This "classical" PTH receptor is expressed in high levels in bone and kidney and regulates calcium ion homeostasis through activation of adenylate cyclase and phospholipase C.[5][6] In bone, it is expressed on the surface of osteoblasts.

When the receptor is activated through PTH binding, osteoblasts express RANKL (Receptor Activator of Nuclear Factor kB Ligand), which binds to RANK (Receptor Activator of Nuclear Factor kB) on osteoclasts.

This turns on osteoclasts to ultimately increase the resorption rate.

Defects in this receptor are known to be the cause of Jansen's metaphyseal chondrodysplasia (JMC) and chondrodysplasia Blomstrand type (BOCD) as well as enchondromatosis[7] and primary failure of tooth eruption.

[9] This article incorporates text from the United States National Library of Medicine, which is in the public domain.