ChemInform Abstract: The Discovery of Novel Calcium Sensing Receptor Negative Allosteric Modulators.

Many membrane receptors are regulated by nutrients. However, how these nutrients control a single receptor remains unknown, even in the case of the well-studied calcium-sensing receptor CaSR, which is regulated by multiple factors, including ions and amino acids. Here, we developed an innovative cell-free Förster resonance energy transfer (FRET)-based conformational CaSR biosensor to clarify the main conformational changes associated with activation. By allowing a perfect control of ambient nutrients, this assay revealed that Ca2+alone fully stabilizes the active conformation, while amino acids behave as pure positive allosteric modulators. Based on the identification of Ca2+activation sites, we propose a molecular basis for how these different ligands cooperate to control CaSR activation. Our results provide important information on CaSR function and improve our understanding of the effects of genetic mutations responsible for human diseases. They also provide insights into how a receptor can integrate signals from various nutrients to better adapt to the cell response.

Download Full-text

Divergent effects of strontium and calcium-sensing receptor positive allosteric modulators (calcimimetics) on human osteoclast activity

British Journal of Pharmacology ◽

10.1111/bph.14344 ◽

2018 ◽

Vol 175 (21) ◽

pp. 4095-4108 ◽

Cited By ~ 11

Author(s):

Natalie A Diepenhorst ◽

Katie Leach ◽

Andrew N Keller ◽

Patricia Rueda ◽

Anna E Cook ◽

...

Keyword(s):

Allosteric Modulators ◽

Calcium Sensing Receptor ◽

Osteoclast Activity ◽

Calcium Sensing ◽

Human Osteoclast ◽

Positive Allosteric Modulators

Download Full-text

Loss-of-Function and Gain-of-Function Mutations of Calcium-Sensing Receptor: Functional Analysis and the Effect of Allosteric Modulators NPS R-568 and NPS 2143

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jc.2013-1974 ◽

2013 ◽

Vol 98 (10) ◽

pp. E1692-E1701 ◽

Cited By ~ 15

Author(s):

Akie Nakamura ◽

Tomoyuki Hotsubo ◽

Keiji Kobayashi ◽

Hiroshi Mochizuki ◽

Katsura Ishizu ◽

...

Keyword(s):

Cell Surface ◽

Surface Expression ◽

Cell Surface Expression ◽

Allosteric Modulators ◽

Familial Hypocalciuric Hypercalcemia ◽

Calcium Sensing Receptor ◽

Activating Mutations ◽

Casr Gene ◽

Calcium Sensing ◽

Inactivating Mutations

Abstract Objective: Activating mutations in the calcium-sensing receptor (CASR) gene cause autosomal dominant hypoparathyroidism, and heterozygous inactivating CASR mutations cause familial hypocalciuric hypercalcemia. Recently, there has been a focus on the use of allosteric modulators to restore the functional activity of mutant CASRs. In this study, the effect of allosteric modulators NPS R-568 and NPS 2143 on CASR mutants was studied in vitro. Methods: DNA sequence analysis of the CASR gene was undertaken in autosomal dominant hypoparathyroidism and familial hypocalciuric hypercalcemia Japanese patients, and the functional consequences for the Gi-MAPK pathway and cell surface expression of CASR were determined. Furthermore, we studied the effect of NPS R-568 and NPS 2143 on the signal transduction activity and cell surface expression of each mutant CASR. Results: We identified 3 activating mutations (S122C, P569H, and I839T) and 2 inactivating mutations (A110T and R172G) in patients. The activating and inactivating mutations caused leftward and rightward shifts, respectively, in the dose-response curves of the signaling pathway. NPS R-568 rescued the signal transduction capacity of 2 inactivating mutants without increasing cell surface expression levels. NPS 2143 suppressed the enhanced activity of the activating mutants without altering cell surface expression levels, although A843E, which is a constitutively active mutant, was suppressed to a lesser degree. Conclusions: We have identified 4 novel mutations of CASR. Moreover, our results indicate that allosteric modulators can restore the activity of the loss- and gain-of-function mutant CASRs, identified in this study.

Download Full-text

Faculty Opinions recommendation of Loss-of-function and gain-of-function mutations of calcium-sensing receptor: functional analysis and the effect of allosteric modulators NPS R-568 and NPS 2143.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.718083228.793523733 ◽

2016 ◽

Author(s):

Silvana Curci ◽

Matilde Colella ◽

Andrea Gerbino

Keyword(s):

Functional Analysis ◽

Allosteric Modulators ◽

Loss Of Function ◽

Calcium Sensing Receptor ◽

Gain Of Function ◽

Calcium Sensing

Download Full-text

Discovery of a class of calcium sensing receptor positive allosteric modulators; 1-(benzothiazol-2-yl)-1-phenylethanols

Bioorganic & Medicinal Chemistry Letters ◽

10.1016/j.bmcl.2010.07.077 ◽

2010 ◽

Vol 20 (19) ◽

pp. 5918-5921 ◽

Cited By ~ 6

Author(s):

Magnus Gustafsson ◽

Jacob Jensen ◽

Sine M. Bertozzi ◽

Erika A. Currier ◽

Jian-Nong Ma ◽

...

