User:NeednAdvil/sandbox

ANP is synthesized as an inactive preprohormone, encoded by the human NPPA gene located on the short arm of chromosome 1. The NPPA gene is expressed primarily in atrial myocytes and comprises of 2 introns and 3 exons, with translation of this gene yielding a high molecular mass 151 amino acid polypeptide known as preproANP. The preprohormone is activated via post-translational modification that involves cleavage of the 25 amino acid signal sequence to produce proANP, a 126 amino acid peptide that is the major form of ANP stored in intracellular granules of the atria. Following stimulation of atrial cells, proANP is released and rapidly converted to the 28-amino-acid C-terminal mature ANP on the cell surface by the cardiac transmembrane serine protease corin.