Module 3: Figure InsP3R structure

Structural organization of the inositol 1,4,5-trisphosphate (InsP3) receptor.

The inositol 1,4,5-trisphosphate receptor (InsP3R) can be divided into three functional domains (see yellow boxes). The transmembrane and pore domain has six transmembrane (TM) domains with a pore (P) domain located between TM5 and TM6. There is a short C-terminal tail containing two highly conserved thiol groups. There is a very long N-terminal region that comprises an InsP3R-binding domain that is connected to TM1 by a modulatory domain. The way in which these subunits are thought to interact to form a functional channel is illustrated in Module 3: Figure InsP3R activation.