RESUMO
Hanseniaspora guilliermondii is a well-recognized producer of acetate esters associated with fruity and floral aromas. The molecular mechanisms underneath this production or the environmental factors modulating it remain unknown. Herein, we found that, unlike Saccharomyces cerevisiae, H. guilliermondii over-produces acetate esters and higher alcohols at low carbon-to-assimilable nitrogen (C:N) ratios, with the highest titers being obtained in the amino acid-enriched medium YPD. The evidences gathered support a model in which the strict preference of H. guilliermondii for amino acids as nitrogen sources results in a channeling of keto-acids obtained after transamination to higher alcohols and acetate esters. This higher production was accompanied by higher expression of the four HgAATs, genes, recently proposed to encode alcohol acetyl transferases. In silico analyses of these HgAat's reveal that they harbor conserved AATs motifs, albeit radical substitutions were identified that might result in different kinetic properties. Close homologues of HgAat2, HgAat3, and HgAat4 were only found in members of Hanseniaspora genus and phylogenetic reconstruction shows that these constitute a distinct family of Aat's. These results advance the exploration of H. guilliermondii as a bio-flavoring agent providing important insights to guide future strategies for strain engineering and media manipulation that can enhance production of aromatic volatiles.
Assuntos
Hanseniaspora , Vinho , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Hanseniaspora/genética , Vinho/análise , Ésteres/análise , Filogenia , Fermentação , Álcoois/metabolismo , Acetatos/metabolismo , Nitrogênio/metabolismo , Acetiltransferases/genética , Acetiltransferases/metabolismoRESUMO
Thalidomide is widely used for several diseases; however, it causes malformations in embryos exposed during pregnancy. The complete understanding of the mechanisms by which thalidomide affects the embryo development has not yet been obtained. The phenotypic similarity makes TE a phenocopy of syndromes caused by mutations in ESCO2, SALL4 and TBX5 genes. Recently, SALL4 and TBX5 were demonstrated to be thalidomide targets. To understand if these genes act in the TE development, we sequenced them in 27 individuals with TE; we verified how thalidomide affect them in human pluripotent stem cells (hPSCs) through a differential gene expression (DGE) analysis from GSE63935; and we evaluated how these genes are functionally related through an interaction network analysis. We identified 8 variants in ESCO2, 15 in SALL4 and 15 in TBX5. We compared allelic frequencies with data from ExAC, 1000 Genomes and ABraOM databases; eight variants were significantly different (p < 0.05). Eleven variants in SALL4 and TBX5 were previously associated with cardiac diseases or malformations; however, in TE sample there was no association. Variant effect prediction tools showed 97% of the variants with potential to influence in these genes regulation. DGE analysis showed a significant reduction of ESCO2 in hPSCs after thalidomide exposure.
Assuntos
Acetiltransferases/genética , Proteínas Cromossômicas não Histona/genética , Predisposição Genética para Doença , Proteínas com Domínio T/genética , Teratogênese/genética , Talidomida/efeitos adversos , Fatores de Transcrição/genética , Anormalidades Múltiplas/induzido quimicamente , Anormalidades Múltiplas/genética , Brasil , Linhagem Celular , Anormalidades Craniofaciais/induzido quimicamente , Anormalidades Craniofaciais/genética , Conjuntos de Dados como Assunto , Síndrome da Retração Ocular/induzido quimicamente , Síndrome da Retração Ocular/genética , Ectromelia/induzido quimicamente , Ectromelia/genética , Feminino , Perfilação da Expressão Gênica , Frequência do Gene , Cardiopatias Congênitas/induzido quimicamente , Cardiopatias Congênitas/genética , Comunicação Interatrial/induzido quimicamente , Comunicação Interatrial/genética , Humanos , Hipertelorismo/induzido quimicamente , Hipertelorismo/genética , Hanseníase/tratamento farmacológico , Deformidades Congênitas das Extremidades Inferiores/induzido quimicamente , Deformidades Congênitas das Extremidades Inferiores/genética , Masculino , Mutação , Células-Tronco Pluripotentes , Polimorfismo de Nucleotídeo Único , Gravidez , Complicações na Gravidez/tratamento farmacológico , Mapas de Interação de Proteínas/genética , Teratogênese/efeitos dos fármacos , Deformidades Congênitas das Extremidades Superiores/induzido quimicamente , Deformidades Congênitas das Extremidades Superiores/genéticaRESUMO
