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).

Overview

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

743
Click here for help

Targets of relevance to immunopharmacology are highlighted in blue

IP3R1 C Show summary »


Target Id 743
Nomenclature IP3R1
Previous and unofficial names INSP3R1 | IP3R1 | SCA15 | SCA16 | spinocerebellar ataxia 15 | spinocerebellar ataxia 16 | I145TR | inositol 1,4,5-triphosphate receptor 1 | InsP3R | IP3 receptor | InsP3R type I | Ip3r | Itpr-1 | opt | Pcp1 | inositol 1 | inositol 1,4,5-trisphosphate receptor 1
Genes ITPR1 (Hs), Itpr1 (Mm), Itpr1 (Rn)
Ensembl ID ENSG00000150995 (Hs), ENSMUSG00000030102 (Mm), ENSRNOG00000007104 (Rn)
UniProtKB AC Q14643 (Hs), P11881 (Mm), P29994 (Rn)
Endogenous activators
cytosolic Ca2+ Concentration range: < 7.5x10-4 M
cytosolic ATP (< mM range)
IP3 (endogenous; nM - μM range)
Activators
adenophostin A (pharmacological; nM range)
inositol 2,4,5-trisphosphate (pharmacological; also activated by other InsP3 analogues)
Antagonists
caffeine (mM range)
PIP2 (μM range)
decavanadate (μM range)
xestospongin C (μM range)
Functional characteristics Ca2+: (PBa/PK ~6) single-channel conductance
~70 pS (50 mM Ca2+)
Comment IP3 R1 is also antagonised by calmodulin at high cytosolic Ca2+ concentrations

IP3R2 C Show summary »

IP3R3 C Show summary »

Comments

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 13/12/2024. IUPHAR/BPS Guide to PHARMACOLOGY, http://www.guidetopharmacology.org/GRAC/FamilyDisplayForward?familyId=123.

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.