Inositol 1,4,5-trisphosphate-binding protein receptor (IPR000493)

Short name: InsP3_rcpt-bd

Family relationships


Inositol 1,4,5-trisphosphate (InsP3) is an intracellular second messenger that transduces growth factor and neurotransmitter signals. InsP3 mediates the release of Ca2+ from intracellular stores by binding to specific Ca2+ channel-coupled receptors. One such receptor contains a C-terminal Ca2+ channel with 8 possible transmembrane (TM) regions, while its N-terminal cytoplasmic region houses ligand-binding and modulatory sites [PMID: 1655411, PMID: 2165071]. Ca2+ appears to inhibit ligand binding, possibly by interacting with a Ca2+-binding protein that itself inhibits the receptor.

The InsP3 receptor is an integral membrane protein located in the endoplasmic reticulum. It is a homotetramer. The protein shows some similarity to the ryanodine receptor, which functions as a Ca2+-release channel in the sarcoplasmic reticulum of cardiac and skeletal muscle [PMID: 1645727].

GO terms

Biological Process

GO:0006816 calcium ion transport

Molecular Function

GO:0005220 inositol 1,4,5-trisphosphate-sensitive calcium-release channel activity

Cellular Component

GO:0005783 endoplasmic reticulum
GO:0016020 membrane

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.