredon S; Powell CA; Jourdain AA; Hulo N; Lightowlers RN; Chrzanowska-Lightowlers ZM; Minczuk M; Martinou JC
[Ad] Endereço:From the Department of Cell Biology, University of Geneva, 30 quai Ernest-Ansermet, 1211 Genève 4, Switzerland.
[Ti] Título:The Pseudouridine Synthase RPUSD4 Is an Essential Component of Mitochondrial RNA Granules.
[So] Source:J Biol Chem;292(11):4519-4532, 2017 Mar 17.
[Is] ISSN:1083-351X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Mitochondrial gene expression is a fundamental process that is largely dependent on nuclear-encoded proteins. Several steps of mitochondrial RNA processing and maturation, including RNA post-transcriptional modification, appear to be spatially organized into distinct foci, which we have previously termed mitochondrial RNA granules (MRGs). Although an increasing number of proteins have been localized to MRGs, a comprehensive analysis of the proteome of these structures is still lacking. Here, we have applied a microscopy-based approach that has allowed us to identify novel components of the MRG proteome. Among these, we have focused our attention on RPUSD4, an uncharacterized mitochondrial putative pseudouridine synthase. We show that RPUSD4 depletion leads to a severe reduction of the steady-state level of the 16S mitochondrial (mt) rRNA with defects in the biogenesis of the mitoribosome large subunit and consequently in mitochondrial translation. We report that RPUSD4 binds 16S mt-rRNA, mt-tRNA , and mt-tRNA , and we demonstrate that it is responsible for pseudouridylation of the latter. These data provide new insights into the relevance of RNA pseudouridylation in mitochondrial gene expression.
[Mh] Termos MeSH primário: Transferases Intramoleculares/metabolismo
RNA/metabolismo
[Mh] Termos MeSH secundário: Linhagem Celular
Seres Humanos
Transferases Intramoleculares/análise
Transferases Intramoleculares/genética
Mitocôndrias/genética
Mitocôndrias/metabolismo
Proteínas Mitocondriais/metabolismo
Transporte Proteico
Interferência de RNA
RNA Ribossômico 16S/metabolismo
RNA Interferente Pequeno/genética
RNA de Transferência de Metionina/metabolismo
RNA de Transferência de Fenilalanina/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Mitochondrial Proteins); 0 (RNA, Ribosomal, 16S); 0 (RNA, Small Interfering); 0 (RNA, Transfer, Met); 0 (RNA, Transfer, Phe); 0 (RNA, mitochondrial); 63231-63-0 (RNA); EC 5.4.- (Intramolecular Transferases); EC 5.4.99.- (pseudouridine synthases)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170606
[Lr] Data última revisão:
170606
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170114
[St] Status:MEDLINE
[do] DOI:10.1074/jbc.M116.771105


  7 / 952 MEDLINE  
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[PMID]:27986852
[Au] Autor:López-Alonso JP; Fabbretti A; Kaminishi T; Iturrioz I; Brandi L; Gil-Carton D; Gualerzi CO; Fucini P; Connell SR
[Ad] Endereço:Structural Biology Unit, CIC bioGUNE, Parque Tecnológico de Bizkaia, 48160 Derio, Bizkaia, Spain.
[Ti] Título:Structure of a 30S pre-initiation complex stalled by GE81112 reveals structural parallels in bacterial and eukaryotic protein synthesis initiation pathways.
[So] Source:Nucleic Acids Res;45(4):2179-2187, 2017 Feb 28.
[Is] ISSN:1362-4962
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:In bacteria, the start site and the reading frame of the messenger RNA are selected by the small ribosomal subunit (30S) when the start codon, typically an AUG, is decoded in the P-site by the initiator tRNA in a process guided and controlled by three initiation factors. This process can be efficiently inhibited by GE81112, a natural tetrapeptide antibiotic that is highly specific toward bacteria. Here GE81112 was used to stabilize the 30S pre-initiation complex and obtain its structure by cryo-electron microscopy. The results obtained reveal the occurrence of changes in both the ribosome conformation and initiator tRNA position that may play a critical role in controlling translational fidelity. Furthermore, the structure highlights similarities with the early steps of initiation in eukaryotes suggesting that shared structural features guide initiation in all kingdoms of life.
[Mh] Termos MeSH primário: Iniciação Traducional da Cadeia Peptídica
RNA Mensageiro/genética
RNA de Transferência de Metionina/genética
Subunidades Ribossômicas Menores de Bactérias/metabolismo
[Mh] Termos MeSH secundário: Sítios de Ligação
Escherichia coli/genética
Escherichia coli/metabolismo
Células Eucarióticas/metabolismo
Modelos Moleculares
Conformação Molecular
Fatores de Iniciação em Procariotos/química
Fatores de Iniciação em Procariotos/metabolismo
Biossíntese de Proteínas/genética
RNA Mensageiro/química
RNA Mensageiro/metabolismo
RNA de Transferência de Metionina/química
RNA de Transferência de Metionina/metabolismo
Subunidades Ribossômicas Maiores de Bactérias/química
Subunidades Ribossômicas Maiores de Bactérias/metabolismo
Subunidades Ribossômicas Menores de Bactérias/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Prokaryotic Initiation Factors); 0 (RNA, Messenger); 0 (RNA, Transfer, Met)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171002
[Lr] Data última revisão:
171002
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161218
[St] Status:MEDLINE
[do] DOI:10.1093/nar/gkw1251


