Fig. 2

Cytoplasmic calcium is controlled by IP3R and its regulators including BAP1 and PTEN in endoplasmic reticulum membrane. a Structure of CaSR proteins consist of an extracellular portion, seven transmembrane domains, and a cytoplasmic protrusion. b Endoplasmic reticulum IP3R are configured as tetramer consisting of two pairs of paired IP3R monomers. c Cell membrane integrated CaSR dimerizes and activates IP3 to localize to the ER, where IP3R tetramerizes and associates with BAP1, PTEN, or FBXL2, leading to the release of ER calcium which can activate apoptosis