Top ▲

IP3 receptors C

Unless otherwise stated all data on this page refer to the human proteins. Gene information is provided for human (Hs), mouse (Mm) and rat (Rn).


Click here for help

« Hide

The inositol 1,4,5-trisphosphate receptors (IP3R) are ligand-gated Ca2+-release channels on intracellular Ca2+ store sites (such as the endoplasmic reticulum). They are responsible for the mobilization of intracellular Ca2+ stores and play an important role in intracellular Ca2+ signalling in a wide variety of cell types. Three different gene products (types I-III) have been isolated, which assemble as large tetrameric structures. IP3Rs are closely associated with certain proteins: calmodulin (CALM2, CALM3, CALM1, P62158) and FKBP (and calcineurin via FKBP). They are phosphorylated by PKA, PKC, PKG and CaMKII.

Channels and Subunits

Click here for help

IP3R1 C Show summary »

IP3R2 C Show summary »

IP3R3 C Show summary »

Target Id 745
Nomenclature IP3R3
Previous and unofficial names INSP3R3 | IP3R3 | inositol 1,4,5-triphosphate receptor 3 | IP3 receptor | IP3R3X | Itpr-3 | inositol 1
Genes ITPR3 (Hs), Itpr3 (Mm), Itpr3 (Rn)
Ensembl ID ENSG00000096433 (Hs), ENSMUSG00000042644 (Mm), ENSRNOG00000052795 (Rn)
UniProtKB AC Q14573 (Hs), P70227 (Mm), Q63269 (Rn)
Endogenous activators
cytosolic Ca2+ (nM range)
IP3 (endogenous; nM - μM range)
decavanadate (μM range)
Functional characteristics Ca2+: single-channel conductance
~88 pS (55 mM Ba2+)


Click here for help

Show »

Further reading

Click here for help

Show »

How to cite this family page

Database page citation:

IP3 receptors. Accessed on 01/03/2024. IUPHAR/BPS Guide to PHARMACOLOGY,

Concise Guide to PHARMACOLOGY citation:

Alexander SPH, Mathie AA, Peters JA, Veale EL, Striessnig J, Kelly E, Armstrong JF, Faccenda E, Harding SD, Davies JA et al. (2023) The Concise Guide to PHARMACOLOGY 2023/24: Ion channels. Br J Pharmacol. 180 Suppl 2:S145-S222.