Inositol trisphosphate
The inositol trisphosphate trianion
| |
Names | |
---|---|
IUPAC name
[(1R,2S,3R,4R,5S,6R)-2,3,5-trihydroxy-4,6-diphosphonooxycyclohexyl] dihydrogen phosphate
| |
Other names
IP3; Triphosphoinositol; Inositol 1,4,5-trisphosphate
| |
Identifiers | |
3D model (
JSmol ) |
|
ChemSpider | |
IUPHAR/BPS |
|
PubChem CID
|
|
UNII | |
| |
| |
Properties | |
C6H15O15P3 | |
Molar mass | 420.096 g/mol |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|
Inositol trisphosphate or inositol 1,4,5-trisphosphate abbreviated InsP3 or Ins3P or IP3 is an
Properties
Chemical formula and molecular weight
IP3 is an organic molecule with a
Chemical properties
Phosphate groups can exist in three different forms depending on a solution's
Binding to its receptor
The docking of IP3 to its receptor, which is called the inositol trisphosphate receptor (InsP3R), was first studied using deletion mutagenesis in the early 1990s.[3] Studies focused on the N-terminus side of the IP3 receptor. In 1997 researchers localized the region of the IP3 receptor involved with binding of IP3 to between amino acid residues 226 and 578 in 1997. Considering that IP3 is a negatively charged molecule, positively charged amino acids such as arginine and lysine were believed to be involved. Two arginine residues at position 265 and 511 and one lysine residue at position 508 were found to be key in IP3 docking. Using a modified form of IP3, it was discovered that all three phosphate groups interact with the receptor, but not equally. Phosphates at the 4th and 5th positions interact more extensively than the phosphate at the 1st position and the hydroxyl group at the 6th position of the inositol ring.[4]
Discovery
The discovery that a
Over the next 20 years, little was discovered about the importance of PIP2 metabolism in terms of cell signaling, until the mid-1970s when Robert H. Michell hypothesized a connection between the
Further research provided valuable information on the IP3 pathway, such as the discovery in 1986 that one of the many roles of the calcium released by IP3 is to work with DAG to activate protein kinase C (PKC).[8] It was discovered in 1989 that phospholipase C (PLC) is the phosphodiesterase responsible for hydrolyzing PIP2 into DAG and IP3.[9] Today the IP3 signaling pathway is well mapped out, and is known to be important in regulating a variety of calcium-dependent cell signaling pathways.
Signaling pathway
Increases in the intracellular Ca2+ concentrations are often a result of IP3 activation. When a ligand binds to a G protein-coupled receptor (GPCR) that is coupled to a Gq heterotrimeric G protein, the α-subunit of Gq can bind to and induce activity in the PLC isozyme PLC-β, which results in the cleavage of PIP2 into IP3 and DAG.[10]
If a
IP3 (also abbreviated Ins(1,4,5)P3 is a
Function
Human
IP3's main functions are to mobilize Ca2+ from storage
In the nervous system, IP3 serves as a second messenger, with the
Sea urchin eggs
The
Research
Huntington's disease
Alzheimer's disease
See also
- Adenophostin
- Inositol
- Inositol phosphate
- myo-Inositol
- Myo-inositol trispyrophosphate
- Inositol pentakisphosphate
- Inositol hexaphosphate
- Inositol trisphosphate receptor
- ITPR1
- ITPKC
References
- ^ CID 439456 from PubChem
- PMID 15590059.
- PMID 2174351.
- PMID 15082315.
- PMID 13084667.
- PMID 164246.
- PMID 6121338.
- PMID 3014651.
- PMID 2541501.
- ^ a b Biaggioni I., Robertson D. (2011). Chapter 9. Adrenoceptor Agonists & Sympathomimetic Drugs. In: B.G. Katzung, S.B. Masters, A.J. Trevor (Eds), Basic & Clinical Pharmacology, 11e. Retrieved October 11, 2011 from "AccessMedicine | Case Study". Archived from the original on 2011-09-30. Retrieved 2011-11-30..
- ^ a b Barrett KE, Barman SM, Boitano S, Brooks H. Chapter 2. Overview of Cellular Physiology in Medical Physiology. In: K.E. Barrett, S.M. Barman, S. Boitano, H. Brooks (Eds), Ganong's Review of Medical Physiology, 23e. "AccessMedicine | Objectives". Archived from the original on 2012-06-14. Retrieved 2011-11-30..
- S2CID 4362367.
- PMID 2536419.
- PMID 18171931.
- PMID 15336977.
- ^ Alzheimer's Society of Canada. (2009). Alzheimer's Disease:What is Alzheimer's? Retrieved from: http://www.alzheimer.ca/english/disease/whatisit-intro.htm Archived 2011-12-05 at the Wayback Machine
- S2CID 20512555.
- PMID 27512009.
External links
- Inositol+1,4,5-Trisphosphate at the U.S. National Library of Medicine Medical Subject Headings (MeSH)