FIGURE 3.

Lipid cofactors are required for fission-inducing proteins. Many AH-containing and AH-free fission-inducing proteins need specific lipids, named lipid cofactors, to promote and complete membrane fission. Thus, the ability of the fission-inducing proteins to support this process is strictly dependent on membrane lipid composition. Of note, proteins are not able to induce membrane fission in the absence of these lipids (left panel; purple dashed line). Conversely, in the presence of such lipid cofactors, fission occurs through the following steps: membrane neck, hemifission and formation of two separate membranes (right panel; green dashed line). Lipid cofactors include: PtdIns(4,5)P₂, PA, cardiolipin, MMPE, PtdIns3P, PtdIns(3,5)P₂ and cholesterol. See text for details.