Phosphatidylinositol (4,5)-bisphosphate

Phosphatidylinositol (4,5)-bisphosphate
200px
Molecular formula	C47H85O19P3
Molar mass	1047.09
CAS number	245126-95-8
PubChem	5497157
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

Please Take Over This Page and Apply to be Editor-In-Chief for this topic: There can be one or more than one Editor-In-Chief. You may also apply to be an Associate Editor-In-Chief of one of the subtopics below. Please mail us [1] to indicate your interest in serving either as an Editor-In-Chief of the entire topic or as an Associate Editor-In-Chief for a subtopic. Please be sure to attach your CV and or biographical sketch.

Overview

Phosphatidylinositol (4,5)-bisphosphate (PtdIns(4,5)P₂) is a minor phospholipid component of cell membranes. PtdIns(4,5)P₂ is enriched at the plasma membrane where it is an important substrate for a number of important signaling proteins.

Phospholipase C hydrolyzes the phosphodiester link in PtdIns(4,5)P₂ forming inositol 1,4,5-triphosphate (InsP₃) and diacylglycerol (DAG).

PtdIns(4,5)P2₂ is formed primarily by the type I phosphatidylinositol 4 phosphate 5 kinases from PI(4)P.

Class I PI 3-kinases phosphorylate PtdIns(4,5)P₂ forming phosphatidylinositol (3,4,5)-trisphosphate (PtdIns(3,4,5)P₃). Both PtdIns(3,4,5)P₃ and PtdIns(4,5)P₂ not only act as substrates for enzymes but also serve as docking phospholipids that bind specific domains that promote the recruitment of proteins to the plasma membrane and subsequent activation of signaling cascades.

Additional images

• 

  PIP2 cleavage to IP3 and DAG initiates intracellular calcium release and PKC activation.