Organelle identity and the targeting of peripheral membrane proteins

Within the secretory pathway, most proteins involved in vesicle formation, motor recruitment and vesicle tethering are not integral membrane proteins but, rather, peripheral membrane proteins recruited to the relevant organelles from the cytosol. From recent studies on diverse organelles, it appears that such recruitment is usually mediated by binding to a labile determinant, such as an activated G protein or a short-lived lipid species, whose distribution is restricted to a single organelle. This suggests that these determinants are what specify organelle identity, and raises interesting questions about how they are generated in an organelle-specific fashion.