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[PMID]:28977480
[Au] Autor:Peralta-Castro A; Baruch-Torres N; Brieba LG
[Ad] Endereço:Laboratorio Nacional de Genómica para la Biodiversidad, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal 629, Irapuato, Guanajuato, CP 36821, México.
[Ti] Título:Plant organellar DNA primase-helicase synthesizes RNA primers for organellar DNA polymerases using a unique recognition sequence.
[So] Source:Nucleic Acids Res;45(18):10764-10774, 2017 Oct 13.
[Is] ISSN:1362-4962
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:DNA primases recognize single-stranded DNA (ssDNA) sequences to synthesize RNA primers during lagging-strand replication. Arabidopsis thaliana encodes an ortholog of the DNA primase-helicase from bacteriophage T7, dubbed AtTwinkle, that localizes in chloroplasts and mitochondria. Herein, we report that AtTwinkle synthesizes RNA primers from a 5'-(G/C)GGA-3' template sequence. Within this sequence, the underlined nucleotides are cryptic, meaning that they are essential for template recognition but are not instructional during RNA synthesis. Thus, in contrast to all primases characterized to date, the sequence recognized by AtTwinkle requires two nucleotides (5'-GA-3') as a cryptic element. The divergent zinc finger binding domain (ZBD) of the primase module of AtTwinkle may be responsible for template sequence recognition. During oligoribonucleotide synthesis, AtTwinkle shows a strong preference for rCTP as its initial ribonucleotide and a moderate preference for rGMP or rCMP incorporation during elongation. RNA products synthetized by AtTwinkle are efficiently used as primers for plant organellar DNA polymerases. In sum, our data strongly suggest that AtTwinkle primes organellar DNA polymerases during lagging strand synthesis in plant mitochondria and chloroplast following a primase-mediated mechanism. This mechanism contrasts to lagging-strand DNA replication in metazoan mitochondria, in which transcripts synthesized by mitochondrial RNA polymerase prime mitochondrial DNA polymerase γ.
[Mh] Termos MeSH primário: Proteínas de Arabidopsis/metabolismo
DNA Helicases/metabolismo
DNA Primase/metabolismo
DNA Polimerase Dirigida por DNA/metabolismo
Enzimas Multifuncionais/metabolismo
RNA/biossíntese
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Proteínas de Arabidopsis/química
Proteínas de Arabidopsis/genética
Sequência de Bases
Proteínas de Cloroplastos/química
Proteínas de Cloroplastos/genética
Proteínas de Cloroplastos/metabolismo
Sequência Conservada
DNA Helicases/química
DNA Helicases/genética
DNA Primase/química
DNA Primase/genética
DNA de Cadeia Simples/química
Proteínas Mitocondriais/química
Proteínas Mitocondriais/genética
Proteínas Mitocondriais/metabolismo
Enzimas Multifuncionais/química
Enzimas Multifuncionais/genética
Ligação Proteica
Ribonucleotídeos/biossíntese
Moldes Genéticos
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Arabidopsis Proteins); 0 (Chloroplast Proteins); 0 (DNA, Single-Stranded); 0 (Mitochondrial Proteins); 0 (Multifunctional Enzymes); 0 (RNA primers); 0 (Ribonucleotides); 0 (Twinkle protein, Arabidopsis); 63231-63-0 (RNA); EC 2.7.7.- (DNA Primase); EC 2.7.7.7 (DNA-Directed DNA Polymerase); EC 3.6.4.- (DNA Helicases)
[Em] Mês de entrada:1711
[Cu] Atualização por classe:171107
[Lr] Data última revisão:
171107
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171005
[St] Status:MEDLINE
[do] DOI:10.1093/nar/gkx745


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[PMID]:28911121
[Au] Autor:Agudo R; Calvo PA; Martínez-Jiménez MI; Blanco L
[Ad] Endereço:Centro de Biología Molecular 'Severo Ochoa' (CSIC-UAM), Cantoblanco, E-28049 Madrid, Spain.
