Cell biology: Bulky tether proteins aid membrane fusion

The energy source that drives vesicle fusion with a target organelle in vivo has been unclear. It emerges that proteins that tether fusing structures together also decrease the energy needed for the final fusion step

Regulation of exocytosis by the exocyst subunit Sec6 and the SM protein Sec1

The Sec6 subunit of the multisubunit exocyst tethering complex interacts with the Sec1/Munc18 protein Sec1 and with the t-SNARE Sec9. Assembly of the exocyst upon vesicle arrival at sites of secretion is proposed to release Sec9 for SNARE complex assembly and to recruit Sec1 for interaction with SNARE complexes to facilitate fusion