1. Academic Validation
  2. Golgi α-Mannosidases Regulate Cell Surface N-Glycan Type and Ectodomain Shedding of the Transmembrane Protease Corin

Golgi α-Mannosidases Regulate Cell Surface N-Glycan Type and Ectodomain Shedding of the Transmembrane Protease Corin

  • J Biol Chem. 2023 Sep 1;105211. doi: 10.1016/j.jbc.2023.105211.
Hao Wang 1 Yi-Shi Liu 2 Yingfei Peng 1 Wei Chen 1 Ningzheng Dong 3 Qingyu Wu 4 Baishen Pan 1 Beili Wang 5 Wei Guo 6
Affiliations

Affiliations

  • 1 Department of Laboratory Medicine, Zhongshan Hospital, Fudan University, China.
  • 2 Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China.
  • 3 Cyrus Tang Hematology Center, Collaborative Innovation Center of Hematology, State Key Laboratory of Radiation Medicine and Prevention, Soochow University, Suzhou, China; NHC Key Laboratory of Thrombosis and Hemostasis, Jiangsu Institute of Hematology, The First Affiliated Hospital of Soochow University, Suzhou, China.
  • 4 Cyrus Tang Hematology Center, Collaborative Innovation Center of Hematology, State Key Laboratory of Radiation Medicine and Prevention, Soochow University, Suzhou, China.
  • 5 Department of Laboratory Medicine, Zhongshan Hospital, Fudan University, China; Cancer Center, Shanghai Zhongshan Hospital, Fudan University, Shanghai, China; Department of Laboratory Medicine, Xiamen Branch, Zhongshan Hospital, Fudan University, China; Department of Laboratory Medicine, Wusong Branch, Zhongshan Hospital, Fudan University, China; Branch of National Clinical Research Center for Laboratory Medicine, China. Electronic address: wang.beili1@zs-hospital.sh.cn.
  • 6 Department of Laboratory Medicine, Zhongshan Hospital, Fudan University, China; Cancer Center, Shanghai Zhongshan Hospital, Fudan University, Shanghai, China; Department of Laboratory Medicine, Xiamen Branch, Zhongshan Hospital, Fudan University, China; Department of Laboratory Medicine, Wusong Branch, Zhongshan Hospital, Fudan University, China; Branch of National Clinical Research Center for Laboratory Medicine, China. Electronic address: zs-guowei@hotmail.com.
Abstract

Corin is a transmembrane protease that activates natriuretic Peptides on the cell membrane. Reduced cell surface targeting or increased ectodomain shedding disrupts cell membrane homeostasis of corin, thereby impairing its cell surface expression and Enzyme activity. N-glycans are essential in corin ectodomain shedding. Lack of N-glycans promotes corin ectodomain shedding in the juxtamembrane and Frizzled-1 domains. The nascent N-glycans, transferred onto the polypeptide of corin, undergo multi-step N-glycan processing in the endoplasmic reticulum and Golgi. It remains unclear how trimming by Golgi α-mannosidases, the critical N-glycan processing steps in N-glycan maturation, may regulate corin biosynthesis. In this study, we examined the effects of kifunensine and swainsonine, the inhibitors for α-mannosidases I and II, on corin expression and function. Western analysis of corin proteins in cell lysates and conditioned media from the inhibitor-treated corin-stable HEK293 cells and AC16 cells showed that both α-mannosidases I and II were required to maintain complex N-glycans on cell surface corin and protect corin from ectodomain shedding in the juxtamembrane and Frizzled-1 domains. Cell viability analysis revealed that inhibition of α-mannosidase I or II sensitized cardiomyocytes to H2O2-induced injury via regulating corin. Moreover, either one of the two coding genes was sufficient to perform Golgi α-mannosidase I trimming of N-glycans on corin. Similarly, this sufficiency was observed in Golgi α-mannosidase II-coding genes. Inhibition of ectodomain shedding restored corin zymogen activation from kifunensine- or swainsonine-induced reduction. Together, our results show the important roles of Golgi α-mannosidases in maintaining cell membrane homeostasis and biological activities of corin.

Keywords

Corin; Dysfunction; Ectodomain Shedding; Mannosidase; N-Glycan.

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