[Ti] Título:Engineering human PrimPol into an efficient RNA-dependent-DNA primase/polymerase.
[So] Source:Nucleic Acids Res;45(15):9046-9058, 2017 Sep 06.
[Is] ISSN:1362-4962
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:We have developed a straightforward fluorometric assay to measure primase-polymerase activity of human PrimPol (HsPrimPol). The sensitivity of this procedure uncovered a novel RNA-dependent DNA priming-polymerization activity (RdDP) of this enzyme. In an attempt to enhance HsPrimPol RdDP activity, we constructed a smart mutant library guided by prior sequence-function analysis, and tested this library in an adapted screening platform of our fluorometric assay. After screening less than 500 variants, we found a specific HsPrimPol mutant, Y89R, which displays 10-fold higher RdDP activity than the wild-type enzyme. The improvement of RdDP activity in the Y89R variant was due mainly to an increased in the stabilization of the preternary complex (protein:template:incoming nucleotide), a specific step preceding dimer formation. Finally, in support of the biotechnological potential of PrimPol as a DNA primer maker during reverse transcription, mutant Y89R HsPrimPol rendered up to 17-fold more DNA than with random hexamer primers.
[Mh] Termos MeSH primário: Substituição de Aminoácidos
Bioensaio
DNA Primase/genética
DNA Polimerase Dirigida por DNA/genética
Enzimas Multifuncionais/genética
Engenharia de Proteínas/métodos
DNA Polimerase Dirigida por RNA/genética
RNA/genética
[Mh] Termos MeSH secundário: Arginina/química
Arginina/metabolismo
Clonagem Molecular
DNA Primase/metabolismo
Primers do DNA/síntese química
Primers do DNA/química
DNA Polimerase Dirigida por DNA/metabolismo
Escherichia coli/genética
Escherichia coli/metabolismo
Corantes Fluorescentes/química
Fluorometria/métodos
Expressão Gênica
Biblioteca Gênica
Seres Humanos
Enzimas Multifuncionais/metabolismo
Mutação
Oligonucleotídeos/química
Oligonucleotídeos/metabolismo
Compostos Orgânicos/química
Ligação Proteica
Multimerização Proteica
RNA/metabolismo
DNA Polimerase Dirigida por RNA/metabolismo
Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos
Tirosina/química
Tirosina/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (DNA Primers); 0 (Fluorescent Dyes); 0 (Multifunctional Enzymes); 0 (Oligonucleotides); 0 (Organic Chemicals); 163795-75-3 (SYBR Green I); 42HK56048U (Tyrosine); 63231-63-0 (RNA); 94ZLA3W45F (Arginine); EC 2.7.7.- (DNA Primase); EC 2.7.7.- (PrimPol protein, human); EC 2.7.7.49 (RNA-Directed DNA Polymerase); EC 2.7.7.7 (DNA-Directed DNA Polymerase)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171012
[Lr] Data última revisão:
171012
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170916
[St] Status:MEDLINE
[do] DOI:10.1093/nar/gkx633


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[PMID]:28902865
[Au] Autor:Boldinova EO; Stojkovic G; Khairullin R; Wanrooij S; Makarova AV
[Ad] Endereço:Institute of Molecular Genetics of Russian Academy of Sciences, Kurchatov sq. 2, Moscow, Russia.
[Ti] Título:Optimization of the expression, purification and polymerase activity reaction conditions of recombinant human PrimPol.
