Transport to the vacuole: receptors and trans elements

Most proteins that are synthesized on membranebound ribosomes are transported through the Golgi and reach the trans-Golgi network to be sorted for delivery to various cellular destinations, including the vacuole. Sorting involves a recognition of proteins by receptors and the assembly of cytosol-oriented coat structures that package cargo into vesicles. Vesicle trafficking is regulated by specific membrane-bound and soluble proteins. Several components of the secretory machinery have recently been identified in plants and are described in this review. Ongoing and future research will characterize features of the secretory pathway specific to plants which, because of the multiplicity of vacuole types, provide a more complex paradigm than the better described mammalian and yeast systems.