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A corin variant identified in hypertensive patients that alters cytoplasmic tail and reduces cell surface expression and activity.

Zhang Y, Li H, Zhou J, Wang A, Yang J, Wang C, Liu M, Zhou T, Zhu L, Zhang Y, Dong N, Wu Q - Sci Rep (2014)

Bottom Line: Corin is a membrane-bound protease that regulates blood pressure by activating the natriuretic peptides.Analysis of two independent cohorts showed that the variant was preferentially present in hypertensive patients (38/795 or 4.78% vs. 4/632 or 0.63% in normal individuals, p = 4.14E-6).In cell-based studies, the corin variant exhibited poor trafficking in the Golgi, reduced cell surface expression and zymogen activation, and low natriuretic peptide processing activity.

View Article: PubMed Central - PubMed

Affiliation: Cyrus Tang Hematology Center, MOE Engineering Center of Hematological Disease, MOH Key Lab of Thrombosis and Hemostasis, Jiangsu Institute of Hematology, the First Affiliated Hospital, and Collaborative Innovation Center of Hematology, Soochow University, Suzhou, China.

ABSTRACT
Corin is a membrane-bound protease that regulates blood pressure by activating the natriuretic peptides. CORIN variants have been associated with hypertension and heart disease in African Americans. In this study, we conducted targeted exome sequencing and identified an insertion variant, c.102_103insA, in exon 1 of the CORIN gene. Analysis of two independent cohorts showed that the variant was preferentially present in hypertensive patients (38/795 or 4.78% vs. 4/632 or 0.63% in normal individuals, p = 4.14E-6). The insertion shifted the reading frame, resulting in a corin variant with a truncated cytoplasmic tail. In cell-based studies, the corin variant exhibited poor trafficking in the Golgi, reduced cell surface expression and zymogen activation, and low natriuretic peptide processing activity. Compared with normal individuals with the wild-type allele, individuals with the variant allele had lower levels of plasma corin [0.59 ± 0.07 ng/mL (n = 25) vs. 0.91 ± 0.02 ng/mL (n = 215), p<0.001] and higher levels of plasma N-terminal pro-atrial natriuretic peptide (NT-pro-ANP) [2.39 ± 3.6 nmol/L (n = 21) vs. 0.87 ± 0.6 nmol/L (n = 48), p = 0.005]. These results indicate that the variant altered corin structure and impaired the natriuretic peptide processing activity in vivo. The results highlight corin defects as an important underlying mechanism in hypertension.

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Shed corin fragments in conditioned medium and plasma levels of soluble corin and NT-pro-ANP.(A) Western analysis of corin fragments in the conditioned medium from cells expressing corin WT, the variant and mutants (upper panel). Corin proteins in cell lysate are shown as a control (lower panel). The cropped blots are used in the main figure and full-length blots are included in the supplementary information (Supplementary Fig. S3). Data are representative of four independent experiments. Western blots were analyzed by densitometry. Percentages of the ~180-kDa corin fragment (B) or all there soluble corin fragments (C) were estimated. Data are mean ± S.D. from four independent experiments. (D) Plasma levels of soluble corin in individuals with WT (Control) and the variant (insA) alleles. (E) Plasma levels of NT-pro-ANP in individuals with WT (Control) and the variant (insA) alleles.
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f6: Shed corin fragments in conditioned medium and plasma levels of soluble corin and NT-pro-ANP.(A) Western analysis of corin fragments in the conditioned medium from cells expressing corin WT, the variant and mutants (upper panel). Corin proteins in cell lysate are shown as a control (lower panel). The cropped blots are used in the main figure and full-length blots are included in the supplementary information (Supplementary Fig. S3). Data are representative of four independent experiments. Western blots were analyzed by densitometry. Percentages of the ~180-kDa corin fragment (B) or all there soluble corin fragments (C) were estimated. Data are mean ± S.D. from four independent experiments. (D) Plasma levels of soluble corin in individuals with WT (Control) and the variant (insA) alleles. (E) Plasma levels of NT-pro-ANP in individuals with WT (Control) and the variant (insA) alleles.

Mentions: As reported previously26, cell surface corin undergoes proteolytic shedding, generating three fragments of ~180-, ~160-, and ~100-kDa, respectively, in the conditioned medium. The ~180-kDa fragment was from a disintegrin and metalloprotease (ADAM)-mediated cleavage, whereas the ~160- and ~100-kDa fragments were from corin autocleavage26. We examined corin shedding in HEK293 cells. Three bands of the predicted sizes were found in the conditioned medium from cells expressing WT (Fig. 6A). In cells expressing the insA variant and the Met-30 isoform, the ~180-kDa fragment was less abundant and the ~100-kDa fragment was hardly visible (Fig. 6A). By densitometric analysis of the Western blots, the percentage of the ~180-kDa fragment (Fig. 6B) or all three soluble corin fragments (Fig. 6C) was significantly lower than that of WT (n = 4, p values <0.01). In inactive mutants R801A and S985A, only the ~180-kDa ADAM-cleaved fragment was detected, but not the ~160- and ~100-kDa autocleavage fragments, as predicted. The results indicate that the insA variant had reduced shedding, likely due to impaired cell surface targeting and zymogen activation.


