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. Specifically induced in fatty liver. Highly expressed in muscle, liver and white adipose tissue. Moderately expressed in brain and kidney and expressed at low levels in the heart. May be responsible for increased ALT activity in hepatic steatosis. Belongs to the class-I pyridoxal-phosphate-dependent aminotransferase family. Alanine aminotransferase subfamily.