Roles of PIP2 in the membrane binding of MIM I-BAR: insights from molecular dynamics simulations

In order to probe the roles of PIP2 in the interactions between MIM I-BAR and model membranes, we performed a series of 10 mu s-scale coarse-grained molecular dynamics simulations. Our results indicate that PIP2 plays predominant roles in the membrane binding of MIM I-BAR in a concentration-dependent manner and via electrostatic interactions. Besides, we find that the occurrence of the membrane curvature may induce the re-distribution of lipids in the membrane and result in the local enrichment of PIP2 at negatively curved membrane areas. Combining these roles of PIP2 in the membrane binding of MIM I-BAR helps explain how MIM I-BAR senses negative curvature and, thus, contributes to maintaining membrane protrusions.