Disruption of ECE-1 and ECE-2 reveals a role for endothelin-converting enzyme-2 in murine cardiac development.
Endothelin-converting enzyme-1 and -2 (ECE-1 and -2) are membrane-bound metalloproteases that can cleave biologically the inactive endothelin-1 (ET-1) precursor to form active ET-1 in vitro. We previously reported developmental defects in specific subsets of neural crest-derived tissues, including branchial arch-derived craniofacial structures, aortic arch arteries, and the cardiac outflow tract in ECE-1 knockout mice. To examine the role of ECE-2 in cardiovascular development, we have now generated a null mutation in ECE-2 by homologous recombination. ECE-2 null mice develop normally, are healthy into adulthood, are fertile in both sexes, and live a normal life span. However, when they are bred into an ECE-1-null background, defects in cardiac outflow structures become more severe than those in ECE-1 single knockout embryos. In addition, ECE-1(-/-); ECE-2(-/-) double null embryos exhibited abnormal atrioventricular valve formation, a phenotype never seen in ECE-1 single knockout embryos. In the developing mouse heart, ECE-2 mRNA is expressed in the endocardial cushion mesenchyme from embyronic day (E) 12.5, in contrast to the endocardial expression of ECE-1. Levels of mature ET-1 and ET-2 in whole ECE-1(-/-); ECE-2(-/-) embryos at E12.5 do not differ appreciably from those of ECE-1(-/-) embryos. The significant residual ET-1/ET-2 in the ECE-1(-/-); ECE-2(-/-) embryos indicates that proteases distinct from ECE-1 and ECE-2 can carry out ET-1 activation in vivo.
Yanagisawa
H
H
Howard Hughes Medical Institute, Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas 75390-9050, USA.
Hammer
R E
RE
Richardson
J A
JA
Emoto
N
N
Williams
S C
SC
Takeda
S i
Si
Clouthier
D E
DE
Yanagisawa
M
M
D000818:Animals; D016282:Aspartic Acid Endopeptidases / Q000235:genetics* / Q000502:physiology*; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D019332:Endothelin-1 / Q000378:metabolism; D019333:Endothelin-2 / Q000378:metabolism; D000072396:Endothelin-Converting Enzymes; D005260:Female; D005318:Fetal Heart / Q000196:embryology* / Q000201:enzymology*; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D006330:Heart Defects, Congenital / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D017403:In Situ Hybridization; D066298:In Vitro Techniques; D008297:Male; D008666:Metalloendopeptidases / Q000235:genetics* / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D011247:Pregnancy; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014018:Tissue Distribution
D017931:DNA Primers; D019332:Endothelin-1; D019333:Endothelin-2; D012333:RNA, Messenger; D016282:Aspartic Acid Endopeptidases; D008666:Metalloendopeptidases; C000606925:Ece1 protein, mouse; C000606926:Ece2 protein, mouse; D000072396:Endothelin-Converting Enzymes