Structure of a novel InsP3 receptor

EMBO J. 1991 Nov;10(11):3199-206.


Inositol 1,4,5-trisphosphate (InsP3) constitutes a major intracellular second messenger that transduces many growth factor and neurotransmitter signals. InsP3 causes the release of Ca2+ from intracellular stores by binding to specific receptors that are coupled to Ca2+ channels. One such receptor from cerebellum has previously been extensively characterized. We have now determined the full structure of a second, novel InsP3 receptor which we refer to as type 2 InsP3 receptor as opposed to the cerebellar type 1 InsP3 receptor. The type 2 InsP3 receptor has the same general structural design as the cerebellar type 1 InsP3 receptor with which it shares 69% sequence identity. Expression of the amino-terminal 1078 amino acids of the type 2 receptor demonstrates high affinity binding of InsP3 to the type 2 receptor with a similar specificity but higher affinity than observed for the type 1 receptor. These results demonstrate the presence of several types of InsP3 receptor in brain and raise the possibility that intracellular Ca2+ signaling may involve multiple pathways with different regulatory properties dependent on different InsP3 receptors.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Blotting, Northern
  • Blotting, Western
  • Calcium / metabolism
  • Calcium Channels*
  • DNA / genetics
  • Inositol 1,4,5-Trisphosphate Receptors
  • Molecular Sequence Data
  • RNA, Messenger / analysis
  • RNA, Messenger / genetics
  • Rats
  • Receptors, Cell Surface / genetics*
  • Receptors, Cell Surface / metabolism
  • Receptors, Cytoplasmic and Nuclear*
  • Sequence Alignment
  • Substrate Specificity


  • Calcium Channels
  • Inositol 1,4,5-Trisphosphate Receptors
  • RNA, Messenger
  • Receptors, Cell Surface
  • Receptors, Cytoplasmic and Nuclear
  • DNA
  • Calcium

Associated data

  • GENBANK/M60952
  • GENBANK/M60953
  • GENBANK/S58426
  • GENBANK/S58762
  • GENBANK/S60920
  • GENBANK/X56822
  • GENBANK/X60659
  • GENBANK/X60660
  • GENBANK/X60661
  • GENBANK/X61677