Functional rescue of the nephrogenic diabetes insipidus-causing vasopressin V2 receptor mutants G185C and R202C by a second site suppressor mutation

Item Type:	Article
Title:	Functional rescue of the nephrogenic diabetes insipidus-causing vasopressin V2 receptor mutants G185C and R202C by a second site suppressor mutation
Creators Name:	Schuelein, R. and Zuehlke, K. and Krause, G. and Rosenthal, W.
Abstract:	Mutations in the gene of the G protein-coupled vasopressin V2 receptor (V2 receptor) cause X-linked nephrogenic diabetes insipidus (NDI). Most of the missense mutations on the extracellular face of the receptor introduce additional cysteine residues. Several groups have proposed that these residues might disrupt the conserved disulfide bond of the V2 receptor. To test this hypothesis, we first calculated a structure model of the extracellular receptor domains. The model suggests that the additional cysteine residues may form a second disulfide bond with the free, nonconserved extracellular cysteine residue Cys-195 rather than impairing the conserved bond. To address this question experimentally, we used the NDI-causing mutant receptors G185C and R202C. Their Cys-195 residues were replaced by alanine to eliminate the hypothetical second disulfide bonds. This second site mutation led to functional rescue of both NDI-causing mutant receptors, strongly suggesting that the second disulfide bonds are indeed formed. Furthermore we show that residue Cys-195, which is sensitive to "additional cysteine" mutations, is not conserved among the V2 receptors of other species and that the presence of an uneven number of extracellular cysteine residues, as in the human V2 receptor, is rare among class I G protein-coupled receptors.
Keywords:	Amino Acid Sequence, Nephrogenic Diabetes Insipidus, Structural Models, Molecular Sequence Data, Molecular Weight, Mutation, Vasopressin Receptors
Source:	Journal of Biological Chemistry
ISSN:	0021-9258
Publisher:	American Society for Biochemistry and Molecular Biology
Volume:	276
Number:	11
Page Range:	8384-8392
Date:	16 March 2001
Official Publication:	https://doi.org/10.1074/jbc.M007045200
PubMed:	View item in PubMed

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