Aminopeptidase O (APO)

APO encodes a member of the M1 zinc aminopeptidase family. The encoded protein is a zinc-dependent metallopeptidase that catalyzes the removal of an amino acid from the amino terminus of a protein or peptide. This protein may play a role in the generation of angiotensin IV. Alternate splicing results in multiple transcript variants. Predominantly expressed in pancreas, placenta, liver, testis and heart. Expressed at lower level in brain, lung and kidney. Aminopeptidases catalyze the hydrolysis of amino acid residues from the N-terminus of peptide or protein substrates. Able to cleave angiotensin III to generate angiotensin IV, a bioactive peptide of the renin-angiotensin pathway. Not able to cleave angiotensin I and angiotensin II. May play a role in the proteolytic processing of bioactive peptides in tissues such as testis and heart.