... with a static connection between the exocyst and Cdc42 GTP . Cdc24p, the GEF for Cdc42p, binds constitutively to Bem1p and through Bem1p to Boi1/2p (Table 1) (McCusker et al., 2007). As part of the exocyst–Boi1/2p–Sec1p complex, Cdc24p is thus placed next to the site of vesicle tethering and fusion (Fig. S6...

... a fourfold nature. Here we describe the quatrefoil complexes and other, unrelated, tethering complexes, and discuss ideas about their function. We propose that vesicle tethering may have separate kinetic and thermodynamic elements and that it may be usefully divided into events upstream and downstream...