Overview
- Peptide CFLQPDINIGKQE, corresponding to amino acid residues 125-137 of rat PTH2R (Accession P70555). Extracellular, N-terminus.
- Mouse hippocampus (1:60).
Multiplex staining of Parathyroid hormone 2 receptor and Vesicular glutamate transporter 2 in mouse hippocampusImmunohistochemical staining of mouse hippocampal CA3 region frozen sections using Anti-PTH2R (extracellular)-ATTO Fluor-488 Antibody (#APR-052-AG), (1:60) and Anti-VGLUT2-ATTO Fluor-594 Antibody (#AGC-036-AR), (1:60). A. PTH2 receptor staining (green). B. VGLUT2 staining (red) in same section. C. Merge of A and B suggests extensive localization of PTH2R on glutamatergic neurons.
PTH (parathyroid hormone) regulates Ca2+ and phosphate homeostasis through its action on specific receptors in kidney and bone. There are two known PTH receptors in humans, PTH receptor type 1 (PTH1 receptor) and PTH receptor type 2 (PTH2 receptor)1.
The PTH2 receptor is a member of a class B subfamily of G-protein-coupled receptors that includes the receptors for the glucagon-GHRH-VIP family of peptides (glucagon, GLP-I, GIP, GHRH, VIP, secretin, PACAP) and for calcitonin and CRF2. PTH2 receptor shares the same basic structure of the GPCR superfamily of proteins. A defining feature of the family B receptors is the relatively long extracellular N-terminal domain, which comprises about 150 amino acids and is important for ligand binding. The seven transmembrane domains are believed to be arranged in a circular or oval configuration, as seen in rhodopsin. The transmembrane domains are connected by three extracellular and three intracellular loops, and a C-terminal tail of about 130 amino acids extends intracellularly3.
Northern blots of human messenger RNA (mRNA) show that the PTH2 receptor is most highly expressed in the central nervous system, preferentially in the hypothalamic regions and is also detected in the pancreas, testis, placenta, and lung4.
Recent data support that PTH2 receptor is involved in hypothalamic releasing-factor secretion and pain5.
