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MetaCyc Enzyme: glutaminase, liver isoform

Gene: Gls2 Accession Number: G-9955 (MetaCyc)

Species: Rattus norvegicus

Subunit composition of glutaminase, liver isoform = [Gls2]3
         glutaminase subunit = Gls2

Summary:
The relative molecular mass of native glutaminase from Rattus norvegicus was estimated by sucrose density gradient ultracentrifugation [Heini87].

In mammals, two mitochondrial isoforms of glutaminase, liver isoform and kidney isoform, have been characterized. These two isoforms have different kinetic and molecular properties and are encoded by different genes. In Rattus norvegicus the kidney isoform is encoded by gene Gls and the liver isoform by gene Gls2. The liver isoform is expressed in post-natal liver, pancreas and brain. The kidney isoform is abundant in cells of the kidney, brain, intestinal epithelium, fetal liver, and in lymphocytes (in [Kenny03]). A third, nuclear isoform resembling the liver isoform has been characterized in mammalian brain, with properties distinct from the liver and kidney isoforms [Olalla02].

Glutaminases are present in both eukaryotes and prokaryotes and play important roles in nitrogen metabolism by effecting glutamine breakdown. Eukaryotic glutaminases differ in properties from those of prokaryotes. Phosphate activation is characteristic of eukaryotic enzymes, although a phosphate-activated glutaminase has been characterized from Sporosarcina pasteurii (previously known as Bacillus pasteurii) [Klein02] (see glutaminase).
The relative molecular mass of the glutaminase subunit from Rattus norvegicus was estimated by sucrose density gradient ultracentrifugation [Heini87].

Gene Citations: [ChungBok97]

Locations: mitochondrion

Map Position: [1,484,397 -> 1,495,289]

Molecular Weight of Polypeptide: 66.248 kD (from nucleotide sequence), 57 kD (experimental) [Heini87 ]

Molecular Weight of Multimer: 172.5 kD (experimental) [Heini87]

Unification Links: Entrez-gene:192268 , Pride:P28492 , Protein Model Portal:P28492 , SMR:P28492 , String:P28492 , UniProt:P28492

Relationship Links: InterPro:IN-FAMILY:IPR002110 , InterPro:IN-FAMILY:IPR012338 , InterPro:IN-FAMILY:IPR015868 , InterPro:IN-FAMILY:IPR020683 , Panther:IN-FAMILY:PTHR12544 , Pfam:IN-FAMILY:PF04960 , Pfam:IN-FAMILY:PF12796 , Prosite:IN-FAMILY:PS50088 , Prosite:IN-FAMILY:PS50297 , Smart:IN-FAMILY:SM00248

Gene-Reaction Schematic: ?

GO Terms:

Cellular Component: GO:0005739 - mitochondrion [Heini87]

Credits:
Created 08-Mar-2007 by Fulcher CA , SRI International


Enzymatic reaction of: glutaminase

Synonyms: glutamine aminohydrolase

EC Number: 3.5.1.2

L-glutamine + H2O <=> L-glutamate + ammonium

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.

The reaction is physiologically favored in the direction shown.

In Pathways: glutamine degradation I , citrulline biosynthesis

Summary:
The activity of Rattus norvegicus glutaminase, liver isoform, was dependent on added phosphate. It required ammonia as an activator and showed a sigmoidal concentration dependence on glutamine [Patel84].

Activators (Unknown Mechanism): ammonium [Patel84]

pH(opt): 7.7-8.5 [Patel84]


References

ChungBok97: Chung-Bok MI, Vincent N, Jhala U, Watford M (1997). "Rat hepatic glutaminase: identification of the full coding sequence and characterization of a functional promoter." Biochem J 324 ( Pt 1);193-200. PMID: 9164856

Heini87: Heini HG, Gebhardt R, Brecht A, Mecke D (1987). "Purification and characterization of rat liver glutaminase." Eur J Biochem 162(3);541-6. PMID: 3830157

Kenny03: Kenny J, Bao Y, Hamm B, Taylor L, Toth A, Wagers B, Curthoys NP (2003). "Bacterial expression, purification, and characterization of rat kidney-type mitochondrial glutaminase." Protein Expr Purif 31(1);140-8. PMID: 12963351

Klein02: Klein M, Kaltwasser H, Jahns T (2002). "Isolation of a novel, phosphate-activated glutaminase from Bacillus pasteurii." FEMS Microbiol Lett 206(1);63-7. PMID: 11786258

Olalla02: Olalla L, Gutierrez A, Campos JA, Khan ZU, Alonso FJ, Segura JA, Marquez J, Aledo JC (2002). "Nuclear localization of L-type glutaminase in mammalian brain." J Biol Chem 277(41);38939-44. PMID: 12163477

Patel84: Patel M, McGivan JD (1984). "Partial purification and properties of rat liver glutaminase." Biochem J 220(2);583-90. PMID: 6743288


Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by SRI International Pathway Tools version 18.5 on Fri Dec 19, 2014, BIOCYC13B.