p115 SNAREs a vesicle

Aprotein known to tether vesicles during intra-Golgi trafficking also ensures their correct docking, according to new results from Shorter et al. (page 45). This provides the first link between the long-range process of tethering and the short-range process of docking.

Vesicle transfer consists of four successive reactions: vesicle formation, tethering, docking, and fusion. Tethering of COP1 vesicles to the Golgi requires the coiled-coil protein p115, which links the Golgins GM130 (on the Golgi) and Giantin (on the vesicle). Subsequent docking of vesicles is a SNARE-dependent event, requiring the correct assembly of cognate SNAREs comprising one vesicle SNARE (v-SNARE) and three target SNARES (t-SNAREs). The resultant SNAREpin appears to force fusion of the two membranes.

Now, it seems that, in addition to tethering the Golgins, p115 also facilitates vesicle docking. Shorter et al. showed...