[So] Source:PLoS One;12(9):e0184489, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Human PrimPol is a DNA primase/polymerase involved in DNA damage tolerance and prevents nuclear genome instability. PrimPol is also localized to the mitochondria, but its precise function in mitochondrial DNA maintenance has remained elusive. PrimPol works both as a translesion (TLS) polymerase and as the primase that restarts DNA replication after a lesion. However, the observed biochemical activities of PrimPol vary considerably between studies as a result of different reaction conditions used. To reveal the effects of reaction composition on PrimPol DNA polymerase activity, we tested the polymerase activity in the presence of various buffer agents, salt concentrations, pH values and metal cofactors. Additionally, the enzyme stability was analyzed under various conditions. We demonstrate that the reaction buffer with pH 6-6.5, low salt concentrations and 3 mM Mg2+ or 0.3-3 mM Mn2+ cofactor ions supports the highest DNA polymerase activity of human PrimPol in vitro. The DNA polymerase activity of PrimPol was found to be stable after multiple freeze-thaw cycles and prolonged protein incubation on ice. However, rapid heat-inactivation of the enzyme was observed at 37ºC. We also for the first time describe the purification of human PrimPol from a human cell line and compare the benefits of this approach to the expression in Escherichia coli and in Saccharomyces cerevisiae cells. Our results show that active PrimPol can be purified from E. coli and human suspension cell line in high quantities and that the activity of the purified enzyme is similar in both expression systems. Conversely, the yield of full-length protein expressed in S. cerevisiae was considerably lower and this system is therefore not recommended for expression of full-length recombinant human PrimPol.
[Mh] Termos MeSH primário: DNA Primase/genética
DNA Primase/isolamento & purificação
DNA Polimerase Dirigida por DNA/genética
DNA Polimerase Dirigida por DNA/isolamento & purificação
Enzimas Multifuncionais/genética
Enzimas Multifuncionais/isolamento & purificação
Reação em Cadeia da Polimerase/normas
[Mh] Termos MeSH secundário: Calibragem
Células Cultivadas
DNA Primase/metabolismo
DNA Polimerase Dirigida por DNA/metabolismo
Escherichia coli/química
Escherichia coli/genética
Escherichia coli/metabolismo
Regulação Bacteriana da Expressão Gênica
Células HEK293
Seres Humanos
Engenharia Metabólica/normas
Enzimas Multifuncionais/metabolismo
Organismos Geneticamente Modificados
Reação em Cadeia da Polimerase/métodos
Estabilidade Proteica
Proteínas Recombinantes/genética
Proteínas Recombinantes/isolamento & purificação
Proteínas Recombinantes/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Multifunctional Enzymes); 0 (Recombinant Proteins); EC 2.7.7.- (DNA Primase); EC 2.7.7.- (PrimPol protein, human); EC 2.7.7.7 (DNA-Directed DNA Polymerase)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171031
[Lr] Data última revisão:
171031
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170914
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0184489


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[PMID]:28731690
[Au] Autor:Deshpande AR; Pochapsky TC; Ringe D
[Ad] Endereço:Departments of Biochemistry and ‡Chemistry and §the Rosenstiel Institute for Basic Biomedical Research, Brandeis University , Waltham, Massachusetts 02454, United States.
[Ti] Título:The Metal Drives the Chemistry: Dual Functions of Acireductone Dioxygenase.
[So] Source:Chem Rev;117(15):10474-10501, 2017 Aug 09.
[Is] ISSN:1520-6890
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Acireductone dioxygenase (ARD) from the methionine salvage pathway (MSP) is a unique enzyme that exhibits dual chemistry determined solely by the identity of the divalent transition-metal ion (Fe or Ni ) in the active site. The Fe -containing isozyme catalyzes the on-pathway reaction using substrates 1,2-dihydroxy-3-keto-5-methylthiopent-1-ene (acireductone) and dioxygen to generate formate and the ketoacid precursor of methionine, 2-keto-4-methylthiobutyrate, whereas the Ni -containing isozyme catalyzes an off-pathway shunt with the same substrates, generating methylthiopropionate, carbon monoxide, and formate. The dual chemistry of ARD was originally discovered in the bacterium Klebsiella oxytoca, but it has recently been shown that mammalian ARD enzymes (mouse and human) are also capable of catalyzing metal-dependent dual chemistry in vitro. This is particularly interesting, since carbon monoxide, one of the products of off-pathway reaction, has been identified as an antiapoptotic molecule in mammals. In addition, several biochemical and genetic studies have indicated an inhibitory role of human ARD in cancer. This comprehensive review describes the biochemical and structural characterization of the ARD family, the proposed experimental and theoretical approaches to establishing mechanisms for the dual chemistry, insights into the mechanism based on comparison with structurally and functionally similar enzymes, and the applications of this research to the field of artificial metalloenzymes and synthetic biology.
