Calcium-sensing receptor residues with loss- and gain-of-function mutations are located in regions of conformational change and cause signalling bias
The calcium-sensing receptor (CaSR) is a homodimeric G-protein-coupled receptor that signals via intracellular calcium (Ca2+i) mobilisation and phosphorylation of extracellular signal-regulated kinase 1/2 (ERK) to regulate extracellular calcium (Ca2+e) homeostasis. The central importance of the CaSR...
| Main Authors: | , , , , , , , , |
|---|---|
| Format: | Journal article |
| Language: | English |
| Published: |
Oxford University Press
2018
|
| _version_ | 1797070258199068672 |
|---|---|
| author | Gorvin, C Frost, M Malinauskas, T Cranston, T Boon, H Siebold, C Jones, E Hannan, F Thakker, R |
| author_facet | Gorvin, C Frost, M Malinauskas, T Cranston, T Boon, H Siebold, C Jones, E Hannan, F Thakker, R |
| author_sort | Gorvin, C |
| collection | OXFORD |
| description | The calcium-sensing receptor (CaSR) is a homodimeric G-protein-coupled receptor that signals via intracellular calcium (Ca2+i) mobilisation and phosphorylation of extracellular signal-regulated kinase 1/2 (ERK) to regulate extracellular calcium (Ca2+e) homeostasis. The central importance of the CaSR in Ca2+e homeostasis has been demonstrated by the identification of loss- or gain-of-function CaSR mutations that lead to familial hypocalciuric hypercalcaemia (FHH) or autosomal dominant hypocalcaemia (ADH), respectively. However, the mechanisms determining whether the CaSR signals via Ca2+i or ERK have not been established, and we hypothesised that some CaSR residues, which are the site of both loss- and gain-of-function mutations, may act as molecular switches to direct signalling through these pathways. An analysis of CaSR mutations identified in >300 hypercalcaemic and hypocalcaemic probands revealed five 'disease-switch' residues (Gln27, Asn178, Ser657, Ser820 and Thr828) that are affected by FHH and ADH mutations. Functional expression studies using HEK293 cells showed disease-switch residue mutations to commonly display signalling bias. For example, two FHH-associated mutations (p.Asn178Asp and p.Ser820Ala) impaired Ca2+i signalling without altering ERK phosphorylation. In contrast, an ADH-associated p.Ser657Cys mutation uncoupled signalling by leading to increased Ca2+i mobilization while decreasing ERK phosphorylation. Structural analysis of these five CaSR disease-switch residues together with four reported disease-switch residues revealed these residues to be located at conformationally active regions of the CaSR such as the extracellular dimer interface and transmembrane domain. Thus, our findings indicate that disease-switch residues are located at sites critical for CaSR activation and play a role in mediating signalling bias. |
| first_indexed | 2024-03-06T22:36:13Z |
| format | Journal article |
| id | oxford-uuid:59fed675-84c6-4173-811d-8456972eefc8 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T22:36:13Z |
| publishDate | 2018 |
| publisher | Oxford University Press |
| record_format | dspace |
| spelling | oxford-uuid:59fed675-84c6-4173-811d-8456972eefc82022-03-26T17:13:06ZCalcium-sensing receptor residues with loss- and gain-of-function mutations are located in regions of conformational change and cause signalling biasJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:59fed675-84c6-4173-811d-8456972eefc8EnglishSymplectic Elements at OxfordOxford University Press2018Gorvin, CFrost, MMalinauskas, TCranston, TBoon, HSiebold, CJones, EHannan, FThakker, RThe calcium-sensing receptor (CaSR) is a homodimeric G-protein-coupled receptor that signals via intracellular calcium (Ca2+i) mobilisation and phosphorylation of extracellular signal-regulated kinase 1/2 (ERK) to regulate extracellular calcium (Ca2+e) homeostasis. The central importance of the CaSR in Ca2+e homeostasis has been demonstrated by the identification of loss- or gain-of-function CaSR mutations that lead to familial