Molecular cloning of rat kynurenine aminotransferase: Identity with glutamine transaminase K

Mosca, Monica; Cozzi, Liviana; Breton, Jérôme; Speciale, C.; Okuno, Etsuo; Schwarcz, Robert; Benatti, Luca

doi:10.1016/0014-5793(94)01003-x

Cited by 58 publications

(33 citation statements)

References 14 publications

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“…The membrane was hybridized with 5'-end 32p-labeled been found that this protein corresponds to a cytosolic form of probe (5'-AGGAGCAGGGCTCGGCTTCAGAGTCACGAA-Y). rat kidney glutamine transaminase K (GTK; EC 2.6.1.14) [5,6].…”

Section: Rt-pcr and Southern Blotmentioning

confidence: 99%

“…Judging from the amount in the 5'-untranslated region. This insertion created a new initiof PCR-product from the three tissues examined, the mRNAs ation codon (ATG) and encoded a NH2-terminal stretch of 32 encoding both forms appeared to be expressed with approxiamino acids in frame with the previous open reading frame of mately equal abundance in rat cerebellum, while the shorter rat S-KATIGTK [4][5][6]. The amino acid sequence deduced from (soluble) form (S-KAT/GTK) was predominant in primary culthis longer rat brain cDNA clone consisted of 455 amino acids tures of cortical neurons and astrocytes.…”

Section: Isolation Of Cdna Encoding Membrane-associated Form Ofmentioning

confidence: 99%

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Identification of a mitochondrial form of kynurenine aminotransferase/glutamine transaminase K from rat brain

et al. 1995

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A soluble aminotransferase with kynurenine amiconjugate fl-lyase activity [5,7] and has also been referred to notransferase (KAT) activity has been recently isolated from rat under this nomenclature. Due to its fl-lyasic activity, this brain. This enzyme corresponds to a cytosolic form of glutamine enzyme may be involved in the renal and cerebral toxicity of transaminase K (GTK). In addition to the cytosolic enzyme, a mitoehondrial-associated form of this KATIGTK also exists. In several halogenated xenobiotics [8]. The human form of kidney the present work we have isolated a rat brain cDNA clone encodcytosolic cysteine-S-conjugate fl-lyase/GTK has been recently ing a KATIGTK enzyme identical to the soluble form but carrying cloned and shown to have 82% amino acid similarity to the rat an additional stretch of 32 amino acids at its NH2-terminus.form [9]. Several structural features of this sequence resemble those of In addition to the soluble cytosolic enzyme (S-KAT/GTK), leader peptides for mitochondrial import. Evidence that the isothe existence of a mitochondrial KAT/GTK located in the lated cDNA encoded for mitochondrial KATIGTK was obtained matrix of mitochondria [10] has also been reported. Interestafter transfection of HEK-293 cells with the cDNA coding for ingly, mitochondrial GTK activity appears to be predominantly this new KATIGTK isoenzyme. In fact, a significant enrichment in rat brain, whereas the opposite is true for peripheral organs of both KAT and GTK enzymatic activities was found in the crude such as kidney [11]. In the present work, we report the isolation mitochondrial fraction of the transfected cells.of a rat brain cDNA clone encoding a mitochondrial-associated

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Section: Rt-pcr and Southern Blotmentioning

confidence: 99%

Section: Isolation Of Cdna Encoding Membrane-associated Form Ofmentioning

confidence: 99%

Identification of a mitochondrial form of kynurenine aminotransferase/glutamine transaminase K from rat brain

et al. 1995

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“…The enzyme catalyses the transamination of -kynurenine and 3-hydroxykynurenine to kynurenic acid (KA) and xanthurenic acid (XA) respectively. In mammals, KAT is a multispecific enzyme that also has glutamine transaminase K (GTK) and aminoadipate aminotransferase (AAT) activities [1][2][3]. GTK is regarded as a fully reversible glutamine-methionine or phenylalanine-methionine aminotransferase in mammals [4].…”