[Mh] Termos MeSH primário: Dioxigenases/química
Dioxigenases/metabolismo
Ferro/metabolismo
Enzimas Multifuncionais/química
Enzimas Multifuncionais/metabolismo
Níquel/metabolismo
[Mh] Termos MeSH secundário: Animais
Seres Humanos
Klebsiella oxytoca/enzimologia
Modelos Moleculares
Estrutura Molecular
[Pt] Tipo de publicação:JOURNAL ARTICLE; REVIEW
[Nm] Nome de substância:
0 (Multifunctional Enzymes); 7OV03QG267 (Nickel); E1UOL152H7 (Iron); EC 1.13.11.- (Dioxygenases); EC 1.13.11.- (aci-reductone oxidase (CO-forming))
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170922
[Lr] Data última revisão:
170922
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170722
[St] Status:MEDLINE
[do] DOI:10.1021/acs.chemrev.7b00117


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[PMID]:28558236
[Au] Autor:Moxley MA; Zhang L; Christgen S; Tanner JJ; Becker DF
[Ad] Endereço:Department of Biochemistry, Redox Biology Center, University of Nebraska-Lincoln , Lincoln, Nebraska 68588, United States.
[Ti] Título:Identification of a Conserved Histidine As Being Critical for the Catalytic Mechanism and Functional Switching of the Multifunctional Proline Utilization A Protein.
[So] Source:Biochemistry;56(24):3078-3088, 2017 Jun 20.
[Is] ISSN:1520-4995
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Proline utilization A from Escherichia coli (EcPutA) is a multifunctional flavoenzyme that oxidizes proline to glutamate through proline dehydrogenase (PRODH) and Δ -pyrroline-5-carboxylate dehydrogenase (P5CDH) activities, while also switching roles as a DNA-bound transcriptional repressor and a membrane-bound catabolic enzyme. This phenomenon, termed functional switching, occurs through a redox-mediated mechanism in which flavin reduction triggers a conformational change that increases EcPutA membrane binding affinity. Structural studies have shown that reduction of the FAD cofactor causes the ribityl moiety to undergo a crankshaft motion, indicating that the orientation of the ribityl chain is a key element of PutA functional switching. Here, we test the role of a conserved histidine that bridges from the FAD pyrophosphate to the backbone amide of a conserved leucine residue in the PRODH active site. An EcPutA mutant (H487A) was characterized by steady-state and rapid-reaction kinetics, and cell-based reporter gene experiments. The catalytic activity of H487A is severely diminished (>50-fold) with membrane vesicles as the electron acceptor, and H487A exhibits impaired lipid binding and in vivo transcriptional repressor activity. Rapid-reaction kinetic experiments demonstrate that H487A is 3-fold slower than wild-type EcPutA in a conformational change step following reduction of the FAD cofactor. Furthermore, the reduction potential (E ) of H487A is ∼40 mV more positive than that of wild-type EcPutA, and H487A has an attenuated ability to catalyze the reverse PRODH chemical step of reoxidation by P5C. In this process, significant red semiquinone forms in contrast to the same reaction with wild-type EcPutA, in which facile two-electron reoxidation occurs without the formation of a measurable amount of semiquinone. These results indicate that His487 is critically important for the proline/P5C chemical step, conformational change kinetics, and functional switching in EcPutA.
