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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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Cell surface expression of corin proteins.(A) Western analysis of biotin-labeled corin proteins on the cell surface (left panel) and in cell lysate (right panel). GAPDH was used as a control (lower panels). The cropped blots are used in the main figure and full-length blots are included in the supplementary information (Supplementary Fig. S2). (B) Corin bands on Western blots were analyzed by densitometry. Percentage of corin proteins on the cell surface was estimated. Data are mean ± S.D. from three independent experiments. (C) Analysis of cell surface corin proteins by flow cytometry. Data are representative of three independent experiments.
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f4: Cell surface expression of corin proteins.(A) Western analysis of biotin-labeled corin proteins on the cell surface (left panel) and in cell lysate (right panel). GAPDH was used as a control (lower panels). The cropped blots are used in the main figure and full-length blots are included in the supplementary information (Supplementary Fig. S2). (B) Corin bands on Western blots were analyzed by densitometry. Percentage of corin proteins on the cell surface was estimated. Data are mean ± S.D. from three independent experiments. (C) Analysis of cell surface corin proteins by flow cytometry. Data are representative of three independent experiments.

Mentions: Corin is a membrane-bound protease and its activation depends on cell surface expression14. Previous studies indicated that cytoplasmic tail sequences may alter corin cell surface expression15. We examined the variant expression in biotin-labeled HEK293 cells. Surface expression of the insA variant was much less abundant than that of WT (5.5 ± 1.5 vs. 31.5 ± 8.4%, n = 3, p<0.01) (Fig. 4A and B). Similarly reduced cell surface expression was observed in the Met-30 isoform (6.7 ± 3.1%, n = 3, p<0.01 vs. WT) (Fig. 4A and B). As controls, the cell surface expression of mutants R801A and S985A was similar to that of WT (Fig. 4A). In cell lysate, total corin levels were comparable in all samples (Fig. 4A, right panel). As expected, GAPDH was absent in labeled cell surface proteins, but present at similar levels in all lysate samples (Fig. 4A, lower panels).


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)

Cell surface expression of corin proteins.(A) Western analysis of biotin-labeled corin proteins on the cell surface (left panel) and in cell lysate (right panel). GAPDH was used as a control (lower panels). The cropped blots are used in the main figure and full-length blots are included in the supplementary information (Supplementary Fig. S2). (B) Corin bands on Western blots were analyzed by densitometry. Percentage of corin proteins on the cell surface was estimated. Data are mean ± S.D. from three independent experiments. (C) Analysis of cell surface corin proteins by flow cytometry. Data are representative of three independent experiments.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4260221&req=5

f4: Cell surface expression of corin proteins.(A) Western analysis of biotin-labeled corin proteins on the cell surface (left panel) and in cell lysate (right panel). GAPDH was used as a control (lower panels). The cropped blots are used in the main figure and full-length blots are included in the supplementary information (Supplementary Fig. S2). (B) Corin bands on Western blots were analyzed by densitometry. Percentage of corin proteins on the cell surface was estimated. Data are mean ± S.D. from three independent experiments. (C) Analysis of cell surface corin proteins by flow cytometry. Data are representative of three independent experiments.
Mentions: Corin is a membrane-bound protease and its activation depends on cell surface expression14. Previous studies indicated that cytoplasmic tail sequences may alter corin cell surface expression15. We examined the variant expression in biotin-labeled HEK293 cells. Surface expression of the insA variant was much less abundant than that of WT (5.5 ± 1.5 vs. 31.5 ± 8.4%, n = 3, p<0.01) (Fig. 4A and B). Similarly reduced cell surface expression was observed in the Met-30 isoform (6.7 ± 3.1%, n = 3, p<0.01 vs. WT) (Fig. 4A and B). As controls, the cell surface expression of mutants R801A and S985A was similar to that of WT (Fig. 4A). In cell lysate, total corin levels were comparable in all samples (Fig. 4A, right panel). As expected, GAPDH was absent in labeled cell surface proteins, but present at similar levels in all lysate samples (Fig. 4A, lower panels).

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