Figure 2.

EVs functionalized with fusion proteins. (A) Design of a system for sorting mRNA into EVs using viral gag protein and the packing signal. The gag protein selectively binds the packaging signal and saturates the vesicles with mRNA. (B) The EV vector may be functionalized with an engineered fusion protein (shown in multicolor monomers) that contains an RNA binding domain (shown in red). The intravesicular domain of fusion proteins consists of an RNA-binding domain (RBD) that can bind specific miRNAs with the packaging signal. The RNA packaging signal is recognized by the RBD of fusion proteins and may stimulate the upload of miRNA into EVs. Fusion proteins may interact with an extravesicular recognition domain and form the structure required for merging with the target membrane.