Mechanical Tension Drives Cell Membrane Fusion

• DOI: 10.1016/j.devcel.2015.01.005
• Publication Date: 2015-02-12T18:50:32Z
• Authors: Ji Hoon Kim; Yixin Ren; Win Pin Ng; Shuo Li; Sungmin Son; Yee-Seir Kee; Shiliang Zhang; Guofeng Zhang; Daniel A. Fletcher; Douglas N. Robinson; Elizabeth H. Chen
• Keywords: Myosin Type II; rho GTP-Binding Proteins; rho-Associated Kinases; 0303 health sciences; Reverse Transcriptase Polymerase Chain Reaction; Blotting, Western; Cell Membrane; Lipid Bilayers; Apoptosis; Cell Communication; Real-Time Polymerase Chain Reaction; Mechanotransduction, Cellular; Membrane Fusion; Models, Biological; Immunoenzyme Techniques; 03 medical and health sciences; Drosophila melanogaster; Animals; Immunoprecipitation; RNA, Messenger; Cells, Cultured; Developmental Biology; Cell Proliferation

Membrane fusion is an energy-consuming process that requires tight juxtaposition of two lipid bilayers. Little is known about how cells overcome energy barriers to bring their membranes together for fusion. Previously, we have shown that cell-cell fusion is an asymmetric process in which an "attacking" cell drills finger-like protrusions into the "receiving" cell to promote cell fusion. Here, we show that the receiving cell mounts a Myosin II (MyoII)-mediated mechanosensory response to its invasive fusion partner. MyoII acts as a mechanosensor, which directs its force-induced recruitment to the fusion site, and the mechanosensory response of MyoII is amplified by chemical signaling initiated by cell adhesion molecules. The accumulated MyoII, in turn, increases cortical tension and promotes fusion pore formation. We propose that the protrusive and resisting forces from fusion partners put the fusogenic synapse under high mechanical tension, which helps to overcome energy barriers for membrane apposition and drives cell membrane fusion.