C. Mercure et al., MOLECULAR ANALYSIS OF HUMAN PRORENIN PROSEGMENT VARIANTS IN-VITRO ANDIN-VIVO, The Journal of biological chemistry, 270(27), 1995, pp. 16355-16359
The aspartyl protease renin, an important modulator of blood pressure
in humans, is present in the circulation not only in its active form,
but also as an inactive precursor, prorenin, in which a 43-amino acid
prosegment blocks access of the substrate to the active site of the en
zyme, Site-directed mutagenesis of the prosegment has led to the follo
wing conclusions. 1) Maintenance of the enzymatically inactive state o
f prorenin requires a short peptide sequence between positions 10P and
20P (where P denotes prosegment and numbering is relative to amino te
rminus) of the prosegment; and 2) there is an inverse relationship bet
ween the ability of prosegment mutations to activate and their effect
on the secretion of the various prorenins, suggesting that this same r
egion of the prosegment plays a critical role in the biosynthesis of h
uman prorenin, Since these results demonstrated that single amino acid
mutations could activate human prorenin to varying degrees, mutations
in this region of the renin gene could be clinically important in hum
ans. To test this hypothesis, genomic screening was carried out on the
corresponding region of the human renin gene (exon 2) in a cohort of
patients selected for a likely familial component to their hypertensio
n. While this study identified a novel polymorphism in exon 2 of the h
uman renin gene, evidence was not obtained for either the presence of
prosegment mutations or the association of the novel polymorphism with
hypertension in the patient population studied. In conclusion, both s
tructure-function studies and genetic screening suggest that mutation
of the prorenin prosegment is an unlikely factor in activation of the
renin-angiotensin system in humans.