[Mh] Termos MeSH primário: Proteínas de Bactérias/química
Proteínas de Bactérias/metabolismo
Biocatálise
Sequência Conservada
Histidina/análise
Histidina/metabolismo
Proteínas de Membrana/química
Proteínas de Membrana/metabolismo
Enzimas Multifuncionais/química
Enzimas Multifuncionais/metabolismo
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Proteínas de Bactérias/genética
Escherichia coli/química
Escherichia coli/genética
Escherichia coli/metabolismo
Cinética
Proteínas de Membrana/genética
Modelos Moleculares
Enzimas Multifuncionais/genética
Prolina Oxidase/química
Prolina Oxidase/genética
Prolina Oxidase/metabolismo
Alinhamento de Sequência
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Membrane Proteins); 0 (Multifunctional Enzymes); 0 (PutA protein, Bacteria); 4QD397987E (Histidine); EC 1.5.3.- (Proline Oxidase)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:171101
[Lr] Data última revisão:
171101
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170531
[St] Status:MEDLINE
[do] DOI:10.1021/acs.biochem.7b00046


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[PMID]:28408491
[Au] Autor:Bailey LJ; Doherty AJ
[Ad] Endereço:Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton BN1 9RQ, U.K.
[Ti] Título:Mitochondrial DNA replication: a PrimPol perspective.
[So] Source:Biochem Soc Trans;45(2):513-529, 2017 Apr 15.
[Is] ISSN:1470-8752
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:PrimPol, ase- ymerase), the most recently identified eukaryotic polymerase, has roles in both nuclear and mitochondrial DNA maintenance. PrimPol is capable of acting as a DNA polymerase, with the ability to extend primers and also bypass a variety of oxidative and photolesions. In addition, PrimPol also functions as a primase, catalysing the preferential formation of DNA primers in a zinc finger-dependent manner. Although PrimPol's catalytic activities have been uncovered , we still know little about how and why it is targeted to the mitochondrion and what its key roles are in the maintenance of this multicopy DNA molecule. Unlike nuclear DNA, the mammalian mitochondrial genome is circular and the organelle has many unique proteins essential for its maintenance, presenting a differing environment within which PrimPol must function. Here, we discuss what is currently known about the mechanisms of DNA replication in the mitochondrion, the proteins that carry out these processes and how PrimPol is likely to be involved in assisting this vital cellular process.
[Mh] Termos MeSH primário: DNA Primase/metabolismo
Replicação do DNA
DNA Mitocondrial/genética
DNA Polimerase Dirigida por DNA/metabolismo
Enzimas Multifuncionais/metabolismo
[Mh] Termos MeSH secundário: Animais
Núcleo Celular/genética
DNA Primase/genética
DNA Polimerase Dirigida por DNA/genética
Seres Humanos
Mitocôndrias/genética
Enzimas Multifuncionais/genética
Mutação
[Pt] Tipo de publicação:JOURNAL ARTICLE; REVIEW
[Nm] Nome de substância:
0 (DNA, Mitochondrial); 0 (Multifunctional Enzymes); EC 2.7.7.- (DNA Primase); EC 2.7.7.- (PrimPol protein, human); EC 2.7.7.7 (DNA-Directed DNA Polymerase)
[Em] Mês de entrada:1705
[Cu] Atualização por classe:170502
[Lr] Data última revisão:
170502
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170415
[St] Status:MEDLINE
[do] DOI:10.1042/BST20160162


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[PMID]:27989484
[Au] Autor:Tokarsky EJ; Wallenmeyer PC; Phi KK; Suo Z
[Ad] Endereço:Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA; The Ohio State Biophysics Program, The Ohio State University, Columbus, OH 43210, USA.
[Ti] Título:Significant impact of divalent metal ions on the fidelity, sugar selectivity, and drug incorporation efficiency of human PrimPol.
[So] Source:DNA Repair (Amst);49:51-59, 2017 Jan.
