l-Amino acid-sensing by calcium-sensing receptors: A molecular link between protein and calcium metabolism

Dietary protein intake has a major, positive influence on bone health including improved bone mineral density and reductions in fracture-incidence, however, the molecular origins of these effects are unclear. Herein we consider how the release of amino acids from dietary protein appears to provide molecular signals in the gastrointestinal tract as well as the portal and systemic blood and demonstrate how one, broad-spectrum, amino acid sensor, the extracellular calcium-sensing receptor, responds to these signals in endogenous tissues including the parathyroid, gut and kidney.