  8 / 952 MEDLINE  
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[PMID]:27983482
[Au] Autor:Cai Y; Chandrangsu P; Gaballa A; Helmann JD
[Ad] Endereço:2​Department of Soil Science, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, PR China 1​Department of Microbiology, Cornell University, Ithaca, NY 14853, USA.
[Ti] Título:Lack of formylated methionyl-tRNA has pleiotropic effects on Bacillus subtilis.
[So] Source:Microbiology;163(2):185-196, 2017 Feb.
[Is] ISSN:1465-2080
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Bacteria initiate translation using a modified amino acid, N-formylmethionine (fMet), adapted specifically for this function. Most proteins are processed co-translationally by peptide deformylase (PDF) to remove this modification. Although PDF activity is essential in WT cells and is the target of the antibiotic actinonin, bypass mutations in the fmt gene that eliminate the formylation of Met-tRNAMet render PDF dispensable. The extent to which the emergence of fmt bypass mutations might compromise the therapeutic utility of actinonin is determined, in part, by the effects of these bypass mutations on fitness. Here, we characterize the phenotypic consequences of an fmt null mutation in the model organism Bacillus subtilis. An fmt null mutant is defective for several post-exponential phase adaptive programmes including antibiotic resistance, biofilm formation, swarming and swimming motility and sporulation. In addition, a survey of well-characterized stress responses reveals an increased sensitivity to metal ion excess and oxidative stress. These diverse phenotypes presumably reflect altered synthesis or stability of key proteins involved in these processes.
[Mh] Termos MeSH primário: Amidoidrolases/genética
Bacillus subtilis/crescimento & desenvolvimento
N-Formilmetionina/metabolismo
Biossíntese de Proteínas/genética
RNA de Transferência de Metionina/genética
[Mh] Termos MeSH secundário: Amidoidrolases/metabolismo
Antibacterianos/farmacologia
Bacillus subtilis/genética
Bacillus subtilis/metabolismo
Biofilmes/crescimento & desenvolvimento
Peróxido de Hidrogênio/farmacologia
Ácidos Hidroxâmicos/farmacologia
Estresse Oxidativo/fisiologia
Paraquat/farmacologia
Biossíntese de Proteínas/fisiologia
Aldeído Pirúvico/farmacologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Anti-Bacterial Agents); 0 (Hydroxamic Acids); 0 (RNA, Transfer, Met); 4289-98-9 (N-Formylmethionine); 722KLD7415 (Pyruvaldehyde); BBX060AN9V (Hydrogen Peroxide); EC 3.5.- (Amidohydrolases); EC 3.5.1.88 (peptide deformylase); P18SPA8N0K (actinonin); PLG39H7695 (Paraquat)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170926
[Lr] Data última revisão:
170926
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161217
[St] Status:MEDLINE
[do] DOI:10.1099/mic.0.000413


