7 research outputs found

    Wide-range transcriptional modulating effect of ntrR under microaerobiosis in Sinorhizobium meliloti

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    Puskas LG, Nagy ZB, Kelemen JZ, et al. Wide-range transcriptional modulating effect of ntrR under microaerobiosis in Sinorhizobium meliloti. MOLECULAR GENETICS AND GENOMICS. 2004;272(3):275-289.A mutation in the second gene in the ntrPR operon results in increased expression of nodulation (nod) and nitrogen fixation (nif) genes in Sinorhizobium meliloti. Since this pleiotropic effect is particularly pronounced in the presence of external combined nitrogen, a nitrogen regulatory function has been suggested for NtrR. To identify the complete set of protein-coding genes influenced by loss of ntrR function, microarray hybridizations were carried out to compare transcript levels in the wild type and mutant strains grown under aerobic and microaerobic conditions. Of the 6207 genes examined, representing the entire genome of S. meliloti, 7% exhibited altered expression: 4.5% of the genes are affected under oxic, 2.5% under microoxic conditions. 0.4% of all the genes are affected under both oxygen concentrations. A microoxic environment is required for the induction of genes related to symbiotic functions but results in the down-regulation of other (e.g. metabolic) functions. When the alterations in transcription levels at low oxygen concentration in the mutant strain were compared to those of the wild type, a modulating effect of the ntrR mutation was observed. For example, symbiotic nif/fix genes were induced in both strains, but the level of induction was higher in the ntrR mutant. In contrast, genes related to transcription/translation functions were down-regulated in both strains, and the effect was greater in the wild-type strain than in the ntrR mutant. A relatively wide range of functions was affected by this modulating influence, suggesting that ntrR is not a nitrogen regulatory gene. Since genes encoding various unrelated functions were affected, we propose that NtrR may either interfere with general regulatory mechanisms, such as phosphorylation/dephosphorylation, or may influence RNA stability

    The phenotypic and genetic signatures of common musculoskeletal pain conditions

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    Musculoskeletal pain conditions, such as fibromyalgia and low back pain, tend to coexist in affected individuals and are characterized by a report of pain greater than expected based on the results of a standard physical evaluation. The pathophysiology of these conditions is largely unknown, we lack biological markers for accurate diagnosis, and conventional therapeutics have limited effectiveness. Growing evidence suggests that chronic pain conditions are associated with both physical and psychological triggers, which initiate pain amplification and psychological distress; thus, susceptibility is dictated by complex interactions between genetic and environmental factors. Herein, we review phenotypic and genetic markers of common musculoskeletal pain conditions, selected based on their association with musculoskeletal pain in previous research. The phenotypic markers of greatest interest include measures of pain amplification and ‘psychological’ measures (such as emotional distress, somatic awareness, psychosocial stress and catastrophizing). Genetic polymorphisms reproducibly linked with musculoskeletal pain are found in genes contributing to serotonergic and adrenergic pathways. Elucidation of the biological mechanisms by which these markers contribute to the perception of pain in these patients will enable the development of novel effective drugs and methodologies that permit better diagnoses and approaches to personalized medicine

    Can stress response genes be used to improve the symbiotic performance of rhizobia?

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