[Is] ISSN:1568-7856
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:Human PrimPol is a recently discovered bifunctional enzyme that displays DNA template-directed primase and polymerase activities. PrimPol has been implicated in nuclear and mitochondrial DNA replication fork progression and restart as well as DNA lesion bypass. Published evidence suggests that PrimPol is a Mn -dependent enzyme as it shows significantly improved primase and polymerase activities when binding Mn , rather than Mg , as a divalent metal ion cofactor. Consistently, our fluorescence anisotropy assays determined that PrimPol binds to a primer/template DNA substrate with affinities of 29 and 979nM in the presence of Mn and Mg , respectively. Our pre-steady-state kinetic analysis revealed that PrimPol incorporates correct dNTPs with 100-fold higher efficiency with Mn than with Mg . Notably, the substitution fidelity of PrimPol in the presence of Mn was determined to be in the range of 3.4×10 to 3.8×10 , indicating that PrimPol is an error-prone polymerase. Furthermore, we kinetically determined the sugar selectivity of PrimPol to be 57-1800 with Mn and 150-4500 with Mg , and found that PrimPol was able to incorporate the triphosphates of two anticancer drugs (cytarabine and gemcitabine), but not two antiviral drugs (emtricitabine and lamivudine).
[Mh] Termos MeSH primário: Coenzimas/metabolismo
DNA Primase/metabolismo
Replicação do DNA
DNA Polimerase Dirigida por DNA/metabolismo
DNA/metabolismo
Magnésio/metabolismo
Manganês/metabolismo
Enzimas Multifuncionais/metabolismo
[Mh] Termos MeSH secundário: Antineoplásicos/metabolismo
Antineoplásicos/uso terapêutico
Antivirais/metabolismo
Antivirais/uso terapêutico
Arabinofuranosilcitosina Trifosfato/metabolismo
Arabinofuranosilcitosina Trifosfato/uso terapêutico
Cátions Bivalentes/metabolismo
Citidina Trifosfato/análogos & derivados
Citidina Trifosfato/metabolismo
Citidina Trifosfato/uso terapêutico
Desoxirribonucleotídeos/metabolismo
Didesoxinucleotídeos/metabolismo
Didesoxinucleotídeos/uso terapêutico
Emtricitabina/análogos & derivados
Emtricitabina/metabolismo
Emtricitabina/uso terapêutico
Seres Humanos
Cinética
Lamivudina/análogos & derivados
Lamivudina/metabolismo
Lamivudina/uso terapêutico
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Antineoplastic Agents); 0 (Antiviral Agents); 0 (Cations, Divalent); 0 (Coenzymes); 0 (Deoxyribonucleotides); 0 (Dideoxynucleotides); 0 (Multifunctional Enzymes); 0 (gemcitabine triphosphate); 0 (lamivudine triphosphate); 13191-15-6 (Arabinofuranosylcytosine Triphosphate); 2T8Q726O95 (Lamivudine); 42Z2K6ZL8P (Manganese); 65-47-4 (Cytidine Triphosphate); 9007-49-2 (DNA); EC 2.7.7.- (DNA Primase); EC 2.7.7.- (PrimPol protein, human); EC 2.7.7.7 (DNA-Directed DNA Polymerase); G70B4ETF4S (Emtricitabine); I38ZP9992A (Magnesium)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:171116
[Lr] Data última revisão:
171116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161220
[St] Status:MEDLINE


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[PMID]:27597531
[Au] Autor:Lévesque N; Christensen KE; Van Der Kraak L; Best AF; Deng L; Caldwell D; MacFarlane AJ; Beauchemin N; Rozen R
[Ad] Endereço:Departments of Human Genetics and Pediatrics, The Research Institute of the McGill University Health Centre, McGill University, Montreal, Quebec, Canada.
[Ti] Título:Murine MTHFD1-synthetase deficiency, a model for the human MTHFD1 R653Q polymorphism, decreases growth of colorectal tumors.
