CCAP, the most conserved neuropeptide found in arthropods, has been identified in various insects and crustaceans as a factor in cardioacceleratory action. It is also expressed in a conserved network of segmental neurons that controls ecdysis.
CCAP is a cyclic amidated nonapeptide, including two Cys residues that form a disulfide bond. Amidation is crucial for biological activity.
The crustacean cardioactive peptide (CCAP) was originally identified from the central nervous system (CNS) of the crab Carcinus maenas, based on its heart stimulatory activity.An identical neuropeptide and the gene encoding a single copy of CCAP were later identified or annotated in many other insects and crustaceans.
CCAP acts on the heart to elicit increased frequency and amplitude of the heartbeat in crustaceans and insects.Its main central role is to induce the specific ecdysis behavior in moths.In R. prolixus, CCAP proved to be essential for successful ecdysis and development.Also, physiological and genetic experiments indicate that CCAP acts together with myoinhibitory peptides and the bursicon subunit (pburs) to control ecdysis behavior.In feeding cockroaches, CCAP is released from midgut endocrine cells to stimulate α-amylase and protease activity in the intestine.
