The actin cytoskeleton and plasma membrane connection: PtdIns(4,5)P(2) influences cytoskeletal protein activity at the plasma membrane.

The co-ordination of rearrangements of the actin cytoskeleton depends on its tight connection to the plasma membrane. Phosphatidylinositol 4,5-bisphosphate is thought to transmit signals originating at the plasma membrane to the underlying actin cytoskeleton. This lipid binds to, and influences the activity of, several actin-associated proteins in vitro that regulate the architecture of the actin cytoskeleton. Signalling intermediates in this process include focal adhesion molecules such as vinculin and members of two families of proteins, ERM and WASP. These proteins interact with phosphatidylinositol 4,5-bisphosphate and appear to be regulated by interplay between small GTPases and phosphatidylinositol 4,5-bisphosphate metabolism, and thus link the plasma membrane with cytoskeletal remodelling.