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J. Esclapez - One of the best experts on this subject based on the ideXlab platform.

  • New proposal of Nitrogen Metabolism regulation by small RNAs in the extreme halophilic archaeon Haloferax mediterranei
    Molecular Genetics and Genomics, 2020
    Co-Authors: Gloria Paya, María José Bonete, Monica Camacho, Vanesa Bautista, J. Esclapez
    Abstract:

    The regulatory networks involved in the uptake and Metabolism of different Nitrogen sources in response to their availability are crucial in all organisms. Nitrogen Metabolism pathways have been studied in detail in archaea such as the extreme halophilic archaeon Haloferax mediterranei. However, knowledge about Nitrogen Metabolism regulation in haloarchaea is very scarce, and no transcriptional regulators involved in Nitrogen Metabolism have been identified to date. Advances in the molecular biology field have revealed that many small RNAs (sRNAs) are involved in the regulation of a diverse metabolic pathways. Surprisingly, no studies on regulation mediated by sRNAs have focused on the response to environmental fluctuations in Nitrogen in haloarchaea. To identify sRNAs involved in the transcriptional regulation of Nitrogen assimilation genes in Haloferax mediterranei and, thus, propose a novel regulatory mechanism, RNA-Seq was performed using cells grown in the presence of two different Nitrogen sources. The differential transcriptional expression analysis of the RNA-Seq data revealed differences in the transcription patterns of 102 sRNAs according to the Nitrogen source, and the molecular functions, cellular locations and biological processes with which the target genes were associated were predicted. These results enabled the identification of four sRNAs that could be directly related to the regulation of genes involved in Nitrogen Metabolism. This work provides the first proposed regulatory mechanism of Nitrogen assimilation-related gene expression by sRNAs in haloarchaea as an alternative to transcriptional regulation mediated by proteins.

Afaf Elansary - One of the best experts on this subject based on the ideXlab platform.

  • mechanism of Nitrogen Metabolism related parameters and enzyme activities in the pathophysiology of autism
    Journal of Neurodevelopmental Disorders, 2012
    Co-Authors: Ghada Abu Shmais, Laila Y Alayadhi, Abeer Aldbass, Afaf Elansary
    Abstract:

    Background There is evidence that impaired Metabolism play an important role in the etiology of many neuropsychiatric disorders. Although this has not been investigated to date, several recent studies proposed that Nitrogen Metabolism-related parameters may have a pathophysiological role in autism.

  • mechanism of Nitrogen Metabolism related parameters and enzyme activities in the pathophysiology of autism
    Journal of Neurodevelopmental Disorders, 2012
    Co-Authors: Ghada Abu Shmais, Laila Y Alayadhi, Abeer Aldbass, Afaf Elansary
    Abstract:

    There is evidence that impaired Metabolism play an important role in the etiology of many neuropsychiatric disorders. Although this has not been investigated to date, several recent studies proposed that Nitrogen Metabolism-related parameters may have a pathophysiological role in autism. The study enrolled 20 Saudi boys with autism aged 4 to 12 years and 20 healthy controls matched for age and gender. Levels of creatine, urea, ammonia, gamma-aminobutyric acid (GABA), glutamate:glutamine (Glu:Gln) ratio, and enzymatic activities of glutamate dehydrogenase, 5'-nucleotidase, and adenosine deaminase (ADA) were determined in plasma samples from both groups. We found a significant elevation of creatine, 5'-nucleotidase, GABA, and glutamic acid and a significant decrease in the enzymatic activity of ADA and glutamine level in patients with autism compared with healthy controls. The most significant variation between the two groups was found in the Glu:Gln ratio. A raised Glu:Gln ratio together with positive correlations in creatine, GABA, and 5'-nucleotidase levels could contribute to the pathophysiology of autism, and might be useful diagnostic markers. The mechanism through which these parameters might be related to autism is discussed in detail.

Gloria Paya - One of the best experts on this subject based on the ideXlab platform.

  • New proposal of Nitrogen Metabolism regulation by small RNAs in the extreme halophilic archaeon Haloferax mediterranei
    Molecular Genetics and Genomics, 2020
    Co-Authors: Gloria Paya, María José Bonete, Monica Camacho, Vanesa Bautista, J. Esclapez
    Abstract:

    The regulatory networks involved in the uptake and Metabolism of different Nitrogen sources in response to their availability are crucial in all organisms. Nitrogen Metabolism pathways have been studied in detail in archaea such as the extreme halophilic archaeon Haloferax mediterranei. However, knowledge about Nitrogen Metabolism regulation in haloarchaea is very scarce, and no transcriptional regulators involved in Nitrogen Metabolism have been identified to date. Advances in the molecular biology field have revealed that many small RNAs (sRNAs) are involved in the regulation of a diverse metabolic pathways. Surprisingly, no studies on regulation mediated by sRNAs have focused on the response to environmental fluctuations in Nitrogen in haloarchaea. To identify sRNAs involved in the transcriptional regulation of Nitrogen assimilation genes in Haloferax mediterranei and, thus, propose a novel regulatory mechanism, RNA-Seq was performed using cells grown in the presence of two different Nitrogen sources. The differential transcriptional expression analysis of the RNA-Seq data revealed differences in the transcription patterns of 102 sRNAs according to the Nitrogen source, and the molecular functions, cellular locations and biological processes with which the target genes were associated were predicted. These results enabled the identification of four sRNAs that could be directly related to the regulation of genes involved in Nitrogen Metabolism. This work provides the first proposed regulatory mechanism of Nitrogen assimilation-related gene expression by sRNAs in haloarchaea as an alternative to transcriptional regulation mediated by proteins.

Ghada Abu Shmais - One of the best experts on this subject based on the ideXlab platform.

  • mechanism of Nitrogen Metabolism related parameters and enzyme activities in the pathophysiology of autism
    Journal of Neurodevelopmental Disorders, 2012
    Co-Authors: Ghada Abu Shmais, Laila Y Alayadhi, Abeer Aldbass, Afaf Elansary
    Abstract:

    Background There is evidence that impaired Metabolism play an important role in the etiology of many neuropsychiatric disorders. Although this has not been investigated to date, several recent studies proposed that Nitrogen Metabolism-related parameters may have a pathophysiological role in autism.

  • mechanism of Nitrogen Metabolism related parameters and enzyme activities in the pathophysiology of autism
    Journal of Neurodevelopmental Disorders, 2012
    Co-Authors: Ghada Abu Shmais, Laila Y Alayadhi, Abeer Aldbass, Afaf Elansary
    Abstract:

    There is evidence that impaired Metabolism play an important role in the etiology of many neuropsychiatric disorders. Although this has not been investigated to date, several recent studies proposed that Nitrogen Metabolism-related parameters may have a pathophysiological role in autism. The study enrolled 20 Saudi boys with autism aged 4 to 12 years and 20 healthy controls matched for age and gender. Levels of creatine, urea, ammonia, gamma-aminobutyric acid (GABA), glutamate:glutamine (Glu:Gln) ratio, and enzymatic activities of glutamate dehydrogenase, 5'-nucleotidase, and adenosine deaminase (ADA) were determined in plasma samples from both groups. We found a significant elevation of creatine, 5'-nucleotidase, GABA, and glutamic acid and a significant decrease in the enzymatic activity of ADA and glutamine level in patients with autism compared with healthy controls. The most significant variation between the two groups was found in the Glu:Gln ratio. A raised Glu:Gln ratio together with positive correlations in creatine, GABA, and 5'-nucleotidase levels could contribute to the pathophysiology of autism, and might be useful diagnostic markers. The mechanism through which these parameters might be related to autism is discussed in detail.

Christof Francke - One of the best experts on this subject based on the ideXlab platform.

  • Comparative genome analysis of central Nitrogen Metabolism and its control by GlnR in the class Bacilli
    BMC Genomics, 2012
    Co-Authors: Tom Groot Kormelink, W. M. de Vos, Yanick Hagemeijer, Lex Overmars, Eric Koenders, Rolnald J. Siezen, Christof Francke
    Abstract:

    BackgroundThe assimilation of Nitrogen in bacteria is achieved through only a few metabolic conversions between alpha-ketoglutarate, glutamate and glutamine. The enzymes that catalyze these conversions are glutamine synthetase, glutaminase, glutamate dehydrogenase and glutamine alpha-ketoglutarate aminotransferase. In low-GC Gram-positive bacteria the transcriptional control over the levels of the related enzymes is mediated by four regulators: GlnR, TnrA, GltC and CodY. We have analyzed the genomes of all species belonging to the taxonomic families Bacillaceae, Listeriaceae, Staphylococcaceae, Lactobacillaceae, Leuconostocaceae and Streptococcaceae to determine the diversity in central Nitrogen Metabolism and reconstructed the regulation by GlnR.ResultsAlthough we observed a substantial difference in the extent of central Nitrogen Metabolism in the various species, the basic GlnR regulon was remarkably constant and appeared not affected by the presence or absence of the other three main regulators. We found a conserved regulatory association of GlnR with glutamine synthetase (glnRA operon), and the transport of ammonium (amtB-glnK) and glutamine/glutamate (i.e. via glnQHMP, glnPHQ, gltT, alsT). In addition less-conserved associations were found with, for instance, glutamate dehydrogenase in Streptococcaceae, purine catabolism and the reduction of nitrite in Bacillaceae, and aspartate/asparagine deamination in Lactobacillaceae.ConclusionsOur analyses imply GlnR-mediated regulation in constraining the import of ammonia/amino-containing compounds and the production of intracellular ammonia under conditions of high Nitrogen availability. Such a role fits with the intrinsic need for tight control of ammonia levels to limit futile cycling.