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

Short name: InsP3_rcpt

Overlapping homologous superfamilies


Family relationships



The inositol 1,4,5-trisphosphate (IP3)3 receptor (IP3R) are tetrameric intracellular Ca2+ release channels on the endoplasmic membrane that are activated by the ligand IP3 [PMID: 20813840]. The mammalian IP3R family consists of three isoforms (IP3R1, IP3R2, and IP3R3). They form homotetrameric or heterotetrameric channels [PMID: 20843799]. They contain three functional domains: an N-terminal IP3-binding domain, a channel-forming domain localized to the C terminus, and a regulatory/coupling domain connecting these two domains [PMID: 20813840].

GO terms

Biological Process

GO:0006816 calcium ion transport

Molecular Function

GO:0070679 inositol 1,4,5 trisphosphate binding
GO:0005220 inositol 1,4,5-trisphosphate-sensitive calcium-release channel activity

Cellular Component

GO:0005783 endoplasmic reticulum

Contributing signatures

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