Inositol triphosphate
From Wikipedia, the free encyclopedia
Inositol trisphosphate or inositol 1,4,5-trisphosphate (also commonly known as triphosphoinositol; abbreviated InsP3 or IP3), together with diacylglycerol, is a second messenger molecule used in signal transduction in biological cells. It is made by hydrolysis of phosphatidylinositol 4,5-bisphosphate, a phospholipid that is located in the plasma membrane, by phospholipase C.
Its main functions are to mobilize Ca2+ from storage organelles and to regulate cell proliferation and other cellular reactions. For example, in the fruit fly Drosophila, InsP3 is used for intracellular transduction of light recognition in eye cells.
The elevated intracellular concentration of one or more second messengers following binding of an external signaling molecule triggers a rapid alteration in the activity of one or more actions of cAMP.
Inositol tetra-, penta-, and hexa-phosphates have been implicated in gene expression by Wu 2003 and Oshea 2003 (both in Science Magazine).
 PIP2 cleavage to IP3 and DAG initiates intracellular calcium release and PKC activation. |
[edit] See also
- inositol
- inositol phosphate
- myo-inositol (inositol monophosphate).
- inositol pentakisphosphate
- inositol hexaphosphate
- inositol triphosphate receptor
[edit] External links
| Lipid signaling |
|---|
| Phospholipase | Phosphatidylinositol (4,5)-bisphosphate | Diacylglycerol | Inositol triphosphate | Inositol triphosphate receptor |
| Calcium signaling |
|---|
| Second messengers: IP3 | NAADP | cADPR |
| Intracellular calcium store gates: IP3 receptor | Ryanodine receptor | putative NAADP receptor |
| Calcium pumps and exchangers: SERCA | Na/Ca antiport | Ca/H antiport |
| calcium binding protein domains: EF hand domain | C2 domain |
| Calcium based molecular switches and kinases: troponin c | CaM | CaM kinases | PKC |
| Calcium dependent proteases: Calpain |
| Cell membrane calcium channels: VDCC | TRP | NMDA receptor | AMPA receptor | 5-HT3 receptor | P2X Receptor |
| Intracellular Calcium chelators and sensors: Calbindin | S100 | pervalbumin | Calretinin | Calsequestrin | Sarcalumenin | Phospholamban |
| Calcium regulated chaperones: calreticulin | calnexin |
| Calcium based adhesion molecules: cadherin |
| Calcium homeostasis |
| parathormone | Calcitonin | calcium receptor | vitamin D |
 |
This biochemistry article is a stub. You can help Wikipedia by expanding it. |
