Inositol trisphosphate receptor

See also: Ryanodine-Inositol 1,4,5-triphosphate receptor calcium channels

Inositol trisphosphate receptor (InsP3R) is a membrane glycoprotein complex acting as a Ca²⁺ channel activated by inositol trisphosphate (InsP3). InsP3R is very diverse among organisms, and is necessary for the control of cellular and physiological processes including cell division, cell proliferation, apoptosis, fertilization, development, behavior, learning and memory.^[2] Inositol triphosphate receptor represents a dominant second messenger leading to the release of Ca²⁺ from intracellular store sites. There is strong evidence suggesting that the InsP3R plays an important role in the conversion of external stimuli to intracellular Ca²⁺ signals characterized by complex patterns relative to both space and time, such as Ca²⁺ waves and oscillations.^[3]

inositol 1,4,5-trisphosphate receptor, type 1[1]
Crystal structure of the ligand binding suppressor domain of type 1 inositol 1,4,5-trisphosphate receptor
Identifiers
Symbol	ITPR1
NCBI gene	3708
HGNC	6180
OMIM	147265
RefSeq	NM_002222
UniProt	Q14643
Other data
Locus	Chr. 3 p26.1
Search for Structures Swiss-model Domains InterPro

inositol 1,4,5-trisphosphate receptor, type 2
Identifiers
Symbol	ITPR2
NCBI gene	3709
HGNC	structure of the ligand binding suppressor domain of type 1 inositol 1,4,5-trisphosphate receptor 6181 Crystal structure of the ligand binding suppressor domain of type 1 inositol 1,4,5-trisphosphate receptor 6181
OMIM	600144
RefSeq	NM_002223
UniProt	Q14571
Other data
Locus	Chr. 12 p11.23
Search for Structures Swiss-model Domains InterPro

inositol 1,4,5-trisphosphate receptor, type 3
Single-particle cryo-EM structure of the IP3-bound resting state.
Identifiers
Symbol	ITPR3
NCBI gene	3710
HGNC	6182
OMIM	147267
RefSeq	NM_002224
UniProt	Q14573
Other data
Locus	Chr. 6 p21.31
Search for Structures Swiss-model Domains InterPro

Discovery

The InsP3 receptor was first purified from rat cerebellum by neuroscientists Surachai Supattapone and Solomon Snyder at Johns Hopkins University School of Medicine.^[4]

The cDNA of the InsP3 receptor was first cloned in the laboratory of Katsuhiko Mikoshiba. The initial sequencing was reported as an unknown protein enriched in the cerebellum called P400.^[5] The large size of this open reading frame indicated a molecular weight similar to the protein purified biochemically, and soon thereafter it was confirmed that the protein p400 was in fact the inositol trisphosphate receptor.^[6]

Distribution

The receptor has a broad tissue distribution but is especially abundant in the cerebellum. Most of the InsP3Rs are found integrated into the endoplasmic reticulum.

Structure

Several X-ray crystallographic ^[7][8][9] and electron cryomicroscopic (cryo-EM) ^{[10][11][12][13][14][15][16]} structures of IP₃Rs from mouse, rat, and human have defined the overall architecture of the channel. The 1.2 MDa C4-symmetric assembly consists of an ER-embedded transmembrane domain (TMD) in a domain-swapped 6 transmembrane (6TM) cation channel fold that is capped by a large cytosolic domain (CD). In this manner, IP₃Rs share significant homology with the much larger and distantly-related RyRs.^[17] The CD contains all known ligand binding sites, including the IP₃ binding site, two Ca²⁺ binding sites, an adenine nucleotide binding site, and a C₂H₂ Zn²⁺ finger fold. A comprehensive Ca²⁺-dependent conformational landscape has been defined by cryo-EM.^[18]

See also

• Inositol
• Inositol phosphate
  • Inositol monophosphate
  • Inositol trisphosphate
  • Inositol pentakisphosphate
  • Inositol hexaphosphate
• MRVI1 associated through complex formation.

