G-protein coupled receptors in bone.
The skeleton is a dynamic structure that undergoes continuous remodeling, a prerequisite to meeting the constant loading demands placed upon it. This process is controlled by a multitude of systemic and local factors which interact with receptors presented on the surface of both osteoblasts and osteoclasts; the osteogenic and osteolytic cells of bone. The seven transmembrane G-protein coupled superfamily of receptors are amongst the most important expressed by bone cells. Many local and systemic factors, including prostaglandins and parathyroid hormone, initiate cellular processes via interaction with members of this receptor family. The diversity of signals and signaling cross talk generated by activated G-protein receptor complexes, facilitates a huge range of downstream responses essential in the remodeling of the skeleton. Indeed, agonist-activated signaling crosstalk provides a mechanism for integrating the activities of local and systemic factors, an essential requirement of focal remodeling. This review has focused on those currently known seven transmembrane receptors expressed by bone cells that couple to G-proteins, and describes the nature of receptor-G protein interaction and the resultant functional consequences of effector activation within bone cells.
Human Bone Cell Research Group, Department of Human Anatomy and Cell Biology, University of Liverpool, England, L69 3GE. wbb@liv.ac.uk
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Bowler
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Gallagher
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Bilbe
D000818:Animals; D001842:Bone and Bones / Q000502:physiology*; D020962:Heterotrimeric GTP-Binding Proteins / Q000502:physiology; D006801:Humans; D008024:Ligands; D010006:Osteoblasts / Q000502:physiology; D010010:Osteoclasts / Q000502:physiology; D010281:Parathyroid Hormone / Q000502:physiology; D044162:Parathyroid Hormone-Related Protein / Q000502:physiology; D044168:Receptor, Parathyroid Hormone, Type 1 / Q000378:metabolism; D011943:Receptors, Adrenergic, beta / Q000502:physiology; D011945:Receptors, Angiotensin / Q000502:physiology; D018003:Receptors, Calcitonin / Q000502:physiology; D044169:Receptors, Calcium-Sensing / Q000502:physiology; D043562:Receptors, G-Protein-Coupled / Q000502:physiology*; D011982:Receptors, Prostaglandin / Q000502:physiology; D018047:Receptors, Purinergic P1 / Q000502:physiology; D018048:Receptors, Purinergic P2 / Q000502:physiology
D008024:Ligands; D010281:Parathyroid Hormone; D044162:Parathyroid Hormone-Related Protein; D044168:Receptor, Parathyroid Hormone, Type 1; D011943:Receptors, Adrenergic, beta; D011945:Receptors, Angiotensin; D018003:Receptors, Calcitonin; D044169:Receptors, Calcium-Sensing; D043562:Receptors, G-Protein-Coupled; D011982:Receptors, Prostaglandin; D018047:Receptors, Purinergic P1; D018048:Receptors, Purinergic P2; D020962:Heterotrimeric GTP-Binding Proteins