The role of receptors in targeting soluble proteins from the secretory pathway to the vacuole : Targeting and glycosylation of plant secretory proteins

The processes by which soluble proteins in the secretory pathway are sorted and targeted to the vacuole remain to be elucidated. Sorting determinants identified to date are located within a propeptide on the vacuolar protein. One potential sorting receptor has been characterized ; BP-80 (binding protein of 80 kDa) which is involved in sorting barley proaleurain to the vacuole. We discuss the evidence for at least two different vacuolar targeting pathways and the role of potential receptors in these pathways.