  9 / 952 MEDLINE  
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[PMID]:27899592
[Au] Autor:Kwon OS; An S; Kim E; Yu J; Hong KY; Lee JS; Jang SK
[Ad] Endereço:Molecular Virology Laboratory, POSTECH Biotech Center, Department of Life Sciences, Pohang University of Science and Technology, Pohang, Korea.
[Ti] Título:An mRNA-specific tRNAi carrier eIF2A plays a pivotal role in cell proliferation under stress conditions: stress-resistant translation of c-Src mRNA is mediated by eIF2A.
[So] Source:Nucleic Acids Res;45(1):296-310, 2017 Jan 09.
[Is] ISSN:1362-4962
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:c-Src, a non-receptor protein tyrosine kinase, activates NF-κB and STAT3, which in turn triggers the transcription of anti-apoptosis- and cell cycle-related genes. c-Src protein regulates cell proliferation, cell motility and programmed cell death. And the elevated level of activated c-Src protein is related with solid tumor generation. Translation of c-Src mRNA is directed by an IRES element which mediates persistent translation under stress conditions when translation of most mRNAs is inhibited by a phosphorylation of the alpha subunit of eIF2 carrying the initiator tRNA (tRNA ) to 40S ribosomal subunit under normal conditions. The molecular basis of the stress-resistant translation of c-Src mRNA remained to be elucidated. Here, we report that eIF2A, an alternative tRNA carrier, is responsible for the stress-resistant translation of c-Src mRNA. eIF2A facilitates tRNA loading onto the 40S ribosomal subunit in a c-Src mRNA-dependent manner. And a direct interaction between eIF2A and a stem-loop structure (SL I) in the c-Src IRES is required for the c-Src IRES-dependent translation under stress conditions but not under normal conditions. Finally, we showed that the eIF2A-dependent translation of c-Src mRNA plays a pivotal role in cell proliferation under stress conditions.
[Mh] Termos MeSH primário: Fator de Iniciação 2 em Eucariotos/genética
Hepatócitos/metabolismo
Biossíntese de Proteínas
RNA de Transferência de Metionina/genética
RNA/genética
Quinases da Família src/genética
[Mh] Termos MeSH secundário: Biotinilação
Linhagem Celular Tumoral
Proliferação Celular/efeitos dos fármacos
Fator de Iniciação 2 em Eucariotos/metabolismo
Regulação da Expressão Gênica
Células HEK293
Hepatócitos/citologia
Hepatócitos/efeitos dos fármacos
Seres Humanos
NF-kappa B/genética
NF-kappa B/metabolismo
Conformação de Ácido Nucleico
Fosforilação
RNA/metabolismo
RNA de Transferência de Metionina/metabolismo
Elementos de Resposta
Subunidades Ribossômicas Menores de Eucariotos/química
Subunidades Ribossômicas Menores de Eucariotos/metabolismo
Fator de Transcrição STAT3/genética
Fator de Transcrição STAT3/metabolismo
Estresse Fisiológico
Tunicamicina/farmacologia
Quinases da Família src/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Eukaryotic Initiation Factor-2); 0 (NF-kappa B); 0 (RNA, Transfer, Met); 0 (STAT3 Transcription Factor); 0 (STAT3 protein, human); 11089-65-9 (Tunicamycin); 63231-63-0 (RNA); EC 2.7.10.2 (CSK tyrosine-protein kinase); EC 2.7.10.2 (src-Family Kinases)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170606
[Lr] Data última revisão:
170606
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161201
[St] Status:MEDLINE
[do] DOI:10.1093/nar/gkw1117


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[PMID]:27927177
[Au] Autor:Ardell DH; Hou YM
[Ad] Endereço:Program in Quantitative and Systems Biology, University of California, 5200 North Lake Road, CA, 95343, Merced, USA. dardell@ucmerced.edu.
[Ti] Título:Initiator tRNA genes template the 3' CCA end at high frequencies in bacteria.
[So] Source:BMC Genomics;17(1):1003, 2016 12 08.
[Is] ISSN:1471-2164
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: While the CCA sequence at the mature 3' end of tRNAs is conserved and critical for translational function, a genetic template for this sequence is not always contained in tRNA genes. In eukaryotes and Archaea, the CCA ends of tRNAs are synthesized post-transcriptionally by CCA-adding enzymes. In Bacteria, tRNA genes template CCA sporadically. RESULTS: In order to understand the variation in how prokaryotic tRNA genes template CCA, we re-annotated tRNA genes in tRNAdb-CE database version 0.8. Among 132,129 prokaryotic tRNA genes, initiator tRNA genes template CCA at the highest average frequency (74.1%) over all functional classes except selenocysteine and pyrrolysine tRNA genes (88.1% and 100% respectively). Across bacterial phyla and a wide range of genome sizes, many lineages exist in which predominantly initiator tRNA genes template CCA. Convergent and parallel retention of CCA templating in initiator tRNA genes evolved in independent histories of reductive genome evolution in Bacteria. Also, in a majority of cyanobacterial and actinobacterial genera, predominantly initiator tRNA genes template CCA. We also found that a surprising fraction of archaeal tRNA genes template CCA. CONCLUSIONS: We suggest that cotranscriptional synthesis of initiator tRNA CCA 3' ends can complement inefficient processing of initiator tRNA precursors, "bootstrap" rapid initiation of protein synthesis from a non-growing state, or contribute to an increase in cellular growth rates by reducing overheads of mass and energy to maintain nonfunctional tRNA precursor pools. More generally, CCA templating in structurally non-conforming tRNA genes can afford cells robustness and greater plasticity to respond rapidly to environmental changes and stimuli.
[Mh] Termos MeSH primário: Bactérias/genética
Precursores de RNA/metabolismo
[Mh] Termos MeSH secundário: Anticódon
Archaea/genética
Pareamento de Bases
Sequência de Bases
Bases de Dados Genéticas
Genes Arqueais
Genes Bacterianos
Precursores de RNA/química
RNA de Transferência de Metionina/química
RNA de Transferência de Metionina/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.; RESEARCH SUPPORT, N.I.H., EXTRAMURAL
[Nm] Nome de substância:
0 (Anticodon); 0 (RNA Precursors); 0 (RNA, Transfer, Met)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:171119
[Lr] Data última revisão:
171119
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161209
[St] Status:MEDLINE



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