Thromb Haemost 2011; 105(01): 21-30
DOI: 10.1160/TH10-07-0446
Blood Coagulation, Fibrinolysis and Cellular Haemostasis
Schattauer GmbH

Cysteine residues in CUB-1 domain are critical for ADAMTS13 secretion and stability

Zhou Zhou
1   Section of Cardiovascular Sciences, Department of Medicine, Baylor College of Medicine, Houston, Texas, USA
,
Hui-Chun Yeh
1   Section of Cardiovascular Sciences, Department of Medicine, Baylor College of Medicine, Houston, Texas, USA
,
Hua Jing
2   Center for Membrane Biology, Department of Biochemistry and Molecular Biology, University of Texas Health Science Center at Houston, Houston, Texas, USA
,
Christina Wang
1   Section of Cardiovascular Sciences, Department of Medicine, Baylor College of Medicine, Houston, Texas, USA
,
Zhenyin Tao
1   Section of Cardiovascular Sciences, Department of Medicine, Baylor College of Medicine, Houston, Texas, USA
,
Huiwan Choi
1   Section of Cardiovascular Sciences, Department of Medicine, Baylor College of Medicine, Houston, Texas, USA
,
Khatira Aboulfatova
1   Section of Cardiovascular Sciences, Department of Medicine, Baylor College of Medicine, Houston, Texas, USA
,
Renhao Li
2   Center for Membrane Biology, Department of Biochemistry and Molecular Biology, University of Texas Health Science Center at Houston, Houston, Texas, USA
,
Jing-fei Dong
1   Section of Cardiovascular Sciences, Department of Medicine, Baylor College of Medicine, Houston, Texas, USA
3   Tianjin Institute of Neurology, Tianjin Medical University, General Hospital, Tianjin, China
› Author Affiliations

Financial support: This work was supported by NIH grant HL71895 and HL82808.
Further Information

Publication History

Received: 14 July 2010

Accepted after major revision: 07 September 2010

Publication Date:
22 November 2017 (online)

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Summary

Upon stimulation, endothelial cells release von Willebrand factor (VWF) enriched in ultra-large (UL) forms that are rapidly cleaved by ADAMTS13. The zinc metalloprotease fits in the consensus for members of the ADAMTS family, but also contains two unique C-terminal CUB domains. There are five and two cysteine residues in the CUB-1 and CUB-2 domains, respectively, instead of four as deducted from the consensus. In this study, we investigated the role of cysteine residues in the CUB-1 domain in ADAMTS13 synthesis and activity. CUB-1 and cysteine mutations were expressed in mammalian cell lines and examined for synthesis, secretion, stability, and VWF-cleaving activity. When expressed as an isolated domain, CUB-1, but not CUB-2, covalently aggregated. Converting any of the four cysteines that fit in the CUB consensus (C1192, C1213, C1236 and C1254) reduced the secretion of the mutants to the conditioned medium, but not to extracellular matrix. The mutations also resulted in a moderate increase in proteolytic degradation and decrease in cleaving VWF under static, but not flowing conditions. In contrast, replacing C1275, which was found to be in the thiol form, with a serine residue prevented covalent aggregation of CUB-1, but had no effect on secretion and VWF-cleaving activity. C1275S was also markedly resistant to proteolytic degradation. The data illustrate the importance of consensus cysteines in the secretion and proteolytic activity of ADAMTS13. They also identify an ADAMTS-13 mutant that is resistant to proteolytic degradation, while maintaining a normal VWF-cleaving activity.