EOG8QC3MX GO:0005220 1/3 inositol 1,4,5-trisphosphate-sensitive calcium-release channel activity molecular_function "Enables the transmembrane transfer of a calcium ion by a channel that opens when inositol 1,4,5-trisphosphate (IP3) has been bound by the channel complex or one of its constituent parts." [GOC:mah, GOC:signaling, PMID:8660280, Wikipedia:Inositol_trisphosphate_receptor] EOG8QC3MX GO:0016020 1/3 membrane cellular_component "A lipid bilayer along with all the proteins and protein complexes embedded in it an attached to it." [GOC:dos, GOC:mah, ISBN:0815316194] EOG8QC3MX GO:0005783 1/3 endoplasmic reticulum cellular_component "The irregular network of unit membranes, visible only by electron microscopy, that occurs in the cytoplasm of many eukaryotic cells. The membranes form a complex meshwork of tubular channels, which are often expanded into slitlike cavities called cisternae. The ER takes two forms, rough (or granular), with ribosomes adhering to the outer surface, and smooth (with no ribosomes attached)." [ISBN:0198506732]