Identification of a Mitochondrial Form of Kynurenine aminotransferase/glutamine Transaminase K From Rat Brain

FEBS Lett. 1995 Jun 26;367(2):141-4. doi: 10.1016/0014-5793(95)00546-l.

Abstract

A soluble aminotransferase with kynurenine aminotransferase (KAT) activity has been recently isolated from rat brain. This enzyme corresponds to a cytosolic form of glutamine transaminase K (GTK). In addition to the cytosolic enzyme, a mitochondrial-associated form of this KAT/GTK also exists. In the present work we have isolated a rat brain cDNA clone encoding a KAT/GTK enzyme identical to the soluble form but carrying an additional stretch of 32 amino acids at its NH2-terminus. Several structural features of this sequence resemble those of leader peptides for mitochondrial import. Evidence that the isolated cDNA encoded for mitochondrial KAT/GTK was obtained after transfection of HEK-293 cells with the cDNA coding for this new KAT/GTK isoenzyme. In fact, a significant enrichment of both KAT and GTK enzymatic activities was found in the crude mitochondrial fraction of the transfected cells.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Brain / enzymology*
  • Cell Line
  • Cloning, Molecular
  • DNA, Complementary / genetics
  • Gene Expression
  • Lyases / chemistry
  • Lyases / genetics*
  • Lyases / metabolism
  • Mitochondria / enzymology*
  • Molecular Sequence Data
  • Rats
  • Transaminases / chemistry
  • Transaminases / genetics*
  • Transaminases / metabolism
  • Transfection

Substances

  • DNA, Complementary
  • Transaminases
  • glutamine - phenylpyruvate transaminase
  • kynurenine-oxoglutarate transaminase
  • Lyases

Associated data

  • GENBANK/S61960
  • GENBANK/Z49696