preproANP

PreproANP refers to the precursor protein of atrial natriuretic peptide (ANP). ANP is a hormone that plays a crucial role in regulating blood pressure and fluid balance within the body. The preproANP molecule is synthesized in the cardiac atria, specifically in the atrial myocytes. It is an 126-amino acid polypeptide that undergoes several processing steps to become biologically active. Initially, the preproANP is synthesized as a transmembrane protein with a signal peptide. This signal peptide is cleaved off during translocation into the endoplasmic reticulum, yielding proANP. ProANP, a 108-amino acid peptide, is then transported to the Golgi apparatus where it is further processed. The mature and biologically active form of ANP is generated by proteolytic cleavage of proANP, releasing a 28-amino acid peptide. This mature ANP is stored in secretory granules within atrial myocytes and is released into the bloodstream in response to atrial stretch, which is often caused by increased blood volume or pressure. Once released, ANP acts on the kidneys, blood vessels, and adrenal glands to promote natriuresis (excretion of sodium), diuresis (excretion of water), and vasodilation, all of which contribute to lowering blood pressure and reducing blood volume. Therefore, preproANP is the initial, inactive form that sets in motion the cascade leading to the production of a vital cardiovascular regulator.