Phosphatidylinositol 3-phosphate

Phosphatidylinositol 3-phosphate (PI3P) is a phospholipid found in cell membranes that helps to recruit a range of proteins, many of which are involved in protein trafficking, to the membranes. It is the product of both the class II and III phosphoinositide 3-kinases (PI 3-kinases) activity on phosphatidylinositol.^[1]

Phosphatidylinositol 3-phosphate

Names
Other names sn-1-stearoyl-2-arachidonoyl phosphatidylinositol 3-phosphate
Identifiers
Abbreviations	PtdIns3P PtdIns(3)P PI3P PI(3)P
PubChem CID	6857403
CompTox Dashboard (EPA)	DTXSID701343991
Properties
Chemical formula	C11H20O16P2
Molar mass	470.214 g/mol, neutral with fatty acid composition - 18:0, 20:4
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

PtdIns3P is dephosphorylated by the myotubularin family of phosphatases, on the D3 position of the inositol ring, and can be converted to PtdIns(3,5)P₂ by the lipid kinase PIKfyve.^[2]

Both FYVE domains and PX domains – found in proteins such as SNX1, HGS, and EEA1 – bind to PtdIns3P.^[3]

The majority of PtdIns3P appears to be constitutively synthesised by the class III PI 3-kinase, PIK3C3 (Vps34), at endocytic membranes. Class II PI 3-kinases also appear to synthesise PtdIns3P, their activity however appears to be regulated by a range of stimuli, including growth factors. This suggests that specific pools of PtdIns3P may be synthesised upon cell stimulation.

See also

• Phosphatidylinositol 3-phosphate-binding protein 2

References

1. Gillooly DJ, Simonsen A, Stenmark H (April 2001). "Cellular functions of phosphatidylinositol 3-phosphate and FYVE domain proteins". The Biochemical Journal. 355 (Pt 2): 249–58. doi:10.1042/0264-6021:3550249. PMC 1221734. PMID 11284710.
2. De Craene JO, Bertazzi DL, Bär S, Friant S (March 2017). "Phosphoinositides, Major Actors in Membrane Trafficking and Lipid Signaling Pathways". International Journal of Molecular Sciences. 18 (3): 634. doi:10.3390/ijms18030634. PMC 5372647. PMID 28294977.
3. Stenmark H, Aasland R, Driscoll PC (February 2002). "The phosphatidylinositol 3-phosphate-binding FYVE finger". FEBS Letters. 513 (1): 77–84. Bibcode:2002FEBSL.513...77S. doi:10.1016/s0014-5793(01)03308-7. PMID 11911884.