Identification of a G-Protein Subunit-α11 Gain-of-Function Mutation, Val340Met, in a Family with Autosomal Dominant Hypocalcemia Type 2 (ADH2).



Piret, SE, Gorvin, CM, Pagnamenta, AT, Howles, SA, Cranston, T, Rust, N, Nesbit, MA, Glaser, B, Taylor, JC, Buchs, AE
et al (show 2 more authors) (2016) Identification of a G-Protein Subunit-α11 Gain-of-Function Mutation, Val340Met, in a Family with Autosomal Dominant Hypocalcemia Type 2 (ADH2). Journal of Bone and Mineral Research, 31 (6). pp. 1207-1214.

[img] Text
Piret_et_al-2016-Journal_of_Bone_and_Mineral_Research.pdf - Unspecified

Download (1MB)

Abstract

Autosomal dominant hypocalcemia (ADH) is characterized by hypocalcemia, inappropriately low serum parathyroid hormone concentrations and hypercalciuria. ADH is genetically heterogeneous with ADH type 1 (ADH1), the predominant form, being caused by germline gain-of-function mutations of the G-protein coupled calcium-sensing receptor (CaSR), and ADH2 caused by germline gain-of-function mutations of G-protein subunit α-11 (Gα11 ). To date Gα11 mutations causing ADH2 have been reported in only five probands. We investigated a multi-generational non-consanguineous family, from Iran, with ADH and keratoconus which are not known to be associated, for causative mutations by whole-exome sequencing in two individuals with hypoparathyroidism, of whom one also had keratoconus, followed by cosegregation analysis of variants. This identified a novel heterozygous germline Val340Met Gα11 mutation in both individuals, and this was also present in the other 2 relatives with hypocalcemia that were tested. Three-dimensional modeling revealed the Val340Met mutation to likely alter the conformation of the C-terminal α5 helix, which may affect G-protein coupled receptor binding and G-protein activation. In vitro functional expression of wild-type (Val340) and mutant (Met340) Gα11 proteins in HEK293 cells stably expressing the CaSR, demonstrated that the intracellular calcium responses following stimulation with extracellular calcium, of the mutant Met340 Gα11 led to a leftward shift of the concentration-response curve with a significantly (p

Item Type: Article
Uncontrolled Keywords: whole-exome sequencing, G-protein, calcium, hypoparathyroidism, keratoconus
Depositing User: Symplectic Admin
Date Deposited: 11 Feb 2016 10:40
Last Modified: 14 Mar 2024 21:21
DOI: 10.1002/jbmr.2797
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/2050820