RESUMO
A growing body of evidence shows that there is an intimate connection between proteins required for genome stability and stationary phase survival. In this work we show that the integral membrane protein UspB, a member of the RpoS regulon, is required for proper DNA repair as mutants lacking uspB are hypersensitive to several DNA damaging agents including ultraviolet light, mitomycin C, bleomycin and ciprofloxacin. Genetic and physical studies demonstrate that UspB acts in the RuvABC recombination repair pathway and removing uspB creates a phenocopy of the Holliday junction resolvase mutant, ruvC. Further, we show that the uspB mutant phenotype can be suppressed by ectopic overproduction of RuvC and that both ruvC and uspB mutants can be suppressed by inactivating recD. The fact that RuvABC-dependent repair requires UspB for proper activity suggests that the sigma-S regulon works together with DNA repair pathways under stress conditions to defend the cell against genotoxic stress.
Assuntos
Proteínas de Bactérias/genética , Endodesoxirribonucleases/metabolismo , Escherichia coli K12/genética , Escherichia coli K12/metabolismo , Proteínas de Escherichia coli/metabolismo , Proteínas de Membrana/metabolismo , Regulon , Fator sigma/genética , Proteínas de Bactérias/metabolismo , Reparo do DNA/genética , Reparo do DNA/efeitos da radiação , Endodesoxirribonucleases/biossíntese , Escherichia coli K12/efeitos da radiação , Proteínas de Escherichia coli/biossíntese , Proteínas de Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica/efeitos da radiação , Proteínas de Membrana/genética , Mutação , Fenótipo , Recombinação Genética , Fator sigma/metabolismo , Raios UltravioletaRESUMO
The evolution of reading frame maintenance must have been an early event, and presumably preceded the emergence of the three domains Archaea, Bacteria and Eukarya. Features evolved early in reading frame maintenance may still exist in present-day organisms. We show that one such feature may be the modified nucleoside 1-methylguanosine (m(1)G37), which prevents frameshifting and is present adjacent to and 3' of the anticodon (position 37) in the same subset of tRNAs from all organisms, including that with the smallest sequenced genome (Mycoplasma genitalium), and organelles. We have identified the genes encoding the enzyme tRNA(m(1)G37)methyltransferase from all three domains. We also show that they are orthologues, and suggest that they originated from a primordial gene. Lack of m(1)G37 severely impairs the growth of a bacterium and a eukaryote to a similar degree. Yeast tRNA(m(1)G37)methyltransferase also synthesizes 1-methylinosine and participates in the formation of the Y-base (yW). Our results suggest that m(1)G37 existed in tRNA before the divergence of the three domains, and that a tRNA(m(1)G37)methyltrans ferase is part of the minimal set of gene products required for life.
Assuntos
Archaea/genética , Bactérias/genética , Evolução Biológica , Mycoplasma/genética , RNA Bacteriano/genética , RNA de Transferência/genética , Fases de Leitura , Salmonella typhimurium/genética , tRNA Metiltransferases/genética , tRNA Metiltransferases/metabolismo , Sequência de Aminoácidos , Animais , Genoma Bacteriano , Humanos , Dados de Sequência Molecular , Salmonella typhimurium/crescimento & desenvolvimento , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , tRNA Metiltransferases/químicaAssuntos
Busca de Comunicante , Controle de Infecções , Meningite Meningocócica/prevenção & controle , Infecções Meningocócicas/prevenção & controle , Antibioticoprofilaxia , Humanos , Meningite Meningocócica/transmissão , Infecções Meningocócicas/transmissão , Guias de Prática Clínica como Assunto , Fatores de Risco , SuéciaRESUMO
The article describes the role of ward managers at middle-sized hospitals and analyzes that role with respect to motivation, role content, and skills and competencies, as well as challenges and problems. The most striking result of this study was the unwillingness of Swedish executive nurses to return to nursing. Among the findings that explain this "career with no return" are an increased taste for challenges; an irrevocable, new professional identity; and a loss of nursing skills and the ability to subordinate. The article discusses the implications for recruitment and education.
Assuntos
Atitude do Pessoal de Saúde , Descrição de Cargo , Satisfação no Emprego , Enfermeiros Administradores/organização & administração , Enfermeiros Administradores/psicologia , Competência Profissional , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Motivação , Pesquisa em Administração de Enfermagem , SuéciaRESUMO
Rheumatoid arthritis (RA) is one of our most common disabling diseases today. Whether or not RA also existed in ancient times has been questioned and debated in recent years. Supporters of the view of recent onset claim that evidence of the existence of RA in antiquity can be found neither in old literature nor in paintings--and most important--convincing paleopathological finds are lacking. The following presentation reviews the results of an examination of skeletons found during an excavation of a neolithic burial place in the island of Gotland, Sweden. In two skeletons there were marked peripheral changes in both large and small joints. These changes are compatible with in vivo presence of a chronic aseptic polyarthritis. Different diagnostic possibilities for such polyarticular joint disease are discussed. It is suggested that RA might be the most probable alternative although other possibilities cannot be excluded.
