Probing the PIP2 dependence of the ASAP1 PH domain membrane binding by NMR and MD simulations

Abstract

Association of the ASAP1 Pleckstrin homology (PH) domain with multiple PI(4,5)P2 at the membrane surface participates to the regulation of the small GTPase Arf1 activity. However, the effect of local PI(4,5)P2 enrichment at the membrane is unclear beyond an increased affinity of ASAP1 PH for the membrane. In particular, how PI(4,5)P2 concentration affects the docking geometry of ASAP1 PH is unknown. To determine the orientation of ASAP1 PH at the membrane interface, we explored the use of pseudo distance constraints obtained from NMR Paramagnetic Relaxation Enhancement (PRE) experiments.