Phosphatidylinositol 4,5-bisphosphate

Structural formula of PIP ₂ , R stands for the fatty acid residues capryl , oleyl , palmityl , arachidonyl or stearyl .

The phosphatidylinositol-4,5-bisphosphates (abbr. PIP ₂ ) are a group of phospholipids that occur almost exclusively in the side of the cell membrane facing the cell interior .

They play an important role in the transmission of extracellular signals in the cell and control endocytosis . By activating certain receptors located in the cell membrane, the enzyme phospholipase C is activated . Phospholipase C splits PIP ₂ by hydrolysis into diacylglycerols (DAG) and inositol-1,4,5-trisphosphate (IP ₃ ), while phospholipase A produces lysophosphatidylinositol . All three products of this split can contribute as so-called second messengers to the transmission of the signal in the cell.

Phosphoinositide-3-kinases (PI3K), on the other hand, convert PIP ₂ into phosphatidylinositol-3,4,5-triphosphate (PIP ₃ ). The reverse reaction from PIP ₃ to PIP ₂ is carried out by the phosphatase PTEN .

Web links

Wikibooks: Inositol Phosphate Metabolism - Learning and Teaching Materials

Entry at ChEBI

Individual evidence

↑ GR Hammond: Does PtdIns (4,5) P2 concentrate so it can multi-task? In: Biochemical Society transactions. Volume 44, Number 1, February 2016, pp. 228-233, doi : 10.1042 / BST20150211 , PMID 26862209 .
↑ York Posor, Marielle Eichhorn-Gruenig: Spatiotemporal control of endocytosis by phosphatidylinositol-3,4-bisphosphate. In: Nature. 499, 2013, pp. 233-237, doi : 10.1038 / nature12360 .

[1] GR Hammond: Does PtdIns (4,5) P2 concentrate so it can multi-task? In: Biochemical Society transactions. Volume 44, Number 1, February 2016, pp. 228-233, doi : 10.1042 / BST20150211 , PMID 26862209 .

[2] York Posor, Marielle Eichhorn-Gruenig: Spatiotemporal control of endocytosis by phosphatidylinositol-3,4-bisphosphate. In: Nature. 499, 2013, pp. 233-237, doi : 10.1038 / nature12360 .