Inositol 1,4,5 trisphosphate: Difference between revisions

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Inositol 1,4,5-trisphosphate is an important [[Second messenger|second messenger]] that activates&nbsp;[[Calcium channels|calcium channels]] in the [[Endoplasmic Reticulum]].&nbsp;It is cleaved from [[PIP2|PIP]]<sub>[[PIP2|2]]</sub> by [[Phospholipase C|Phospholipase C]]&nbsp;([[Phospholipase C|PLC]])&nbsp;<ref>Molecular Biology of the Cell’ by Alberts et al (4th Edn). Chapter 15 ‘Cell Communication’ pp859-865.</ref>.<br>  
Inositol 1,4,5-trisphosphate (IP3) is a common secondary messanger used in signal transduction. When phosphatidylinositol 4,5-bisphosphate (PIP2) is hydrolysed by phospholipase C it produces IP3 and diacylglycerol (DAG).&nbsp; 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,&nbsp; leading to a huge amplification of Ca2+ in the cell.<br>


=== References''':'''  ===
=== References''':'''  ===


''<references /><br>''
''<references />Alberts et al, 2008, Mollecular biology of the Cell, 5th edition, New York, Garland publishing<br>''
 
''<references />C.H.Heldin &amp; M Purton, 1996, Signal transduction, Chapman &amp; Hall''

Revision as of 16:05, 24 November 2011

Inositol 1,4,5-trisphosphate (IP3) is a common secondary messanger used in signal transduction. When phosphatidylinositol 4,5-bisphosphate (PIP2) is hydrolysed by phospholipase C it produces IP3 and diacylglycerol (DAG).  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,  leading to a huge amplification of Ca2+ in the cell.

References:

Alberts et al, 2008, Mollecular biology of the Cell, 5th edition, New York, Garland publishing

C.H.Heldin & M Purton, 1996, Signal transduction, Chapman & Hall