Fig. 6. Schematic model of GM1 C16:0 and C16:1 clustering in biological membranes, and changes upon CTxB binding.

In the absence of CTxB (top), GM1 C16:0 is found in clusters amenable to active organization dependent on PS and actin (left), while GM1 C16:1 in not clustered (right). Upon CTxB binding (bottom), clustering of underlying lipids occurs for both GM1 C16:0 (left) and GM1 C16:1 (right), independently of actin. Co-clustering with GPI-AP is limited to GM1 C16:0.