Keyword(s):

Allosteric Modulators ◽

Calcium Sensing Receptor ◽

Calcium Sensing ◽

Positive Allosteric Modulators

Download Full-text

Impact of Clinically Relevant Mutations on the Pharmacoregulation and Signaling Bias of the Calcium-Sensing Receptor by Positive and Negative Allosteric Modulators

Endocrinology ◽

10.1210/en.2012-1887 ◽

2013 ◽

Vol 154 (3) ◽

pp. 1105-1116 ◽

Cited By ~ 54

Author(s):

Katie Leach ◽

Adriel Wen ◽

Anna E. Cook ◽

Patrick M. Sexton ◽

Arthur D. Conigrave ◽

...

Keyword(s):

Cell Surface ◽

Intracellular Signaling ◽

Surface Expression ◽

Cell Surface Expression ◽

Allosteric Modulators ◽

Loss Of Function ◽

Functional Impairments ◽

Calcium Sensing Receptor ◽

Calcium Sensing ◽

The Impact

Abstract Cinacalcet is predominantly used to treat secondary hyperparathyroidism due to end-stage renal failure, but, more recently, its potential clinical efficacy in treating patients with loss-of-function mutations in the calcium-sensing receptor (CaSR) has been recognized. Many clinically relevant CaSR mutations are located in the heptahelical membrane spanning and extracellular loop regions of the receptor, where allosteric modulators are predicted to bind. The aim of the present study was to investigate the impact of such mutations on the pharmacoregulation of the CaSR by the positive and negative allosteric modulators, cinacalcet and NPS-2143, respectively. Both cinacalcet and NPS-2143 effectively rescued mutants whose cell surface expression was substantially impaired, suggesting that both classes of drug can stabilize a receptor conformation that is trafficked more effectively to the cell surface. In addition, functional impairments in almost all mutant CaSRs were rescued by either cinacalcet or NPS-2143 via restoration of intracellular signaling. There was a significantly greater ability of both compounds to modulate agonist-stimulated intracellular Ca2+ mobilization than ERK1/2 phosphorylation, indicating that the allosteric modulators engender bias in agonist-stimulated CaSR signaling to different pathways. Three mutations (G670R, P748R, and L773R) altered the binding affinity of allosteric modulators to the CaSR, and 3 mutations (V817I, L773R, and E767K) altered the cooperativity between the allosteric modulator and Ca2+o. These findings have important implications for the treatment of diseases associated with CaSR mutations using allosteric CaSR modulators and for analyzing the effects of mutations on the function and pharmacoregulation of the CaSR.

Download Full-text

Investigating the molecular mechanism of positive and negative allosteric modulators in the calcium-sensing receptor dimer

Scientific Reports ◽

10.1038/srep46355 ◽

2017 ◽

Vol 7 (1) ◽

Cited By ~ 11

Author(s):

Stine Engesgaard Jacobsen ◽

Ulrik Gether ◽

Hans Bräuner-Osborne

Keyword(s):

Molecular Mechanism ◽

Allosteric Modulators ◽

Calcium Sensing Receptor ◽

Calcium Sensing ◽

Receptor Dimer

Download Full-text

Development of AC265347‐Inspired Calcium‐sensing Receptor Ago‐Positive Allosteric Modulators

ChemMedChem ◽

10.1002/cmdc.202100368 ◽

2021 ◽

Author(s):

Le Vi Dinh ◽

Aaron DeBono ◽

Andrew Keller ◽

Tracy Josephs ◽

Karen Gregory ◽

...

Keyword(s):

Allosteric Modulators ◽

Calcium Sensing Receptor ◽

Calcium Sensing ◽

Positive Allosteric Modulators

Download Full-text

Calcium-sensing receptor in GtoPdb v.2021.3

IUPHAR/BPS Guide to Pharmacology CITE ◽

10.2218/gtopdb/f12/2021.3 ◽

2021 ◽

Vol 2021 (3) ◽

Author(s):

Daniel Bikle ◽

Hans Bräuner-Osborne ◽

Edward M. Brown ◽

Wenhan Chang ◽

Arthur Conigrave ◽

...

Keyword(s):

Amino Acids ◽

Ionic Strength ◽

Receptor Activation ◽

Extracellular Ph ◽

Allosteric Modulators ◽

Calcium Sensing Receptor ◽

Calcium Sensing ◽

Trivalent Cations ◽

Amino Acid Binding ◽

Peptide Analogues

The calcium-sensing receptor (CaS, provisional nomenclature as recommended by NC-IUPHAR [47] and subsequently updated [77]) responds to multiple endogenous ligands, including extracellular calcium and other divalent/trivalent cations, polyamines and polycationic peptides, L-amino acids (particularly L-Trp and L-Phe), glutathione and various peptide analogues, ionic strength and extracellular pH (reviewed in [78]). While divalent/trivalent cations, polyamines and polycations are CaS receptor agonists [14, 110], L-amino acids, glutamyl peptides, ionic strength and pH are allosteric modulators of agonist function [36, 47, 61, 108, 109]. Indeed, L-amino acids have been identified as "co-agonists", with both concomitant calcium and L-amino acid binding required for full receptor activation [148, 54]. The sensitivity of the CaS receptor to primary agonists is increased by elevated extracellular pH [18] or decreased extracellular ionic strength [109]. This receptor bears no sequence or structural relation to the plant calcium receptor, also called CaS.

Download Full-text