Glutamine Synthetase / Glutaminase
Glutamate / Glutamine

Author: Gianpiero Pescarmona
Date: 16/03/2011



A short protein description with the molecular wheight, isoforms, etc...
Use, when available, the link to Wikipedia (Es Trypsin)

External links not available on Wikipedia have to be added here


Your Favorite Gene Sigma"URL":


When relevant for the function

  • Primary structure
  • Secondary structure
  • Tertiary structure
  • Quaternary structure

Protein Aminoacids Percentage

Enzymes involved

  • Glutamine Synthetase
  • Glutaminase
    • Kidney
    • Liver


mRNA synthesis

[The correlation of consciousness level and the concentration of CSF ammonia in a patient with adult-type citrullinemia]., 1991

A 29-year-old man who had a taste for peanuts frequently showed abnormal behaviors. Physical examination revealed consciousness disturbance associated with flapping tremor, hypotonus in the extremities, and hypoactive deep tendon reflexes. Laboratory examination showed hyperammonemia with mild liver injury. A level of serum citrulline was 14 times higher than the upper limit of normal. A diagnosis of type 2 citrullinemia (Seheki et al) was established by the decreased argininosuccinate synthetase (ASS) in liver with low amount of ASS protein and normal kinetic properties. Diurnal fluctuation of consciousness level in this patient was not correlated with the concentration of ammonia in serum, but with that in cerebrospinal fluid. Main metabolic pathway of ammonia in brain is considered to be localized in astrocytes which have receptors for glucocorticoids. Glucocorticoids induce additional glutamine synthetase activity. Circadian rhythm of cortisol level might play a role in diurnal fluctuation of consciousness level in patients with citrullinemia.

protein synthesis

post-translational modifications


cellular localization,

biological function


  • Enzymes
BRENDA - The Comprehensive Enzyme Information System"URL":
KEGG Pathways"URL":
Human Metabolome Database"URL":
  • Cell signaling and Ligand transport
  • Structural proteins



2012-10-26T07:41:22 - Annamaria Vernone

Glutamate and Glutamine in the Brain - Department of Pediatrics, University of Pennsylvania School of Medicine [J. Nutr. 130: 1026S–1031S, 2000]

2012-06-12T12:42:22 - Annamaria Vernone

Alanyl-glutamine prevents muscle atrophy and glutamine synthetase induction by glucocorticoids., 1996
The aims of this work were to establish whether glutamine infusion via alanyl-glutamine dipeptide provides effective therapy against muscle atrophy from glucorticoids and whether the glucocorticoid induction of glutamine synthetase (GS) is downregulated by dipeptide supplementation. Rats were given hydrocortisone 21-acetate or the dosing vehicle and were infused with alanine (AA) or alanyl-glutamine (AG) at the same concentrations and rates (1.15 mumol.min-1.100 g body wt-1, 0.75 ml/h) for 7 days. Compared with AA infusion in hormone-treated animals, AG infusion prevented total body and fast-twitch muscle mass losses by over 70%. Glucocorticoid treatment did not reduce muscle glutamine levels. Higher serum glutamine was found in the AG-infused (1.72 +/- 0.28 mumol/ml) compared with the AA-infused group (1.32 +/- 0.06 mumol/ml), but muscle glutamine concentrations were not elevated by AG infusion. Following glucocorticoid injections, GS enzyme activity was increased by two- to threefold in plantaris, fast-twitch white (superficial quadriceps), and fast-twitch red (deep quadriceps) muscle/fiber types of the AA group. Similarly, GS mRNA was elevated by 3.3- to 4.1-fold in these same muscles of hormone-treated, AA-infused rats. AG infusion diminished glucocorticoid effects on GS enzyme activity to 52-65% and on GS mRNA to 31-37% of the values with AA infusion. These results provide firsthand evidence of atrophy prevention from a catabolic state using glutamine in dipeptide form. Despite higher serum and muscle alanine levels with AA infusion than with AG infusion, alanine alone is not a sufficient stimulus to counteract muscle atrophy. The AG-induced muscle sparing is accompanied by diminished expression of a glucocorticoid-inducible gene in skeletal muscle. However, glutamine regulation of GS appears complex and may involve more regulators than muscle glutamine concentration alone.

AddThis Social Bookmark Button