The recent work described here suggests that cytoskeletal-based transport is intimately coupled to other events in membrane trafficking. During membrane budding, for example, the export of secretory proteins from the TGN is likely achieved by simultaneously packaging them at the membrane and recruiting motor proteins to immediately transport nascent vesicles or to extend cargo-containing membrane tubules. Indeed, active motors have been observed to attach selectively to membrane domains at sites of concentrated cargo protein (Allan and Vale 1994xAllan, V.J. and Vale, R.D. J. Cell Sci. 1994; 107: 1885–1897PubMedSee all ReferencesAllan and Vale 1994). The connection between motors and Rabs also suggests a coordination between vesicle formation/fusion and the control of motor-based transport. Such “integration points” may also transduce information arriving from different signaling pathways to regulate the flow of vesicle formation and delivery in the secretory and endocytotic pathways. These findings on motor receptors likely mark a new era in which the molecular machinery linking motor proteins to cargo selection and delivery will be defined.‡To whom correspondence should be addressed (e-mail: vale@phy.ucsf.edu).