Glutamate Pyruvate Transaminase (GPT) Enzyme

This gene encodes cytosolic alanine aminotransaminase 1 (ALT1); also known as glutamate-pyruvate transaminase 1. This enzyme catalyzes the reversible transamination between alanine and 2-oxoglutarate to generate pyruvate and glutamate and, therefore, plays a key role in the intermediary metabolism of glucose and amino acids. Serum activity levels of this enzyme are routinely used as a biomarker of liver injury caused by drug toxicity, infection, alcohol, and steatosis. A related gene on chromosome 16 encodes a putative mitochondrial alanine aminotransaminase.[provided by RefSeq, Nov 2009]

Function: Catalyzes the reversible transamination between alanine and 2-oxoglutarate to form pyruvate and glutamate. Participates in cellular nitrogen metabolism and also in liver gluconeogenesis starting with precursors transported from skeletal muscles

By similarity.

Catalytic activity: L-alanine + 2-oxoglutarate = pyruvate + L-glutamate.

Cofactor: Pyridoxal phosphate.

Pathway: Amino-acid degradation; L-alanine degradation via transaminase pathway; pyruvate from L-alanine: step 1/1.

Subunit structure: Homodimer.

Subcellular location: Cytoplasm.

Tissue specificity: Liver, kidney, heart, and skeletal muscles. Expressed at moderate levels in the adipose tissue. Ref.8

Induction: By glucocorticoids.

Sequence similarities: Belongs to the class-I pyridoxal-phosphate-dependent aminotransferase family. Alanine aminotransferase subfamily.