Regulation of hydrogen utilisation in Rhizobium japonicum by cyclic AMP

Lim, S. T.; Shanmugam, K. T.

doi:10.1016/0304-4165(79)90121-1

Cited by 90 publications

(42 citation statements)

References 22 publications

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“…This implied that carbon substrates repressed or inhibited hydrogenase synthesis or activity. Repression of uptake hydrogenase activity by carbon substrates has also been observed in Alcaligenes eutrophus (Schlegel & Eberhardt, 1972) and Rhizobium japonicum (Maier et al, 1978(Maier et al, , 1979Lim & Shanmugam, 1979). Other factors known to affect hydrogenase activity include 0, and H, (Yates et al, 1980).…”

Section: Introductionmentioning

confidence: 96%

The Relationship Between Hydrogenase and Nitrogenase in Azotobacter chroococcum: Effect of Nitrogen Sources on Hydrogenase Activity

et al. 1980

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313The effects of different nitrogen sources on the H,-uptake hydrogenase activity were studied in batch-grown and carbon-or sulphate-limited chemostat cultures of Azotobacter chroococcum. Hydrogenase activity was significantly higher in N,-fixing than in NH4+-or NO,--dependent cultures under carbon limitation or in early-stationary phase batch growth but was not influenced by the nitrogen source in sulphate-limited cultures. Hydrogenase activity developed nearly two generation times later than nitrogenase activity during the transition from NH,+-to N,-dependent growth in carbon-limited cultures. A possible explanation is that H, produced by nitrogenase induced hydrogenase synthesis. Carbonlimited N,-fixing cultures possessed higher hydrogenase activity than did sulphate-or 0,-limited cultures. It appears that carbon substrates or metabolites act as primary repressors of hydrogenase activity and that secondary effectors, such as nitrogen sources or H,, act when such repression is removed.

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Section: Introductionmentioning

confidence: 96%

The Relationship Between Hydrogenase and Nitrogenase in Azotobacter chroococcum: Effect of Nitrogen Sources on Hydrogenase Activity

et al. 1980

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“…In the same organism, malate and other tricarboxylic acid cycle intermediates repressed hydrogen uptake and glutamate utilization when glutamate is utilized as the sole source of carbon and nitrogen. The addition of exogenous cAMP alleviates this inhibition (30). In B. japonicum, growth and ex planta nitrogenase activity were inhibited when 100 M cGMP was added to the culture media (23,31).…”

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confidence: 99%

The Rhizobium etli cyaC Product: Characterization of a Novel Adenylate Cyclase Class

et al. 2002

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Adenylate cyclases (ACs) catalyze the formation of 3,5-cyclic AMP (cAMP) from ATP. A novel AC-encoding gene, cyaC, was isolated from Rhizobium etli by phenotypic complementation of an Escherichia coli cya mutant. The functionality of the cyaC gene was corroborated by its ability to restore cAMP accumulation in an E. coli cya mutant. Further, overexpression of a malE::cyaC fusion protein allowed the detection of significant AC activity levels in cell extracts of an E. coli cya mutant. CyaC is unrelated to any known AC or to any other protein exhibiting a currently known function. Thus, CyaC represents the first member of a novel class of ACs (class VI). Hypothetical genes of unknown function similar to cyaC have been identified in the genomes of the related bacterial species Mesorhizobium loti, Sinorhizobium meliloti, and Agrobacterium tumefaciens. The cyaC gene is cotranscribed with a gene similar to ohr of Xanthomonas campestris and is expressed only in the presence of organic hydroperoxides. The physiological performance of an R. etli cyaC mutant was indistinguishable from that of the wild-type parent strain both under free-living conditions and during symbiosis.

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“…Bacteria were maintained asymbiotically on agar slopes of LMB medium (19). Three-d-old cultures were suspended in sterile nutrient solution and used to inoculate seedlings at planting.…”

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confidence: 99%

A Transmissible Plant Shoot Factor Promotes Uptake Hydrogenase Activity in Rhizobium Symbionts

Bedmar

Phillips²

1984

Plant Physiol.

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Shoot/root grafting studies showed organ and host cultivar effects on net H2 evolution from Pisum sativum L. root nodules. Net H2 evolution from those nodules represents the sum of H2 formed by Rhizobiam nitrogenase and H2 oxidized by any uptake hydrogenase present in the bacteria. Grafts between pea cultivars 'JI1205' or 'Alaska' and 'Feltham First' in Parallel grafting experiments using the same pea cultivars in symbioses with R. kguminosarum strain 300, which lacks uptake hydrogenase activity, suggested that a transmissible shoot factor(s) altered H2 formation from nitrogenase by changing the electron allocation coefficient of that enzyme complex.The root and shoot factor(s) detected in this study had no permanent effect on strain 128C53. Bacterial cells isolated from Feltham First nodules with low H2 uptake activity formed root nodules on JI1205 and Alaska with high H2 uptake activity. Bacteroids isolated from nodules on intact JI1205, Alaska, or Feltham First plants with high, medium, or low H2 uptake activity, respectively, maintained those phenotypes during in vitro assays.Two enzyme systems metabolizing H2 can be present in root nodules of the Rhizobium-legume symbiosis. Hydrogen is formed by the nitrogenase enzyme complex through an ATPdependent reduction of protons to H2 (6). Hydrogen uptake, associated with oxidation by an uptake hydrogenase system (1 1), was first reported for leguminous root nodules in pea (24), and the observation subsequently was confirmed and extended to other legumes (12 show various patterns of H2 metabolism. Rhizobium leguminosarum strains tested in a single pea cultivar produced different amounts of net H2 evolution and uptake hydrogenase activity (4,22, 25). The assumption that such H2 uptake-positive (Hup+) or H2 uptake-negative (Hup-) phenotypes had a genetic basis was confirmed by the genetic transfer of a Hup+ trait between R. leguminosarum strains (5, 9) and by the production of

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Regulation of hydrogen utilisation in Rhizobium japonicum by cyclic AMP

Cited by 90 publications

References 22 publications

The Relationship Between Hydrogenase and Nitrogenase in Azotobacter chroococcum: Effect of Nitrogen Sources on Hydrogenase Activity

The Relationship Between Hydrogenase and Nitrogenase in Azotobacter chroococcum: Effect of Nitrogen Sources on Hydrogenase Activity

The Rhizobium etli cyaC Product: Characterization of a Novel Adenylate Cyclase Class

A Transmissible Plant Shoot Factor Promotes Uptake Hydrogenase Activity in Rhizobium Symbionts

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