title: Corin variant associated with hypertension and cardiac hypertrophy exhibits impaired zymogen activation and natriuretic peptide processing activity.
abstract: Corin is a cardiac serine protease that acts as the pro-atrial natriuretic peptide (ANP) convertase. Recently, 2 single-nucleotide polymorphisms (SNPs) (T555I and Q568P) in the human corin gene have been identified in genetic epidemiological studies. The minor I555/P568 allele, which is more common in African Americans, is associated with hypertension and cardiac hypertrophy. In this study, we examined the effect of T555I and Q568P amino acid substitutions on corin function. We found that corin frizzled-like domain 2, where T555I/Q568P substitutions occur, was required for efficient pro-ANP processing in functional assays. Mutant corin lacking this domain had 30+/-5% (P<0.01) activity compared to that of wild type. Similarly, corin variant T555I/Q568P had a reduced (38+/-7%, P<0.01) pro-ANP processing activity compared to that of wild type. The variant also exhibited a low activity (44+/-15%, P<0.05) in processing pro-brain natriuretic peptide (BNP). We next examined the biochemical basis for the loss of activity in T555I/Q568P variant and found that the zymogen activation of the corin variant was impaired significantly, as indicated by the absence of the activated protease domain fragment. This finding was confirmed in human embryonic kidney (HEK)293 cells and murine HL-1 cardiomyocytes. Thus, our results show that the corin gene SNPs associated with hypertension and cardiac hypertrophy impair corin zymogen activation and natriuretic peptide processing activity. Our data suggest that corin deficiency may be an important mechanism in hypertensive and heart diseases.
authors.affiliation: Molecular Cardiology, Cleveland Clinic, 9500 Euclid Ave, Cleveland, OH 44195, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Xudong
authors.initials: X
authors.lastname: Liao
authors.forename: Koichi
authors.initials: K
authors.lastname: Fukuda
authors.forename: Sabine
authors.initials: S
authors.lastname: Knappe
authors.forename: Faye
authors.initials: F
authors.lastname: Wu
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Dries
authors.forename: Jun
authors.initials: J
authors.lastname: Qin
authors.forename: Qingyu
authors.initials: Q
authors.lastname: Wu
mesh_terms: D009320:Atrial Natriuretic Factor / Q000378:metabolism; D006332:Cardiomegaly / Q000378:metabolism* / Q000503:physiopathology; D002460:Cell Line; D004792:Enzyme Precursors / Q000378:metabolism*; D014644:Genetic Variation; D006801:Humans; D006973:Hypertension / Q000378:metabolism* / Q000503:physiopathology; D007668:Kidney / Q000166:cytology; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016296:Mutagenesis; D020097:Natriuretic Peptide, Brain / Q000378:metabolism; D045265:Natriuretic Peptides / Q000378:metabolism*; D020641:Polymorphism, Single Nucleotide; D017434:Protein Structure, Tertiary; D012697:Serine Endopeptidases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D013379:Substrate Specificity; D014162:Transfection
chemical_list: D004792:Enzyme Precursors; D008565:Membrane Proteins; D045265:Natriuretic Peptides; D020097:Natriuretic Peptide, Brain; D009320:Atrial Natriuretic Factor; C119812:CORIN protein, human; D012697:Serine Endopeptidases