Evidence for a developmentally regulated prespore-specific glutamine synthetase in the cellular slime mould Dictyoselium discoideum
Article Abstract:
The cellular slime mold Dictyoselium discoideum varies the amount of glutamine synthetase it produces as it goes through different stages of its life cycle. Slime mold glutamate synthetase, which enables the cell to metabolize ammonia for the synthesis of amino acids, occurs increasingly when the mold differentiates from vegetative cells, with more of the enzyme concentrated in the prespore cells. The enzyme was characterized as having an optimum pH between 7.8 and 8.2, a temperature optimum of 45 degrees Celsius and kinetic activity rates of 5.9 millimoles for glutamine.
Publication Name: Microbiology
Subject: Biological sciences
ISSN: 1350-0872
Year: 1995
User Contributions:
Comment about this article or add new information about this topic:
Ammonium phosphate in sori of Dictyostelium discoideum promotes spore dormancy through stimulation of the osmosensor ACG
Article Abstract:
A model in which glutamine synthetase (GS) in prespore cells of Dictyostelium discoideum act as a sink for ammonia is presented. The absence of ammonia permits the activation of protein kinase A by the osmotically sensitive adenylyl cyclase aggregation protein (ACA), a reaction that induces spore formation. A decrease in GS and ACA activities after spore formation is balanced by the appearance of the dormancy-inducing adenylyl cyclase osmosensor for germination that is stimulated by the presence of ammonia.
Publication Name: Microbiology
Subject: Biological sciences
ISSN: 1350-0872
Year: 1999
User Contributions:
Comment about this article or add new information about this topic:
Alanyl-tRNA synthetase gene of the extreme acidophilic chemolithototrophic Thiobacillus ferrooxidans is highly homologous to alaS genes from all living kingdoms but cannot be transcribed from its promoter in Escherichia coli
Article Abstract:
The Thiobacillus ferrooxidans alaS gene was cloned, sequenced and compared to other alanyl-tRNA synthetase genes. Its expression in Escherichia coli and T. ferrooxidans was also analyzed. E. coli and T. ferrooxidans were found having the same genomic organization of recA-recX-alaS. However, it was observed that the recA and alaS genes cannot be transcribed from their own promoters in E.coli.
Publication Name: Microbiology
Subject: Biological sciences
ISSN: 1350-0872
Year: 1997
User Contributions:
Comment about this article or add new information about this topic:
- Abstracts: Both insulin and calcium channel signaling are required for developmental regulation of serotonin synthesis in the chemosensory ADF neurons of Caenorhabditis elegans
- Abstracts: Both insulin and calcium channel signaling are required for developmental regulation of serotonin synthesis in the chemosensory ADF neurons of Caenorhabditis elegans. part 2
- Abstracts: Multiple elements and auto-repression regulate Rox1, a repressor of hypoxic genes in Saccharomyces cerevisiae
- Abstracts: ADAM, a widely distributed and developmentally regulated gene family encoding membrane proteins with A Disintegrin And Metalloprotease domain
- Abstracts: Interspecific competition for nest holes causes adult mortality in the collared flycatcher. Ecology and breeding biology of the Hawaii elepaio (Chasiempis sandwichensis bryani)