Osteoblast calcium-sensing receptor has characteristics of ANF/7TM receptors

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

There is evidence for a functionally important extracellular calcium-sensing receptor in osteoblasts, but there is disagreement regarding its identity. Candidates are CASR and a putative novel calcium-sensing receptor, called Ob.CASR. To further characterize Ob.CASR and to distinguish it from CASR, we examined the extracellular cation-sensing response in MC3T3-E1 osteoblasts and in osteoblasts derived from CASR null mice. We found that extracellular cations activate ERK and serum response element (SRE)-luciferase reporter activity in osteoblasts lacking CASR. Amino acids, but not the calcimimetic NPS-R568, an allosteric modulator of CASR, also stimulate Ob.CASR-dependent SRE-luciferase activation in MC3T3-E1 osteoblasts. In addition, we found that the dominant negative Gαq(305-359) construct inhibited cation-stimulated ERK activation, consistent with Ob.CASR coupling to Gαq-dependent pathways. Ob.CASR is also a target for classical GPCR desensitization mechanisms, since β-arrestins, which bind to and uncouple GRK phosphorylated GPCRs, attenuated cation-stimulated SRE-luciferase activity in CASR deficient osteoblasts. Finally, we found that Ob.CASR and CASR couple to SRE through distinct signaling pathways. Ob.CASR does not activate RhoA and C3 toxin fails to block Ob.CASR-induced SRE-luciferase activity. Mutational analysis of the serum response factor (SRF) and ternary complex factor (TCF) elements in SRE demonstrates that Ob.CASR predominantly activates TCF-dependent mechanisms, whereas CASR activates SRE-luciferase mainly through a RhoA and SRF-dependent mechanism. The ability of Ob.CASR to sense cations and amino acids and function like a G-protein coupled receptor suggests that it may belong to the family of receptors characterized by an evolutionarily conserved amino acid sensing motif (ANF) linked to an intramembranous 7 transmembrane loop region (7TM).

Original languageEnglish (US)
Pages (from-to)1081-1092
Number of pages12
JournalJournal of Cellular Biochemistry
Volume95
Issue number6
DOIs
StatePublished - Aug 15 2005
Externally publishedYes

Fingerprint

Serum Response Element
Atrial Natriuretic Factor Receptors
Calcium-Sensing Receptors
Osteoblasts
Luciferases
Cations
Ternary Complex Factors
Serum Response Factor
Amino Acids
N-(2-chlorophenylpropyl)-1-(3-methoxyphenyl)ethylamine
Chemical activation
Arrestins
Amino Acid Motifs
Atrial Natriuretic Factor
G-Protein-Coupled Receptors
Modulators

All Science Journal Classification (ASJC) codes

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Cite this

Osteoblast calcium-sensing receptor has characteristics of ANF/7TM receptors. / Pi, Min; Quarles, Leigh.

In: Journal of Cellular Biochemistry, Vol. 95, No. 6, 15.08.2005, p. 1081-1092.

Research output: Contribution to journalArticle

@article{91f6d47b06ff496f87914834dc4178aa,
title = "Osteoblast calcium-sensing receptor has characteristics of ANF/7TM receptors",
abstract = "There is evidence for a functionally important extracellular calcium-sensing receptor in osteoblasts, but there is disagreement regarding its identity. Candidates are CASR and a putative novel calcium-sensing receptor, called Ob.CASR. To further characterize Ob.CASR and to distinguish it from CASR, we examined the extracellular cation-sensing response in MC3T3-E1 osteoblasts and in osteoblasts derived from CASR null mice. We found that extracellular cations activate ERK and serum response element (SRE)-luciferase reporter activity in osteoblasts lacking CASR. Amino acids, but not the calcimimetic NPS-R568, an allosteric modulator of CASR, also stimulate Ob.CASR-dependent SRE-luciferase activation in MC3T3-E1 osteoblasts. In addition, we found that the dominant negative Gαq(305-359) construct inhibited cation-stimulated ERK activation, consistent with Ob.CASR coupling to Gαq-dependent pathways. Ob.CASR is also a target for classical GPCR desensitization mechanisms, since β-arrestins, which bind to and uncouple GRK phosphorylated GPCRs, attenuated cation-stimulated SRE-luciferase activity in CASR deficient osteoblasts. Finally, we found that Ob.CASR and CASR couple to SRE through distinct signaling pathways. Ob.CASR does not activate RhoA and C3 toxin fails to block Ob.CASR-induced SRE-luciferase activity. Mutational analysis of the serum response factor (SRF) and ternary complex factor (TCF) elements in SRE demonstrates that Ob.CASR predominantly activates TCF-dependent mechanisms, whereas CASR activates SRE-luciferase mainly through a RhoA and SRF-dependent mechanism. The ability of Ob.CASR to sense cations and amino acids and function like a G-protein coupled receptor suggests that it may belong to the family of receptors characterized by an evolutionarily conserved amino acid sensing motif (ANF) linked to an intramembranous 7 transmembrane loop region (7TM).",
author = "Min Pi and Leigh Quarles",
year = "2005",
month = "8",
day = "15",
doi = "10.1002/jcb.20500",
language = "English (US)",
volume = "95",
pages = "1081--1092",
journal = "Journal of Cellular Biochemistry",
issn = "0730-2312",
publisher = "Wiley-Liss Inc.",
number = "6",

