Physiological significance of L-amino acid sensing by extracellular Ca(2+)-sensing receptors.
The calcium-sensing receptor is a multimodal, multimetabolic sensor that mediates the feedback-dependent control of whole body calcium metabolism. Remarkably, in addition to its role in Ca(2+)(o) (extracellular Ca(2+)) sensing, the CaR (Ca(2+)-sensing receptor) also responds to L-amino acids. L-amino acids appear to activate, predominantly, a signalling pathway coupled with intracellular Ca(2+) mobilization, require a threshold concentration of Ca(2+)(o) for efficacy and sensitize the receptor to activation by Ca(2+)(o). Here, we review the evidence that the CaR, like other closely related members of the class 3 GPCR (G-protein-coupled receptor) family including GPRC6A, is a broad-spectrum amino acid-sensing receptor, consider the nature of the signalling response to amino acids and discuss its physiological significance.
Conigrave
A D
AD
School of Molecular and Microbial Biosciences, G08, University of Sydney, Sydney, NSW 2006, Australia. a.conigrave@mmb.usyd.edu.au
Mun
H-C
HC
Brennan
S C
SC
D000596:Amino Acids / Q000502:physiology*; D044169:Receptors, Calcium-Sensing / Q000502:physiology*; D015398:Signal Transduction
D000596:Amino Acids; D044169:Receptors, Calcium-Sensing