The Full Wiki

Inositol triphosphate: Wikis

Advertisements

Note: Many of our articles have direct quotes from sources you can cite, within the Wikipedia article! This article doesn't yet, but we're working on it! See more info or our list of citable articles.

Encyclopedia

(Redirected to Inositol trisphosphate article)

From Wikipedia, the free encyclopedia

The inositol trisphosphate trianion

Inositol trisphosphate or inositol 1,4,5-trisphosphate (also commonly known as triphosphoinositol; abbreviated InsP3 or IP3), together with diacylglycerol, is a secondary messenger molecule used in signal transduction and Lipid signaling in biological cells. While DAG stays inside the membrane, IP3 is soluble and diffuses through the cell. It is made by hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2), a phospholipid that is located in the plasma membrane, by phospholipase C.

Contents

Mechanism

IP3 binds to and activates the InsP3 receptor on the membrane of the endoplasmic reticulum (ER), and sarcoplasmic reticulum (SR), opening a calcium channel, resulting in the release of Ca2+ into the cytoplasm, and sarcoplasm respectively.[1] This increase in Ca2+ activates the ryanodine receptor-operated channel on the SR, leading to a further increase in the Ca2+.

Function

Advertisements

Human

Its main functions are to mobilize Ca2+ from storage organelles and to regulate cell proliferation and other cellular reactions.

In smooth muscle cells, for example, the increase in concentration of cytoplasmic calcium results in the contraction of the muscle cell.[2]. For further reading of Ca2+-mediated functions, see functions of calcium in humans.

Fruit fly

For example, in the fruit fly Drosophila, InsP3 is used for intracellular transduction of light recognition in eye cells.

Sea urchin eggs

The slow block to polyspermy in the sea urchin is mediated by the phosphatidyl inositol diphosphate (PIP2) secondary messenger system. Activation of the binding receptors activates phospholipase C, which cleaves PIP2 in the egg plasma membrane, releasing inositol triphosphate (IP3) into the egg cell cytoplasm. IP3 diffuses to the endoplasmic reticulum, where it opens calcium channels.

See also

External links

References

  1. ^ Ferris CD, Snyder SH. IP3 receptors. Ligand-activated calcium channels in multiple forms. Adv Second Messenger Phosphoprotein Res. 1992;26:95-107. PMID 1329896
  2. ^ Somlyo AP, Somlyo AV. Signal transduction and regulation in smooth muscle. Nature. 1994 Nov 17;372(6503):231-6. PMID 7969467

Inositol triphosphate
Identifiers
CAS number [85166-31-0]
PubChem 55310
Properties
Molecular formula C6H15O15P3
Molar mass 420.096
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox references

Inositol trisphosphate or inositol 1,4,5-trisphosphate (also commonly known as triphosphoinositol; abbreviated InsP3 or IP3), together with diacylglycerol, is a secondary messenger molecule used in signal transduction and Lipid signaling in biological cells. While DAG stays inside the membrane, IP3 is soluble and diffuses through the cell. It is made by hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2), a phospholipid that is located in the plasma membrane, by phospholipase C.

Contents

Mechanism

IP3 binds to and activates the InsP3 receptor on the membrane of the endoplasmic reticulum (ER), and sarcoplasmic reticulum (SR), opening a calcium channel, resulting in the release of Ca2+ into the cytoplasm, and sarcoplasm respectively.[1] This increase in Ca2+ activates the ryanodine receptor-operated channel on the SR, leading to a further increase in the Ca2+.

Function

Human

Its main functions are to mobilize Ca2+ from storage organelles and to regulate cell proliferation and other cellular reactions.

In smooth muscle cells, for example, the increase in concentration of cytoplasmic calcium results in the contraction of the muscle cell.[2]. For further reading of Ca2+-mediated functions, see functions of calcium in humans.

Fruit fly

For example, in the fruit fly Drosophila, InsP3 is used for intracellular transduction of light recognition in eye cells.

Sea urchin eggs

The slow block to polyspermy in the sea urchin is mediated by the phosphatidyl inositol diphosphate (PIP2) secondary messenger system. Activation of the binding receptors activates phospholipase C, which cleaves PIP2 in the egg plasma membrane, releasing inositol triphosphate (IP3) into the egg cell cytoplasm. IP3 diffuses to the endoplasmic reticulum, where it opens calcium channels.

See also

External links

References

  1. ^ Ferris CD, Snyder SH. IP3 receptors. Ligand-activated calcium channels in multiple forms. Adv Second Messenger Phosphoprotein Res. 1992;26:95-107. PMID 1329896
  2. ^ Somlyo AP, Somlyo AV. Signal transduction and regulation in smooth muscle. Nature. 1994 Nov 17;372(6503):231-6. PMID 7969467


Advertisements






Got something to say? Make a comment.
Your name
Your email address
Message