[So] Source:Mol Carcinog;56(3):1030-1040, 2017 Mar.
[Is] ISSN:1098-2744
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The common R653Q variant (∼20% homozygosity in Caucasians) in the synthetase domain of the folate-metabolizing enzyme MTHFD1 reduces purine synthesis. Although this variant does not appear to affect risk for colorectal cancer, we questioned whether it would affect growth of colorectal tumors. We induced tumor formation in a mouse model for MTHFD1-synthetase deficiency (Mthfd1S ) using combined administration of azoxymethane (AOM) and dextran sodium sulfate (DSS) in male and female wild-type and Mthfd1S mice. Tumor size was significantly smaller in MthfdS mice, particularly in males. A reduction in the proliferation of MthfdS mouse embryonic fibroblast cell lines, compared with wild-type lines, was also observed. Tumor number was not influenced by genotype. The amount of inflammation observed within tumors from male Mthfd1S mice was lower than that in wild-type mice. Gene expression analysis in tumor adjacent normal (pre-neoplastic) tissue identified several genes involved in proliferation (Fosb, Fos, Ptk6, Esr2, Atf3) and inflammation (Atf3, Saa1, TNF-α) that were downregulated in MthfdS males. In females, MthfdS genotype was not associated with these gene expression changes, or with differences in tumor inflammation. These findings suggest that the mechanisms directing tumor growth differ significantly between males and females. We suggest that restriction of purine synthesis, reduced expression of genes involved in proliferation, and/or reduced inflammation lead to slower tumor growth in MTHFD1-synthetase deficiency. These findings may have implications for CRC tumor growth and prognosis in individuals with the R653Q variant. © 2016 Wiley Periodicals, Inc.
[Mh] Termos MeSH primário: Aminoidrolases/deficiência
Neoplasias Colorretais/patologia
Formiato-Tetra-Hidrofolato Ligase/deficiência
Meteniltetra-Hidrofolato Cicloidrolase/deficiência
Metilenotetra-Hidrofolato Desidrogenase (NADP)/deficiência
Metilenotetra-Hidrofolato Desidrogenase (NADP)/genética
Antígenos de Histocompatibilidade Menor/genética
Complexos Multienzimáticos/deficiência
Enzimas Multifuncionais/deficiência
Polimorfismo de Nucleotídeo Único
[Mh] Termos MeSH secundário: Animais
Azoximetano/efeitos adversos
Proliferação Celular
Células Cultivadas
Neoplasias Colorretais/induzido quimicamente
Neoplasias Colorretais/genética
Sulfato de Dextrana/efeitos adversos
Feminino
Regulação Neoplásica da Expressão Gênica
Seres Humanos
Masculino
Camundongos
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Minor Histocompatibility Antigens); 0 (Mthfd1 protein, mouse); 0 (Multienzyme Complexes); 0 (Multifunctional Enzymes); 73699-18-0 (formyl-methenyl-methylenetetrahydrofolate synthetase); 9042-14-2 (Dextran Sulfate); EC 1.5.1.5 (MTHFD1 protein, human); EC 1.5.1.5 (Methylenetetrahydrofolate Dehydrogenase (NADP)); EC 3.5.4.- (Aminohydrolases); EC 3.5.4.9 (Methenyltetrahydrofolate Cyclohydrolase); EC 6.3.4.3 (Formate-Tetrahydrofolate Ligase); MO0N1J0SEN (Azoxymethane)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170906
[Lr] Data última revisão:
170906
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160907
[St] Status:MEDLINE
[do] DOI:10.1002/mc.22568


  9 / 77 MEDLINE  
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[PMID]:27466281
[Au] Autor:Gancedo C; Flores CL; Gancedo JM
[Ad] Endereço:Instituto de Investigaciones Biomédicas Alberto Sols, CSIC-UAM, Madrid, Spain cgancedo@iib.uam.es.