The genus Mycobacterium comprises clinically important pathogens such as M. tuberculosis, which has reemerged as a major cause of morbidity and mortality world-wide especially with the emergence of multidrug-resistant strains. The use of fast-growing species such as Mycobacterium smegmatis has allowed important advances to be made in the field of mycobacterial genetics and in the study of the mechanisms of resistance in mycobacteria. The isolation of an aminoglycoside-resistance gene from Mycobacterium fortuitum has recently been described. The aac(2')-Ib gene is chromosomally encoded and is present in all isolates of M. fortuitum. The presence of this gene in other mycobacterial species is studied here and genes homologous to that of M. fortuitum have been found in all mycobacterial species studied. In this report, the cloning of the aac(2')-Ic gene from M. tuberculosis H37Rv and the aac(2')-Id gene from M. smegmatis mc(2)155 is described. Southern blot hybridizations have shown that both genes are present in all strains of this species studied to date. In addition, the putative aac(2')-Ie gene has been located in a recent release of the Mycobacterium leprae genome. The expression of the aac(2')-Ic and aac(2')-Id genes has been studied in M. smegmatis and only aac(2')-Id is correlated with aminoglycoside resistance. In order to elucidate the role of the aminoglycoside 2'-N-acetyltransferase genes in mycobacteria and to determine whether they are silent resistance genes or whether they have a secondary role in mycobacterial metabolism, the aac(2')-Id gene from M. smegmatis has been disrupted in the chromosome of M. smegmatis mc(2)155. The disruptant shows an increase in aminoglycoside susceptibility along with a slight increase in the susceptibility to lysozyme.
Assuntos
Acetiltransferases/genética , Mycobacterium tuberculosis/genética , Mycobacterium/genética , Sequência de Aminoácidos , Aminoglicosídeos/metabolismo , Aminoglicosídeos/farmacologia , Mapeamento Cromossômico , Clonagem Molecular , Resistência Microbiana a Medicamentos/genética , Regulação Bacteriana da Expressão Gênica , Regulação Enzimológica da Expressão Gênica , Dados de Sequência Molecular , Muramidase/farmacologia , Mutagênese Insercional , Mycobacterium/efeitos dos fármacos , Mycobacterium leprae/genética , Plasmídeos , Recombinação Genética , Homologia de Sequência de AminoácidosRESUMO
The sulfones are the drug of choice in the treatment of leprosy, with dapsone as the clear favorite. The major route for dapsone metabolism leading to its inactivation and excretion is via acetylation by hepatic N-acetyl transferase (NAT), as is the case with isoniazid (INH) and sulfamethazine (SMZ). The enzyme is known to exhibit genetic polymorphism. The object of the present study is mainly to determine the incidence of acetylator phenotype in a population of leprosy patients with a view to evaluating the degree of association, if any, between phenotype and the disease. Obviously a knowledge of the incidence of the phenotypes may provide a valuable contribution to the institution of more rational and successful therapy. In the normal or control subjects, as well as in the leprosy patients, the frequency distribution histograms of the percentage acetylsulfamethazine in urine and serum samples are bimodal, and this indicates the existence of a genetic polymorphism. Based on the bimodality, individuals were classified as either "rapid" or "slow" acetylators, and the incidence of the slow acetylator phenotype of about 51% was observed in the leprosy population. This gives a relatively high incidence of the allele controlling the slow acetylator (q = 0.73). Although there is evidence that the mean percentage of SMZ acetylated in leprosy patients of the slow acetylator phenotype is significantly higher than that observed for the same phenotype in the controls (t = 4.86, P less than 0.02), statistical analyses show that there is no association between the slow acetylator phenotype and the disease.(ABSTRACT TRUNCATED AT 250 WORDS)