Inositol trisphosphate

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Structural formula
Inositol trisphosphate
General
Surname Inositol trisphosphate
other names
  • Inositol 1,4,5-trisphosphate
  • IP 3
  • InsP 3
Molecular formula C 6 H 15 O 15 P 3
External identifiers / databases
CAS number 85166-31-0
PubChem 55310
Wikidata Q138145
properties
Molar mass 420.10 g mol −1
Physical state

firmly

safety instructions
GHS hazard labeling
no classification available
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Inositol trisphosphate (also inositol-1,4,5-trisphosphate , IP 3 for short ) is an inositol phosphate with three phosphate groups in biochemistry - it is released from a phospholipid and is important as a secondary messenger substance for signal transmission ( signal transduction ) in the cell .

Biosynthesis and other reactions

By activating a G-protein-coupled receptor or a tyrosine kinase , the membrane-bound phospholipase C is stimulated. This splits the membrane lipid phosphatidylinositol-4,5-bisphosphate (PIP 2 ) to diacylglycerol (DAG) and inositol trisphosphate.

Inositol trisphosphate is deactivated in the cell metabolism by IP 3 phosphatase to inositol bite phosphate. A further phosphorylation by the IP 3 -3-kinase (EC 2.7.1.127, three isoforms: A, B and C) at the 3-position initiates a reaction chain to further, more highly phosphorylated inositol phosphates, which also have functions in the regulation of the cell could meet.

See also

function

Inositoltrisphosphate effected through binding to its specific receptor , the IP3-receptor , the release of calcium - ions from the endoplasmic reticulum , which serves as an intracellular calcium storage. The resulting increase in the concentration of calcium in the cytosol has a variety of physiological functions. These include:

  • the contraction of the smooth muscles due to the fact that calmodulin forms a complex with the myosin light chain kinase, which causes a phosphorylation of the myosin light chain with subsequent contraction
  • the activation of protein kinase C (PKC) by 1,2-diacylglycerol, whereby the myosin light chain phosphatase is inhibited and thus the effect of the contraction is increased
  • the calmodulin -dependent activation of protein kinases .

Individual evidence

  1. This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.
  2. ^ RF Schmidt, G. Thews: Physiologie des Menschen . Springer, 2013, ISBN 978-3-642-87854-1 , pp. 18 ( limited preview in Google Book search).
  3. a b c Rosemarie Baumann: Physiology . Georg Thieme Verlag, 2010, ISBN 978-3-13-796006-5 , p. 41, 121 ( limited preview in Google Book search).
  4. Georg Löffler: Basic knowledge of biochemistry with pathobiochemistry . Springer-Verlag, 2013, ISBN 978-3-662-05984-5 , pp. 486 ( limited preview in Google Book search).

See also