hypocalciuric hypercalcaemia (FHH) or autosomal dominant hypocalcaemia (ADH), respectively. However, the mechanisms determining whether the CaSR signals via Ca2+i or ERK have not been established, and we hypothesised that some CaSR residues, which are the site of both loss- and gain-of-function mutations, may act as molecular switches to direct signalling through these pathways. An analysis of CaSR mutations identified in >300 hypercalcaemic and hypocalcaemic probands revealed five 'disease-switch' residues (Gln27, Asn178, Ser657, Ser820 and Thr828) that are affected by FHH and ADH mutations. Functional expression studies using HEK293 cells showed disease-switch residue mutations to commonly display signalling bias. For example, two FHH-associated mutations (p.Asn178Asp and p.Ser820Ala) impaired Ca2+i signalling without altering ERK phosphorylation. In contrast, an ADH-associated p.Ser657Cys mutation uncoupled signalling by leading to increased Ca2+i mobilization while decreasing ERK phosphorylation. Structural analysis of these five CaSR disease-switch residues together with four reported disease-switch residues revealed these residues to be located at conformationally active regions of the CaSR such as the extracellular dimer interface and transmembrane domain. Thus, our findings indicate that disease-switch residues are located at sites critical for CaSR activation and play a role in mediating signalling bias. |
| spellingShingle | Gorvin, C Frost, M Malinauskas, T Cranston, T Boon, H Siebold, C Jones, E Hannan, F Thakker, R Calcium-sensing receptor residues with loss- and gain-of-function mutations are located in regions of conformational change and cause signalling bias |
| title | Calcium-sensing receptor residues with loss- and gain-of-function mutations are located in regions of conformational change and cause signalling bias |
| title_full | Calcium-sensing receptor residues with loss- and gain-of-function mutations are located in regions of conformational change and cause signalling bias |
| title_fullStr | Calcium-sensing receptor residues with loss- and gain-of-function mutations are located in regions of conformational change and cause signalling bias |
| title_full_unstemmed | Calcium-sensing receptor residues with loss- and gain-of-function mutations are located in regions of conformational change and cause signalling bias |
| title_short | Calcium-sensing receptor residues with loss- and gain-of-function mutations are located in regions of conformational change and cause signalling bias |
| title_sort | calcium sensing receptor residues with loss and gain of function mutations are located in regions of conformational change and cause signalling bias |
| work_keys_str_mv | AT gorvinc calciumsensingreceptorresidueswithlossandgainoffunctionmutationsarelocatedinregionsofconformationalchangeandcausesignallingbias AT frostm calciumsensingreceptorresidueswithlossandgainoffunctionmutationsarelocatedinregionsofconformationalchangeandcausesignallingbias AT malinauskast calciumsensingreceptorresidueswithlossandgainoffunctionmutationsarelocatedinregionsofconformationalchangeandcausesignallingbias AT cranstont calciumsensingreceptorresidueswithlossandgainoffunctionmutationsarelocatedinregionsofconformationalchangeandcausesignallingbias AT boonh calciumsensingreceptorresidueswithlossandgainoffunctionmutationsarelocatedinregionsofconformationalchangeandcausesignallingbias AT sieboldc calciumsensingreceptorresidueswithlossandgainoffunctionmutationsarelocatedinregionsofconformationalchangeandcausesignallingbias AT jonese calciumsensingreceptorresidueswithlossandgainoffunctionmutationsarelocatedinregionsofconformationalchangeandcausesignallingbias AT hannanf calciumsensingreceptorresidueswithlossandgainoffunctionmutationsarelocatedinregionsofconformationalchangeandcausesignallingbias AT thakkerr calciumsensingreceptorresidueswithlossandgainoffunctionmutationsarelocatedinregionsofconformationalchangeandcausesignallingbias |