Glutamine synthetase deficiency

The next most commonly used cell lines are the murine myeloma cell lines such as NS(T and Sp2/0. The NSO cell line is deficient for the glutamine synthetase gene, and the presence of glutamine synthetase (GS) gene on vectors has been used for the selection of stably integrated expression cassettes. ... 

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... 

Glufosinate (GA) is a post-emergence and nonselective herbicide [91, 92], The L-enantiomer of this herbicide, which is also called phos-phinothricin, is a natural microbial phytotoxin, produced by Strepto-myces viridochromogenes and Streptomyces hygroscopicus, and acts as an inhibitor of glutamine synthetase, while the D-enantiomer shows no activity on this enzyme. The herbicidal action involves a rapid accumulation of ammonia, a deficiency in several amino acids, an inhibition of photosynthesis and, finally, the death of the plant cell [91, 93]. 

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