extracellular Ca+2-sensing receptor; CaSR; parathyroid cell Ca+2-sensing receptor; PCaR1 (CASR, GPRC2A, PCAR1)

Function

• senses changes in the extracellular concentration of Ca+2
• activity is mediated by a G-protein that activates a phosphatidylinositol-Ca+2 second messenger system
• interacts with VCP & RNF19A
• ubiquitinated by RNF19A; which induces proteasomal degradation

Structure

• N-glycosylated
• belongs to the G-protein coupled receptor 3 family
• the extracellular domain of the Ca+2 receptor (605 aa length) is unusually long for serpentine receptors
• the N-terminal Ca+2 binding site is thought to function as the Ca+2 receptor through a 'Venus Flytrap' like Ca+2-binding pocket.

Compartment

cell membrane; multi-pass membrane protein

Alternative splicing

named isoforms=2

Expression

• expressed in kidney
• not expressed in brain, lung, liver, heart, skeletal muscle, or placenta

Pathology

• defects in CASR are the cause of
  • familial hypocalciuric hypercalcemia type 1
  • neonatal severe primary hyperparathyroidism
  • autosomal dominant hypoparathyroidism
  • chronic pancreatitis

More general terms

• Ca+2 sensor or Ca+2 sensing receptor
• G-protein coupled receptor; serpentine receptor
• glycoprotein

Additional terms

• autosomal dominant hypoparathyroidism; familial isolated hypoparathyroidism; autosomal dominant hypocalcemia
• Ca+2
• familial hypocalciuric hypercalcemia type I
• neonatal severe primary hyperparathyroidism
• parathyroid

Database

• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:846
• OMIM: https://mirror.omim.org/entry/145980
• OMIM: https://mirror.omim.org/entry/146200
• OMIM: https://mirror.omim.org/entry/239200
• OMIM: https://mirror.omim.org/entry/601199
• UniProt: http://www.uniprot.org/uniprot/P41180.html