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[Disorders Caused by Mutations in Calcium-Sensing Receptor and Related Diseases.]
1Disorders Caused by Mutations in Calcium-Sensing Receptor and Related Diseases.
Abstract:
Sensing of extracellular calcium(Ca2+)levels involves the Ca-sensing receptor(CaSR), its downstream signaling molecule Gα11, and the adaptor-related protein complex 2(AP2)that plays a role in clathrin-dependent endocytosis of CaSR. Inactivating mutations in CaSR cause familial hypocalciuric hypercalcemia type 1(FHH1)and neonatal severe hyperparathyroidism(NSHPT), while activating mutations lead to autosomal dominant hypocalcemia type 1(ADH1)and Bartter syndrome type Ⅴ. Recent studies have identified that inactivating mutations in Gα11 and σ-subunit of AP2(AP2σ)also cause FHH, and these conditions have been classified as FHH2 and FHH3, respectively. In addition, it has been revealed that activating mutations in Gα11 are responsible for ADH(ADH2). Calcimimetics and calcilytics may be beneficial in the treatment of these disorders.
Insights
The Ca-sensing receptor (CaSR) and its associated proteins, Gα11 and AP2, regulate calcium levels. Mutations in these genes cause genetic hypercalcemia and hypocalcemia disorders, suggesting potential therapeutic targets.
Area of Science:
- Biochemistry
- Genetics
- Endocrinology
Background:
- Extracellular calcium (Ca2+) homeostasis is primarily regulated by the Ca-sensing receptor (CaSR).
- The CaSR signaling pathway involves Gα11 and adaptor-related protein complex 2 (AP2), crucial for receptor endocytosis.
- Genetic variations in CaSR, Gα11, and AP2 are linked to calcium-related disorders.
Purpose of the Study:
- To elucidate the roles of CaSR, Gα11, and AP2 in calcium sensing.
- To understand the genetic basis of familial hypocalciuric hypercalcemia (FHH) and autosomal dominant hypocalcemia (ADH).
- To explore potential therapeutic strategies for calcium dysregulation disorders.
Main Methods:
- Review of existing literature on CaSR, Gα11, and AP2.
- Analysis of mutation data associated with FHH and ADH.
- Examination of the functional consequences of genetic variations.
Main Results:
- Inactivating CaSR mutations cause FHH1 and NSHPT.
- Activating CaSR mutations lead to ADH1 and Bartter syndrome type V.
- Inactivating Gα11 and AP2σ mutations result in FHH2 and FHH3, respectively.
- Activating Gα11 mutations are associated with ADH2.
Conclusions:
- Mutations in CaSR, Gα11, and AP2σ are key determinants of various genetic calcium disorders.
- These findings highlight the intricate roles of these proteins in calcium regulation.
- Calcimimetics and calcilytics show promise for treating these conditions.
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