Section: Introductionmentioning

confidence: 99%

“…KAT sequences have been determined in human, mouse and rat [3,[14][15][16]. Some sequence data deposited in the National Center for Biotechnology Information (NCBI) protein database (accession numbers T21518, T23861, S56832 and AAK97625) have also been described as KATs, due apparently to their similarities with those of mammalian KATs.…”

Section: Introductionmentioning

confidence: 99%

Kynurenine aminotransferase and glutamine transaminase K of Escherichia coli: identity with aspartate aminotransferase

HAN

Fang

2001

Biochemical Journal

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The present study describes the isolation of a protein from Escherichia coli possessing kynurenine aminotransferase (KAT) activity and its identification as aspartate aminotransferase (AspAT). KAT catalyses the transamination of kynurenine and 3-hydroxykynurenine to kynurenic acid and xanthurenic acid respectively, and the enzyme activity can be easily detected in E. coli cells. Separation of the E. coli protein possessing KAT activity through various chromatographic steps led to the isolation of the enzyme. N-terminal sequencing of the purified protein determined its first 10 N-terminal amino acid residues, which were identical with those of the E. coli AspAT. Recombinant AspAT (R-AspAT), homologously expressed in an E. coli/pET22b expression system, was capable of catalysing the transamination of both l-kynurenine (Km = 3mM; Vmax = 7.9μmol·min−1·mg−1) and 3-hydroxy-dl-kynurenine (Km = 3.7mM; Vmax = 1.25μmol·min−1·mg−1) in the presence of pyruvate as an amino acceptor, and exhibited its maximum activity at temperatures between 50–60°C and at a pH of approx. 7.0. Like mammalian KATs, R-AspAT also displayed high glutamine transaminase K activity when l-phenylalanine was used as an amino donor (Km = 8mM; Vmax = 20.6μmol·min−1·mg−1). The exact match of the first ten N-terminal amino acid residues of the KAT-active protein with that of AspAT, in conjunction with the high KAT activity of R-AspAT, provides convincing evidence that the identity of the E. coli protein is AspAT.

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“…It is known that cysteine conjugate fl-lyase/GTK is present in brain [6] where its function may be related to ammonia metabolism [6]. However, the finding that the enzyme also possesses kyneurenine amino transferase (KAT) activity [7] raises the possibility that it may play a role in neurotransmission via modulation of the NMDA *Corresponding author. Fax: (44) (483) 576978.…”

Section: Introductionmentioning

confidence: 99%

Molecular cloning and expression of a cDNA for human kidney cysteine conjugate β‐lyase

et al. 1995

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Kidney cysteine conjugate i~-lyase (glutamine transaminase K, kyneurenine aminotransferase, EC 2.6.1.64) metabolises the cysteine conjugates of certain halogenated alkenes and alkanes to form reactive metabolites which can produce nephrotoxicicity and neurotoxicicity in experimental animals and man. Using a combination of hybridisation screening and PCR techniques we have isolated a full-length cDNA for human kidney cysteine conjugate i~-lyase. Comparison of the deduced amino acid sequence with that of the rat enzyme indicated an 82% overall similarity, with 90% similarity around the pyridoxal phosphate binding site, many of the changes being conservative in nature. Expression of the cDNA in Cos-1 cells resulted in the production of a cytosolic enzyme which showed both cysteine conjugate ~-lyase and glutamine transaminase K activity. Preliminary mapping of the gene for human cysteine conjugate ~-lyase by PCR analysis of genomic DNA from human-rodent hybrid cells indicated that it is located on human chromosome 9.

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Molecular cloning of rat kynurenine aminotransferase: Identity with glutamine transaminase K

Cited by 58 publications

References 14 publications

Identification of a mitochondrial form of kynurenine aminotransferase/glutamine transaminase K from rat brain

Identification of a mitochondrial form of kynurenine aminotransferase/glutamine transaminase K from rat brain

Kynurenine aminotransferase and glutamine transaminase K of Escherichia coli: identity with aspartate aminotransferase

Molecular cloning and expression of a cDNA for human kidney cysteine conjugate β‐lyase

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