The prokineticins: a novel pair of regulatory peptides.

Secreted peptides play broad regulatory roles in brain function and elsewhere in the body. Prokineticins are a pair of newly identified regulatory peptides that signal through two highly homologous G protein-coupled receptors. Prokineticins possess a unique structural motif of five disulfide bonds and a completely conserved N-terminal hexapeptide sequence that is essential to biological activity. Diverse biological functions, including roles in development and cell differentiation, have been assigned to the prokineticins. A network of genes, subject to various transcriptional factors, may functionally converge on the prokineticins as regulatory targets.