Ligand-binding domain of type B natriuretic peptide receptor
Ligand-binding domain of type B natriuretic peptide receptor (NPR-B). NPR-B is one of three known single membrane-spanning natriuretic peptide receptors that have been identified. Natriuretic peptides are family of structurally related but genetically distinct hormones/paracrine factors that regulate blood volume, blood pressure, ventricular hypertrophy, pulmonary hypertension, fat metabolism, and long bone growth. In mammals there are three natriuretic peptides: ANP, BNP, and CNP. Like NPR-A (or GC-A), NPR-B (or GC-B) is a transmembrane guanylyl cyclase, an enzyme that catalyzes the synthesis of cGMP. NPR-B is the predominant natriuretic peptide receptor in the brain. The rank of order activation of NPR-B by natriuretic peptides is CNP>>ANP>BNP. Homozygous inactivating mutations in human NPR-B cause a form of short-limbed dwarfism known as acromesomelic dysplasia type Maroteaux.