A corin variant identified in hypertensive patients that alters cytoplasmic tail and reduces cell surface expression and activity.

Zhang Y, Li H, Zhou J, Wang A, Yang J, Wang C, Liu M, Zhou T, Zhu L, Zhang Y, Dong N, Wu Q - Sci Rep (2014)

Shed corin fragments in conditioned medium and plasma levels of soluble corin and NT-pro-ANP.(A) Western analysis of corin fragments in the conditioned medium from cells expressing corin WT, the variant and mutants (upper panel). Corin proteins in cell lysate are shown as a control (lower panel). The cropped blots are used in the main figure and full-length blots are included in the supplementary information (Supplementary Fig. S3). Data are representative of four independent experiments. Western blots were analyzed by densitometry. Percentages of the ~180-kDa corin fragment (B) or all there soluble corin fragments (C) were estimated. Data are mean ± S.D. from four independent experiments. (D) Plasma levels of soluble corin in individuals with WT (Control) and the variant (insA) alleles. (E) Plasma levels of NT-pro-ANP in individuals with WT (Control) and the variant (insA) alleles.
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f6: Shed corin fragments in conditioned medium and plasma levels of soluble corin and NT-pro-ANP.(A) Western analysis of corin fragments in the conditioned medium from cells expressing corin WT, the variant and mutants (upper panel). Corin proteins in cell lysate are shown as a control (lower panel). The cropped blots are used in the main figure and full-length blots are included in the supplementary information (Supplementary Fig. S3). Data are representative of four independent experiments. Western blots were analyzed by densitometry. Percentages of the ~180-kDa corin fragment (B) or all there soluble corin fragments (C) were estimated. Data are mean ± S.D. from four independent experiments. (D) Plasma levels of soluble corin in individuals with WT (Control) and the variant (insA) alleles. (E) Plasma levels of NT-pro-ANP in individuals with WT (Control) and the variant (insA) alleles.
Mentions: As reported previously26, cell surface corin undergoes proteolytic shedding, generating three fragments of ~180-, ~160-, and ~100-kDa, respectively, in the conditioned medium. The ~180-kDa fragment was from a disintegrin and metalloprotease (ADAM)-mediated cleavage, whereas the ~160- and ~100-kDa fragments were from corin autocleavage26. We examined corin shedding in HEK293 cells. Three bands of the predicted sizes were found in the conditioned medium from cells expressing WT (Fig. 6A). In cells expressing the insA variant and the Met-30 isoform, the ~180-kDa fragment was less abundant and the ~100-kDa fragment was hardly visible (Fig. 6A). By densitometric analysis of the Western blots, the percentage of the ~180-kDa fragment (Fig. 6B) or all three soluble corin fragments (Fig. 6C) was significantly lower than that of WT (n = 4, p values <0.01). In inactive mutants R801A and S985A, only the ~180-kDa ADAM-cleaved fragment was detected, but not the ~160- and ~100-kDa autocleavage fragments, as predicted. The results indicate that the insA variant had reduced shedding, likely due to impaired cell surface targeting and zymogen activation.

Bottom Line: Corin is a membrane-bound protease that regulates blood pressure by activating the natriuretic peptides.Analysis of two independent cohorts showed that the variant was preferentially present in hypertensive patients (38/795 or 4.78% vs. 4/632 or 0.63% in normal individuals, p = 4.14E-6).In cell-based studies, the corin variant exhibited poor trafficking in the Golgi, reduced cell surface expression and zymogen activation, and low natriuretic peptide processing activity.

View Article: PubMed Central - PubMed

Affiliation: Cyrus Tang Hematology Center, MOE Engineering Center of Hematological Disease, MOH Key Lab of Thrombosis and Hemostasis, Jiangsu Institute of Hematology, the First Affiliated Hospital, and Collaborative Innovation Center of Hematology, Soochow University, Suzhou, China.

ABSTRACT
Corin is a membrane-bound protease that regulates blood pressure by activating the natriuretic peptides. CORIN variants have been associated with hypertension and heart disease in African Americans. In this study, we conducted targeted exome sequencing and identified an insertion variant, c.102_103insA, in exon 1 of the CORIN gene. Analysis of two independent cohorts showed that the variant was preferentially present in hypertensive patients (38/795 or 4.78% vs. 4/632 or 0.63% in normal individuals, p = 4.14E-6). The insertion shifted the reading frame, resulting in a corin variant with a truncated cytoplasmic tail. In cell-based studies, the corin variant exhibited poor trafficking in the Golgi, reduced cell surface expression and zymogen activation, and low natriuretic peptide processing activity. Compared with normal individuals with the wild-type allele, individuals with the variant allele had lower levels of plasma corin [0.59 ± 0.07 ng/mL (n = 25) vs. 0.91 ± 0.02 ng/mL (n = 215), p<0.001] and higher levels of plasma N-terminal pro-atrial natriuretic peptide (NT-pro-ANP) [2.39 ± 3.6 nmol/L (n = 21) vs. 0.87 ± 0.6 nmol/L (n = 48), p = 0.005]. These results indicate that the variant altered corin structure and impaired the natriuretic peptide processing activity in vivo. The results highlight corin defects as an important underlying mechanism in hypertension.

Show MeSH
Related in: MedlinePlus