Inositol 1,4,5 trisphosphate: Difference between revisions
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A small molecule involved in intracellular signalling. It is produced when the [[Inositol phospholipid signalling pathway|inositol phospholipid signalling pathway]] is activated and is one of the main factors in the release of [[Calcium|Ca<sup>2+</sup>]] [[Ions|ions]] from the [[Endoplasmic reticulum|endoplasmic reticulum]] <ref>Alberts B., Johnson A., Lewis J., Raff M., Roberts K., Walter P., (2008), Molecular Biology of the Cell, 5th Edition, New York: Garland Science</ref>. | |||
=== References | Inositol 1,4,5-trisphosphate (IP<sub>3</sub>) is a common [[Secondary messenger|secondary messenger]] used in [[Signal transduction|signal transduction]]. When [[Phosphatidylinositol 4,5-bisphosphate|phosphatidylinositol 4,5-bisphosphate]] (PIP<sub>2</sub>) is hydrolysed by [[Phospholipase C|phospholipase C]] it produces IP<sub>3</sub> and [[Diacylglycerol|diacylglycerol]] (DAG) <ref>Alberts et al, 2008, Mollecular biology of the Cell, 5th edition, New York, Garland publishing</ref>. IP<sub>3</sub> is soluble so can diffuse through the cell to its [[IP3 receptor|IP<sub>3</sub> receptor]] (InsP3R) on the [[Endoplasmic reticulum|endoplasmic reticulum]] or [[Sarcoplasmic reticulum|sarcoplasmic reticulum]]. IP<sub>3</sub> receptor acts as a [[Calcium|calcium]] ion channel, so once IP<sub>3</sub> is bound it allows the movement of [[Calcium|Ca<sup>2+</sup>]] ions from the endoplasmic reticulum into the cell down their concentration gradient. This influx of calcium causes a [[Calcium induced calcium response|calcium induced calcium response]] (CICR) which along with IP<sub>3</sub> helps to activate many more InsP3R <ref>C.H.Heldin &amp;amp;amp;amp; M Purton, 1996, Signal transduction, Chapman &amp;amp;amp;amp; Hall</ref>, leading to a huge amplification of Ca<sup>2+</sup> in the cell.<br> | ||
[[IP3|IP<sub>3</sub>]] ([[Inositol 1,4,5-trisphosphate|Inositol 1,4,5-trisphosphate]]) is a cleavage product of [[Phosphatidylinositol 4,5-bisphosphate|phosphatidylinositol 4,5-bisphosphate]] ([[Phosphatidylinositol 4,5-bisphosphate|PIP]]<sub>[[Phosphatidylinositol 4,5-bisphosphate|2]]</sub>). [[Phosphatidylinositol 4,5-bisphosphate|PIP]]<sub>[[Phosphatidylinositol 4,5-bisphosphate|2]]</sub> is a [[Phospholipid|phospholipid]] molecule cleaved into inositol 1,4,5-trisphosphate and [[Diacylglycerol|diacylglycerol]] ([[Diacylglycerol|DAG]]) by [[Phospholipase C|phospholipase C]] after hormone binding to the receptor. Inositol 1,4,5-trisphosphate binds to [[IP3 receptor|IP]]<sub>[[IP3 receptor|3]]</sub>[[IP3 receptor|receptor]] which results to the release of calcium from the [[Calcium pumps|calcium pumps]]. | |||
Also see [[Membrane transport|cell and membrane transport]] | |||
=== References === | |||
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Revision as of 06:14, 26 October 2012
A small molecule involved in intracellular signalling. It is produced when the inositol phospholipid signalling pathway is activated and is one of the main factors in the release of Ca2+ ions from the endoplasmic reticulum [1].
Inositol 1,4,5-trisphosphate (IP3) is a common secondary messenger used in signal transduction. When phosphatidylinositol 4,5-bisphosphate (PIP2) is hydrolysed by phospholipase C it produces IP3 and diacylglycerol (DAG) [2]. IP3 is soluble so can diffuse through the cell to its IP3 receptor (InsP3R) on the endoplasmic reticulum or sarcoplasmic reticulum. IP3 receptor acts as a calcium ion channel, so once IP3 is bound it allows the movement of Ca2+ ions from the endoplasmic reticulum into the cell down their concentration gradient. This influx of calcium causes a calcium induced calcium response (CICR) which along with IP3 helps to activate many more InsP3R [3], leading to a huge amplification of Ca2+ in the cell.
IP3 (Inositol 1,4,5-trisphosphate) is a cleavage product of phosphatidylinositol 4,5-bisphosphate (PIP2). PIP2 is a phospholipid molecule cleaved into inositol 1,4,5-trisphosphate and diacylglycerol (DAG) by phospholipase C after hormone binding to the receptor. Inositol 1,4,5-trisphosphate binds to IP3receptor which results to the release of calcium from the calcium pumps.
Also see cell and membrane transport
References
- ↑ Alberts B., Johnson A., Lewis J., Raff M., Roberts K., Walter P., (2008), Molecular Biology of the Cell, 5th Edition, New York: Garland Science
- ↑ Alberts et al, 2008, Mollecular biology of the Cell, 5th edition, New York, Garland publishing
- ↑ C.H.Heldin &amp;amp;amp; M Purton, 1996, Signal transduction, Chapman &amp;amp;amp; Hall