[Ti] Título:The Expanding Landscape of Moonlighting Proteins in Yeasts.
[So] Source:Microbiol Mol Biol Rev;80(3):765-77, 2016 Sep.
[Is] ISSN:1098-5557
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Moonlighting proteins are multifunctional proteins that participate in unrelated biological processes and that are not the result of gene fusion. A certain number of these proteins have been characterized in yeasts, and the easy genetic manipulation of these microorganisms has been useful for a thorough analysis of some cases of moonlighting. As the awareness of the moonlighting phenomenon has increased, a growing number of these proteins are being uncovered. In this review, we present a crop of newly identified moonlighting proteins from yeasts and discuss the experimental evidence that qualifies them to be classified as such. The variety of moonlighting functions encompassed by the proteins considered extends from control of transcription to DNA repair or binding to plasminogen. We also discuss several questions pertaining to the moonlighting condition in general. The cases presented show that yeasts are important organisms to be used as tools to understand different aspects of moonlighting proteins.
[Mh] Termos MeSH primário: Candida albicans/enzimologia
Proteínas Fúngicas/metabolismo
Kluyveromyces/enzimologia
Enzimas Multifuncionais/metabolismo
Saccharomyces cerevisiae/enzimologia
Schizosaccharomyces/enzimologia
[Mh] Termos MeSH secundário: Candida albicans/genética
Candida albicans/metabolismo
Reparo do DNA/genética
Proteínas Fúngicas/genética
Kluyveromyces/genética
Kluyveromyces/metabolismo
Enzimas Multifuncionais/genética
Saccharomyces cerevisiae/genética
Saccharomyces cerevisiae/metabolismo
Schizosaccharomyces/genética
Schizosaccharomyces/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; REVIEW
[Nm] Nome de substância:
0 (Fungal Proteins); 0 (Multifunctional Enzymes)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171003
[Lr] Data última revisão:
171003
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160729
[St] Status:MEDLINE
[do] DOI:10.1128/MMBR.00012-16


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[PMID]:27113936
[Au] Autor:Zou HL; Xiao X
[Ad] Endereço:Department of Mechanical and Electronic Information Engineering, Jiangxi University of Applied Science, Nanchang, 330100, China. hongliangzou@126.com.
[Ti] Título:Classifying Multifunctional Enzymes by Incorporating Three Different Models into Chou's General Pseudo Amino Acid Composition.
[So] Source:J Membr Biol;249(4):551-7, 2016 08.
[Is] ISSN:1432-1424
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:With the avalanche of the newly found protein sequences in the post-genomic epoch, there is an increasing trend for annotating a number of newly discovered enzyme sequences. Among the various proteins, enzyme was considered as the one of the largest kind of proteins. It takes part in most of the biochemical reactions and plays a key role in metabolic pathways. Multifunctional enzyme is enzyme that plays multiple physiological roles. Given a multifunctional enzyme sequence, how can we identify its class? Especially, how can we deal with the multi-classes problem since an enzyme may simultaneously belong to two or more functional classes? To address these problems, which are obviously very important both to basic research and drug development, a multi-label classifier was developed via three different prediction models with multi-label K-nearest algorithm. Experimental results obtained on a stringent benchmark dataset of enzymes by jackknife cross-validation test show that the predicting results were exciting, indicating that the current method could be an effective and promising high throughput method in the enzyme research. We hope it could play an important complementary role to the existing predictors in identifying the classes of enzymes.
[Mh] Termos MeSH primário: Aminoácidos/química
Biologia Computacional/métodos
Enzimas Multifuncionais/química
[Mh] Termos MeSH secundário: Algoritmos
Sequência de Aminoácidos
Bases de Dados de Proteínas
Enzimas Multifuncionais/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Amino Acids); 0 (Multifunctional Enzymes)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:171109
[Lr] Data última revisão:
171109
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160427
[St] Status:MEDLINE
[do] DOI:10.1007/s00232-016-9904-3



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