Catalyzes the reversible transamination between alanine and 2-oxoglutarate to form pyruvate and glutamate. 2-oxoglutarate + L-alanine = L-glutamate + pyruvate Amino-acid degradation; L-alanine degradation via transaminase pathway; pyruvate from L-alanine: step 1/1. Homodimer. Expressed at high levels in muscle, adipose tissue, kidney and brain and at lower levels in the liver and breast. The disease is caused by variants affecting the gene represented in this entry. Belongs to the class-I pyridoxal-phosphate-dependent aminotransferase family. Alanine aminotransferase subfamily.