The parathyroid hormone 2 (PTH2) receptor.
The human PTH2 receptor binds and is activated at high potency by PTH and by the recently discovered peptide tuberoinfundibular peptide of 39 residues (TIP39). Rat and zebrafish PTH2 receptors are more weakly activated by PTH, suggesting that TIP39 may be the natural ligand for the PTH2 receptor. Unlike the PTH1 receptor, the PTH2 receptor interacts extremely weakly with parathyroid hormone-related peptide (PTHrP). The PTH2 receptor is strongly coupled to stimulation of cAMP accumulation, and more weakly, in a cell-specific manner to increases in intracellular calcium concentration. A variety of evidence supports the general model of receptor amino terminal sequences binding ligand carboxyl terminal sequences with high affinity, and ligand amino terminal sequences activating the receptor through interaction with the "juxtamembrane" portion of the receptor. The receptor is present at greatest levels in the nervous system. It is expressed in scattered cells in the cerebral cortex and basal ganglia and at relatively high abundance in the septum, midline thalamic nuclei, several hypothalamic nuclei, and the dorsal horn of the spinal cord. Peripherally, expression in pancreatic islet somatostatin cells is most dramatic. Functional hypotheses based on the receptor's distribution are being tested. Recent data support involvement in hypothalamic releasing-factor secretion and pain.
Usdin
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Laboratory of Genetics, National Institute of Mental Health, Building 36/Room 3D06, 36 Convent Drive, Bethesda, Maryland 20892-4094, USA. usdin@codon.nih.gov
Bonner
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Hoare
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D000595:Amino Acid Sequence; D000818:Animals; D002352:Carrier Proteins / Q000235:genetics; D019204:GTP-Binding Proteins / Q000235:genetics; D006801:Humans; D008969:Molecular Sequence Data; D009687:Nuclear Proteins; D009928:Organ Specificity; D010281:Parathyroid Hormone / Q000235:genetics; D000072260:RNA Splicing Factors; D051381:Rats; D044183:Receptor, Parathyroid Hormone, Type 2; D018016:Receptors, Parathyroid Hormone / Q000819:agonists / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D015398:Signal Transduction / Q000502:physiology; D033921:Vesicular Transport Proteins
D002352:Carrier Proteins; D009687:Nuclear Proteins; D010281:Parathyroid Hormone; D000072260:RNA Splicing Factors; D044183:Receptor, Parathyroid Hormone, Type 2; D018016:Receptors, Parathyroid Hormone; C485860:TFIP11 protein, human; D033921:Vesicular Transport Proteins; D019204:GTP-Binding Proteins