Consider the v-SNAREs that direct transport vesicles from the trans-Golgi network to the plasma membrane. They, like all other v-SNAREs, are membrane proteins that are integrated into the membrane of the ER during their biosynthesis and are then carried by transport vesicles to their destination. Thus, transport vesicles budding from the ER contain at least two kinds of v-SNAREs those that target the vesicles to the cis Golgi cisternae, and those that are in transit to the trans Golgi network to be packaged in different transport vesicles destined for the plasma membrane.

(A) Why might this be a problem?

(B) Suggest possible ways in which the cell might solve it.