Intracellular Vesicle Fusion Requires a Membrane-Destabilizing Peptide Located at the Juxtamembrane Region of the v-SNARE

Rathore, Shailendra S.; Liu, Yinghui; Yu, Haijia; Wan, Chun; Lee, MyeongSeon; Yin, Qian; Stowell, Michael H.B.; Shen, Jingshi

Next, we sought to define how the juxtamembrane motif of VAMP2 promotes membrane fusion at the molecular level. We first examined whether the juxtamembrane motif influences membrane docking. The t-SNARE liposomes were anchored to avidin beads and used to bind v-SNARE liposomes. Pairing of v-and t-SNAREs allowed the v-SNARE liposomes to dock onto the bead-anchored t-SNARE liposomes, which was moderately enhanced by Munc18-1 ( Figure 3A ). We observed that mutations of the VAMP2 juxtamembrane motif did not affect docking of the liposomes ( Figure 3A) . Hence, the juxtamembrane motif is not involved in the docking step of the membrane fusion reaction.