}

TY - JOUR

T1 - Osteoblast calcium-sensing receptor has characteristics of ANF/7TM receptors

AU - Pi, Min

AU - Quarles, Leigh

PY - 2005/8/15

Y1 - 2005/8/15

N2 - There is evidence for a functionally important extracellular calcium-sensing receptor in osteoblasts, but there is disagreement regarding its identity. Candidates are CASR and a putative novel calcium-sensing receptor, called Ob.CASR. To further characterize Ob.CASR and to distinguish it from CASR, we examined the extracellular cation-sensing response in MC3T3-E1 osteoblasts and in osteoblasts derived from CASR null mice. We found that extracellular cations activate ERK and serum response element (SRE)-luciferase reporter activity in osteoblasts lacking CASR. Amino acids, but not the calcimimetic NPS-R568, an allosteric modulator of CASR, also stimulate Ob.CASR-dependent SRE-luciferase activation in MC3T3-E1 osteoblasts. In addition, we found that the dominant negative Gαq(305-359) construct inhibited cation-stimulated ERK activation, consistent with Ob.CASR coupling to Gαq-dependent pathways. Ob.CASR is also a target for classical GPCR desensitization mechanisms, since β-arrestins, which bind to and uncouple GRK phosphorylated GPCRs, attenuated cation-stimulated SRE-luciferase activity in CASR deficient osteoblasts. Finally, we found that Ob.CASR and CASR couple to SRE through distinct signaling pathways. Ob.CASR does not activate RhoA and C3 toxin fails to block Ob.CASR-induced SRE-luciferase activity. Mutational analysis of the serum response factor (SRF) and ternary complex factor (TCF) elements in SRE demonstrates that Ob.CASR predominantly activates TCF-dependent mechanisms, whereas CASR activates SRE-luciferase mainly through a RhoA and SRF-dependent mechanism. The ability of Ob.CASR to sense cations and amino acids and function like a G-protein coupled receptor suggests that it may belong to the family of receptors characterized by an evolutionarily conserved amino acid sensing motif (ANF) linked to an intramembranous 7 transmembrane loop region (7TM).

AB - There is evidence for a functionally important extracellular calcium-sensing receptor in osteoblasts, but there is disagreement regarding its identity. Candidates are CASR and a putative novel calcium-sensing receptor, called Ob.CASR. To further characterize Ob.CASR and to distinguish it from CASR, we examined the extracellular cation-sensing response in MC3T3-E1 osteoblasts and in osteoblasts derived from CASR null mice. We found that extracellular cations activate ERK and serum response element (SRE)-luciferase reporter activity in osteoblasts lacking CASR. Amino acids, but not the calcimimetic NPS-R568, an allosteric modulator of CASR, also stimulate Ob.CASR-dependent SRE-luciferase activation in MC3T3-E1 osteoblasts. In addition, we found that the dominant negative Gαq(305-359) construct inhibited cation-stimulated ERK activation, consistent with Ob.CASR coupling to Gαq-dependent pathways. Ob.CASR is also a target for classical GPCR desensitization mechanisms, since β-arrestins, which bind to and uncouple GRK phosphorylated GPCRs, attenuated cation-stimulated SRE-luciferase activity in CASR deficient osteoblasts. Finally, we found that Ob.CASR and CASR couple to SRE through distinct signaling pathways. Ob.CASR does not activate RhoA and C3 toxin fails to block Ob.CASR-induced SRE-luciferase activity. Mutational analysis of the serum response factor (SRF) and ternary complex factor (TCF) elements in SRE demonstrates that Ob.CASR predominantly activates TCF-dependent mechanisms, whereas CASR activates SRE-luciferase mainly through a RhoA and SRF-dependent mechanism. The ability of Ob.CASR to sense cations and amino acids and function like a G-protein coupled receptor suggests that it may belong to the family of receptors characterized by an evolutionarily conserved amino acid sensing motif (ANF) linked to an intramembranous 7 transmembrane loop region (7TM).

UR - http://www.scopus.com/inward/record.url?scp=26444450720&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=26444450720&partnerID=8YFLogxK

U2 - 10.1002/jcb.20500

DO - 10.1002/jcb.20500

M3 - Article

VL - 95

SP - 1081

EP - 1092

JO - Journal of Cellular Biochemistry

JF - Journal of Cellular Biochemistry

SN - 0730-2312

IS - 6

ER -