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AVPR2 variants and V2 vasopressin receptor function in nephrogenic diabetes insipidus.
Kidney Int. 1998 Dec; 54(6):1909-22.KI

Abstract

BACKGROUND

The AVPR2 gene encodes the type 2 vasopressin receptor, a member of the vasopressin/oxytocin receptor subfamily of G protein-coupled receptors. Disruption of AVPR2 causes X-linked congenital nephrogenic diabetes insipidus (NDI), yet the functional significance of most gene sequence variations found in association with NDI has not been proven. The large number of naturally occurring AVPR2 mutations constitutes a model system for studying the structure-function relationship of G protein-coupled receptors. This analysis can be aided by examining amino acid sequence variation and conservation among evolutionarily disparate members of the subfamily.

METHODS

Twenty-five new NDI patients were evaluated by DNA sequencing for mutations in AVPR2. Receptors encoded by eighteen NDI alleles were tested for physiologic signaling activity in response to varying concentrations of arginine vasopressin (AVP) in a sensitive cell culture assay. Seventeen amino acid sequences from the vasopressin/oxytocin receptor subfamily were aligned and conserved residues were identified and correlated with the locations of NDI associated variations.

RESULTS

Twenty-four variant alleles were found among the 25 new patients. Thirteen had no prior family history of expressed NDI. All 18 of the NDI-associated AVPR2 alleles tested for function demonstrated diminished response to stimulation with AVP. Twelve failed to respond at all, whereas six signaled only at high AVP concentrations. Evolutionarily conserved residues clustered in the transmembrane domains and in the first and second extracellular loops, and NDI-associated missense mutations appeared mostly in the conserved domains.

CONCLUSIONS

Sporadic cases are frequent and they usually represent the X-linked rather than the autosomal form of NDI. Genetic and functional testing can confirm this in individual cases. Mutations in this study affecting ligand binding domains tend to retain partial signaling in vitro, whereas those that introduce a charged residue in a transmembrane domain are inactive. The minimal partial signaling observed in cultured cells is unlikely to correlate with clinically significant urine concentrating ability. Other AVPR2 mutations with milder effects on receptor function probably exist, but may not be expressed clinically as typical NDI.

Authors+Show Affiliations

Department of Molecular and Medical Genetics, Oregon Health Sciences University, Portland, USA. wildinr@ohsu.eduNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

9853256

Citation

Wildin, R S., et al. "AVPR2 Variants and V2 Vasopressin Receptor Function in Nephrogenic Diabetes Insipidus." Kidney International, vol. 54, no. 6, 1998, pp. 1909-22.
Wildin RS, Cogdell DE, Valadez V. AVPR2 variants and V2 vasopressin receptor function in nephrogenic diabetes insipidus. Kidney Int. 1998;54(6):1909-22.
Wildin, R. S., Cogdell, D. E., & Valadez, V. (1998). AVPR2 variants and V2 vasopressin receptor function in nephrogenic diabetes insipidus. Kidney International, 54(6), 1909-22.
Wildin RS, Cogdell DE, Valadez V. AVPR2 Variants and V2 Vasopressin Receptor Function in Nephrogenic Diabetes Insipidus. Kidney Int. 1998;54(6):1909-22. PubMed PMID: 9853256.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - AVPR2 variants and V2 vasopressin receptor function in nephrogenic diabetes insipidus. AU - Wildin,R S, AU - Cogdell,D E, AU - Valadez,V, PY - 1998/12/16/pubmed PY - 1998/12/16/medline PY - 1998/12/16/entrez SP - 1909 EP - 22 JF - Kidney international JO - Kidney Int VL - 54 IS - 6 N2 - BACKGROUND: The AVPR2 gene encodes the type 2 vasopressin receptor, a member of the vasopressin/oxytocin receptor subfamily of G protein-coupled receptors. Disruption of AVPR2 causes X-linked congenital nephrogenic diabetes insipidus (NDI), yet the functional significance of most gene sequence variations found in association with NDI has not been proven. The large number of naturally occurring AVPR2 mutations constitutes a model system for studying the structure-function relationship of G protein-coupled receptors. This analysis can be aided by examining amino acid sequence variation and conservation among evolutionarily disparate members of the subfamily. METHODS: Twenty-five new NDI patients were evaluated by DNA sequencing for mutations in AVPR2. Receptors encoded by eighteen NDI alleles were tested for physiologic signaling activity in response to varying concentrations of arginine vasopressin (AVP) in a sensitive cell culture assay. Seventeen amino acid sequences from the vasopressin/oxytocin receptor subfamily were aligned and conserved residues were identified and correlated with the locations of NDI associated variations. RESULTS: Twenty-four variant alleles were found among the 25 new patients. Thirteen had no prior family history of expressed NDI. All 18 of the NDI-associated AVPR2 alleles tested for function demonstrated diminished response to stimulation with AVP. Twelve failed to respond at all, whereas six signaled only at high AVP concentrations. Evolutionarily conserved residues clustered in the transmembrane domains and in the first and second extracellular loops, and NDI-associated missense mutations appeared mostly in the conserved domains. CONCLUSIONS: Sporadic cases are frequent and they usually represent the X-linked rather than the autosomal form of NDI. Genetic and functional testing can confirm this in individual cases. Mutations in this study affecting ligand binding domains tend to retain partial signaling in vitro, whereas those that introduce a charged residue in a transmembrane domain are inactive. The minimal partial signaling observed in cultured cells is unlikely to correlate with clinically significant urine concentrating ability. Other AVPR2 mutations with milder effects on receptor function probably exist, but may not be expressed clinically as typical NDI. SN - 0085-2538 UR - https://www.unboundmedicine.com/medline/citation/9853256/AVPR2_variants_and_V2_vasopressin_receptor_function_in_nephrogenic_diabetes_insipidus_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0085-2538(15)30828-0 DB - PRIME DP - Unbound Medicine ER -