title: Absence of cell surface expression of human ACE leads to perinatal death.
abstract: Renal tubular dysgenesis (RTD) is a recessive autosomal disease characterized most often by perinatal death. It is due to the inactivation of any of the major genes of the renin-angiotensin system (RAS), one of which is the angiotensin I-converting enzyme (ACE). ACE is present as a tissue-bound enzyme and circulates in plasma after its solubilization. In this report, we present the effect of different ACE mutations associated with RTD on ACE intracellular trafficking, secretion and enzymatic activity. One truncated mutant, R762X, responsible for neonatal death was found to be an enzymatically active, secreted form, not inserted in the plasma membrane. In contrast, another mutant, R1180P, was compatible with life after transient neonatal renal insufficiency. This mutant was located at the plasma membrane and rapidly secreted. These results highlight the importance of tissue-bound ACE versus circulating ACE and show that the total absence of cell surface expression of ACE is incompatible with life. In addition, two missense mutants (W594R and R828H) and two truncated mutants (Q1136X and G1145AX) were also studied. These mutants were neither inserted in the plasma membrane nor secreted. Finally, the structural implications of these ACE mutations were examined by molecular modelling, which suggested some important structural alterations such as disruption of intra-molecular non-covalent interactions (e.g. salt bridges).
authors.affiliation: Collège de France, Center for Interdisciplinary Research in Biology (CIRB), 11 Place Marcelin Berthelot, Paris F-75005, France.
authors.forename: Annie
authors.initials: A
authors.lastname: Michaud
authors.forename: K Ravi
authors.initials: KR
authors.lastname: Acharya
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Masuyer
authors.forename: Nicole
authors.initials: N
authors.lastname: Quenech'du
authors.forename: Olivier
authors.initials: O
authors.lastname: Gribouval
authors.forename: Vincent
authors.initials: V
authors.lastname: Morinière
authors.forename: Marie-Claire
authors.initials: MC
authors.lastname: Gubler
authors.forename: Pierre
authors.initials: P
authors.lastname: Corvol
mesh_terms: D000818:Animals; D016466:CHO Cells; D003412:Cricetulus; D018360:Crystallography, X-Ray; D005260:Female; D005313:Fetal Death / Q000235:genetics*; D057809:HEK293 Cells; D006801:Humans; D007231:Infant, Newborn; D007687:Kidney Tubules, Proximal / Q000002:abnormalities*; D008297:Male; D008958:Models, Molecular; D020125:Mutation, Missense; D007703:Peptidyl-Dipeptidase A / Q000097:blood / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D021381:Protein Transport; D014564:Urogenital Abnormalities / Q000235:genetics*
chemical_list: C488034:ACE protein, human; D007703:Peptidyl-Dipeptidase A