References

1. Bosanac I, Yamazaki H, Matsu-Ura T, Michikawa T, Mikoshiba K, Ikura M (January 2005). "Crystal structure of the ligand binding suppressor domain of type 1 inositol 1,4,5-trisphosphate receptor". Molecular Cell. 17 (2): 193–203. doi:10.1016/j.molcel.2004.11.047. PMID 15664189.
2. Bosanac I, Alattia JR, Mal TK, Chan J, Talarico S, Tong FK, et al. (December 2002). "Structure of the inositol 1,4,5-trisphosphate receptor binding core in complex with its ligand". Nature. 420 (6916): 696–700. Bibcode:2002Natur.420..696B. doi:10.1038/nature01268. PMID 12442173. S2CID 4422308.
3. Yoshida Y, Imai S (June 1997). "Structure and function of inositol 1,4,5-trisphosphate receptor". Japanese Journal of Pharmacology. 74 (2): 125–137. doi:10.1254/jjp.74.125. PMID 9243320.
4. Supattapone S, Worley PF, Baraban JM, Snyder SH (January 1988). "Solubilization, purification, and characterization of an inositol trisphosphate receptor". The Journal of Biological Chemistry. 263 (3): 1530–1534. doi:10.1016/S0021-9258(19)57336-7. PMID 2826483.
5. Furuichi T, Yoshikawa S, Mikoshiba K (July 1989). "Nucleotide sequence of cDNA encoding P400 protein in the mouse cerebellum". Nucleic Acids Research. 17 (13): 5385–5386. doi:10.1093/nar/17.13.5385. PMC 318125. PMID 2762133.
6. Furuichi T, Yoshikawa S, Miyawaki A, Wada K, Maeda N, Mikoshiba K (November 1989). "Primary structure and functional expression of the inositol 1,4,5-trisphosphate-binding protein P400". Nature. 342 (6245): 32–38. Bibcode:1989Natur.342...32F. doi:10.1038/342032a0. PMID 2554142. S2CID 1781700.
7. Bosanac I, Alattia JR, Mal TK, Chan J, Talarico S, Tong FK, et al. (December 2002). "Structure of the inositol 1,4,5-trisphosphate receptor binding core in complex with its ligand". Nature. 420 (6916): 696–700. Bibcode:2002Natur.420..696B. doi:10.1038/nature01268. PMID 12442173. S2CID 4422308.
8. Lin CC, Baek K, Lu Z (September 2011). "Apo and InsP₃-bound crystal structures of the ligand-binding domain of an InsP₃ receptor". Nature Structural & Molecular Biology. 18 (10): 1172–1174. doi:10.1038/nsmb.2112. PMC 3242432. PMID 21892169.
9. Seo MD, Velamakanni S, Ishiyama N, Stathopulos PB, Rossi AM, Khan SA, et al. (January 2012). "Structural and functional conservation of key domains in InsP3 and ryanodine receptors". Nature. 483 (7387): 108–112. Bibcode:2012Natur.483..108S. doi:10.1038/nature10751. PMC 3378505. PMID 22286060.
10. Fan G, Baker ML, Wang Z, Baker MR, Sinyagovskiy PA, Chiu W, et al. (November 2015). "Gating machinery of InsP3R channels revealed by electron cryomicroscopy". Nature. 527 (7578): 336–341. Bibcode:2015Natur.527..336F. doi:10.1038/nature15249. PMC 4804758. PMID 26458101.
11. Paknejad N, Hite RK (August 2018). "Structural basis for the regulation of inositol trisphosphate receptors by Ca²⁺ and IP₃". Nature Structural & Molecular Biology. 25 (8): 660–668. doi:10.1038/s41594-018-0089-6. PMC 6082148. PMID 30013099.
12. Fan G, Baker MR, Wang Z, Seryshev AB, Ludtke SJ, Baker ML, Serysheva II (December 2018). "Cryo-EM reveals ligand induced allostery underlying InsP₃R channel gating". Cell Research. 28 (12): 1158–1170. doi:10.1038/s41422-018-0108-5. PMC 6274648. PMID 30470765.
13. Azumaya CM, Linton EA, Risener CJ, Nakagawa T, Karakas E (February 2020). "Cryo-EM structure of human type-3 inositol triphosphate receptor reveals the presence of a self-binding peptide that acts as an antagonist". The Journal of Biological Chemistry. 295 (6): 1743–1753. doi:10.1074/jbc.RA119.011570. PMC 7008357. PMID 31915246.
14. Baker MR, Fan G, Seryshev AB, Agosto MA, Baker ML, Serysheva II (May 2021). "Cryo-EM structure of type 1 IP₃R channel in a lipid bilayer". Communications Biology. 4 (1): 625. doi:10.1038/s42003-021-02156-4. PMC 8149723. PMID 34035440.
15. Schmitz EA, Takahashi H, Karakas E (March 2022). "Structural basis for activation and gating of IP₃ receptors". Nature Communications. 13 (1): 1408. Bibcode:2022NatCo..13.1408S. doi:10.1038/s41467-022-29073-2. PMC 8930994. PMID 35301323.
16. Fan G, Baker MR, Terry LE, Arige V, Chen M, Seryshev AB, et al. (November 2022). "Conformational motions and ligand-binding underlying gating and regulation in IP₃R channel". Nature Communications. 13 (1): 6942. Bibcode:2022NatCo..13.6942F. doi:10.1038/s41467-022-34574-1. PMC 9663519. PMID 36376291.
17. Woll KA, Van Petegem F (January 2022). "Calcium-release channels: structure and function of IP₃ receptors and ryanodine receptors". Physiological Reviews. 102 (1): 209–268. doi:10.1152/physrev.00033.2020. PMID 34280054. S2CID 236141016.
18. Paknejad, Navid; Sapuru, Vinay; Hite, Richard K. (2023-10-28). "Structural titration reveals Ca2+-dependent conformational landscape of the IP3 receptor". Nature Communications. 14 (1): 6897. doi:10.1038/s41467-023-42707-3. ISSN 2041-1723. PMC 10613215. PMID 37898605.

External links

• Inositol+Trisphosphate+Receptor at the U.S. National Library of Medicine Medical Subject Headings (MeSH)