Abstract
SignificancePhosphatidylinositol 4,5-bisphosphate (PI(4,5)P(2)) levels regulate cell membrane voltage by gluing two halves of a K(+) channel together and opening the pore. PI(4)P competes with this process. Because both of these lipids are relatively abundant in the plasma membrane and are directly interconvertible through the action of specific enzymes, they may function together to regulate channel activity.