Cell Signaling Technology

Phospholipid Binding: PH Domain

The PH domain from rat PLC δ1 bound to Ins(1,4,5)P3 (red).

Domain Binding and Function

Pleckstrin-homology (PH) domains are found in a wide variety of signaling proteins that associate with membranes. Some PH domains bind with high affinity (low µM or nM Kd) to specific phosphoinositides such as phosphatidylinositol- 4,5-bisphosphate, PI-3, 4-P2 or PI-3,4,5-P3. Binding to phosphoinositides may allow PH proteins to respond to lipid messengers for example by relocation to membranes. The C-termini of some PH domains have also been reported to bind the β/γ subunits of heterotrimeric G-proteins.

Structure Reference

  1. Ferguson, K.M. et al. (1995) Cell 83(6), 1037–1046.

Examples of Domain Proteins

Binding Examples

PH Domain Proteins Specific Phosphoinositide Ligands
Phospholipase C-δ; mSos1 PI-(4,5)-P2
Btk Tyr Kinase; Grp1 PI-(3,4,5)-P3
Akt/PKB Ser/Thr Kinase PI-(3,4)-P2

Reference