Glutamine synthetase activation

Oliver, C.N., Starke-Reed, P.E., Stadtman, E.R., Liu, G.J., Carney, J.M. and Floyd, R.A. (1990). Oxidative damage to brain proteins, loss of glutamine synthetase activity, and production of free radicals during ischemia/reperfusion-induced injury to gerbil brain. Proc. Natl Acad. Sd. USA 87, 5144-5147. 

Max SR, Silbergeld EK. 1987. Skeletal muscle glucocorticoid receptor and glutamine synthetase activity in the wasting syndrome in rats-treated with 2,3,7,8-tetrachlorodibenzo-p-dioxin. Toxicol Appl Pharmacol 15 523-527. 

Glutamine synthetase activity was determined by following glutamine formation. The reaction contained 50 mM Hepes-NaOH (50 mM). The reaction was started by addition of ATP and stopped after 15 minutes of incubation at 30°C by addition of 0.6 mL of 1 N HC1. 

Bressler, S. L., and Ahmed, S. I. (1984). Detection of glutamine synthetase activity in marine phytoplankton Optimization of the biosynthetic assay. Mar. Ecol. Prog. Ser. 14, 207—217. 

El Alaoui, S., Diez, J., Humanes, L., Toribio, F., Partensky, F., and Garcia-Fernandez, J. M. (2001). In vivo regulation of glutamine synthetase activity in the marine chlorophyU b-containing cyanobacterium Prochlorococcus sp strain PCC 9511 (oxyphotobacteria). Appl. Environ. Microbiol. 67, 2202-2207. 

Rees, T. A. V., Larson, T. R., Heldens, J. W. G., and Huning, E. G. J. (1995). In situ glutamine synthetase activity in a marine unicellular alga (Development of a sensitive colorimetric assay and the effects of nitrogen status on enzyme activity). Plant Physiol. 109, 1405—1410. 

Slawyk, G., and Rodier, M. (1986). Glutamine synthetase activity in Chaetoceros affmis (BaciUariophy-ceae)—Comparison with other estimates of nitrogen utilization during nutrient perturbation. J. Phycol. 22, 270-275. 

Pregnall, A. M., Smith, R. D., and Alberte, R. S. (1987). Glutamine synthetase activity and free amino acid pools of eelgrass (Zostera marina L.) roots. J. Exp. Mar. Biol. Ecol. 106, 211—228. 

Maurin-Defossez, C., and LeGal, Y. (1998). Diel periodicity of glutamine synthetase activity during the cell cycle oiEmiliania huxleyi. Plant Physiol. Biochem. 36, 233-236. 

Figure 9-1 The highlights of the chick embryonic neural retina micromass cultures are depicted. The tissue is harvested and digested to a single-cell suspension. These are placed into culture, and after 24 h three parameters are measured (a) the number of aggregates that are produced, (b) the size of the aggregates, and (c) their protein content. After five days cortisol is added to precociously induce glutamine synthetase activity. This is measured two days later, after a total of seven days of culture. Each parameter is uniquely sensitive to different agents, but a decrease in any one parameter is considered to be toxicologically relevant.

CENR - None - Cell aggregate count - Aggregate size - Aggregate protein content - Glutamine synthetase activity - Perturbation of any endpoint... 

Stanimirovic DB, Ball R, Small DL, Muruganandam A (1999) Developmental regulation of glutamate transporters and glutamine synthetase activity in astrocyte cultures differentiated in vitro. Int J Dev Neurosci 77 173-184. 

ACTIVE FIGURE 23.4 The allosteric regulation of glutamine synthetase activity by feedback inhibition. Sign in at www.thomsonedu.com/login to explore an interactive version of this figure. 

Presumably two potential routes of ammonia incorporation exist (58, 59). The high affinity route consists of glutamine synthetase activity working in conjunction with glutamate... 

One of the primary effects of Mn(II) deficiency is the increased susceptibility to convulsions or seizures which occurs in both ataxic and non-ataxic animals [369]. More recently, there has been increasing evidence that blood levels of Mn(II) are lower in epileptic than in normal patients [370-375]. One hypothesis for the biochemical basis of this effect in the CNS is that lower Mn(II) concentrations in the glial cytoplasm lowers glutamine synthetase activity, which leads to higher extracellular levels of the excitory L-glutamate. This results in a lower firing threshold for neurons with Glu-activated receptors [177]. Other effects of Mn(II) on the nervous system include changes.in the behaviour of cardio-pulmonary nerves [376], effects... 

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