Subchapter 46C - C-type natriuretic peptides

Abstract

C-type natriuretic peptides (CNPs) are NP members that lack the C-terminal tail sequence extending from the intramolecular ring. CNPs are categorized into four types (CNP1–4) based on the molecular phylogenetic study, and different types of the CNP gene are retained in each vertebrate class. Mature CNPs are highly conserved among species. CNPs are abundantly expressed in the brain and act as a paracrine/autocrine factor rather than an endocrine hormone (except for chondrichthyes and cyclostomes, in which CNPs have both roles). CNPs bind to NPR-B/GC-B that mediates the synthesis of the second messenger cGMP. Although the action of CNP in the brain has yet to be determined, knockout studies revealed that CNP regulates long bone growth via action on the chondrocytes. CNP is also known as a vasodilator in various species. From a comparative perspective, the discovery of the four CNP genes from teleostean genome databases provides an important clue to understanding the molecular evolution of the NP family.