Parathyroid hormone synthesis, secretion and action - Tupaia chinensis (Chinese tree shrew)
Description
Parathyroid hormone (PTH) is a key regulator of calcium and phosphorus homeostasis. The principal regulators of PTH secretion are extracellular ionized calcium (Ca2+) and 1,25-dihydroxyvitamin D (1,25(OH)2D3). Under conditions of dietary Ca restriction, a decrement in serum Ca concentration induces release of PTH from the parathyroid gland. PTH acts on bone and kidney to stimulate bone turnover, increase the circulating levels of 1,25(OH)2D3 and calcium and inhibit the reabsorption of phosphate from the glomerular filtrate. This hormone exerts its actions via binding to the PTH/PTH-related peptide receptor (PTH1R). PTH1R primarily activates two sub-types of heterotrimeric Gproteins: Gs and Gq , which in turn regulate the activity of adenylyl cyclases and phospholipase C (PLC) that control the flow of cAMP/PKA and IP/PKC signaling cascades, respectively.
Wang B, Means CK, Yang Y, Mamonova T, Bisello A, Altschuler DL, Scott JD, Friedman PA
Title
Ezrin-anchored protein kinase A coordinates phosphorylation-dependent disassembly of a NHERF1 ternary complex to regulate hormone-sensitive phosphate transport.
Parathyroid hormone stimulates receptor activator of NFkappa B ligand and inhibits osteoprotegerin expression via protein kinase A activation of cAMP-response element-binding protein.
Parathyroid hormone induces c-fos promoter activity in osteoblastic cells through phosphorylated cAMP response element (CRE)-binding protein binding to the major CRE.
AP-1 and Cbfa/runt physically interact and regulate parathyroid hormone-dependent MMP13 expression in osteoblasts through a new osteoblast-specific element 2/AP-1 composite element.
Transactivation of the epidermal growth factor receptor mediates parathyroid hormone and prostaglandin F2 alpha-stimulated mitogen-activated protein kinase activation in cultured transgenic murine osteoblasts.
