Endothelin-converting enzyme-like I (ECEL1; ‘XCE’): a putative metallopeptidase crucially involved in the nervous control of respiration

Endothelin-converting enzyme-like 1 (ECEL1) is a putative zinc metalloprotease that was recently identified on the basis of its strong similarity to endothelin-converting enzyme 1. The physiological function of ECEL1 remains unknown so far; the failure to identify a substrate for ECEL1 could be related to the endoplasmic reticulum subcellular localization found by immunofluorescence in recombinant systems. However, clues to the function of ECEL1 were provided by the in-activation of its gene in mice, which resulted in neonatal lethality. The phenotype of homozygous ECEL1− mice, together with the very specific expression profile of its mRNA in the central nervous system, suggests that ECEL1 is crucially involved in the nervous control of respiration.