Figure 6.

A schematic model of the two types of fatty acid modifications and secretion of TG-A. TG-A is co-translationally N-myristoylated and subsequently S-palmitoylated probably on the cytoplasmic face of the ER/Golgi membrane. The dually fatty acid-modified TG-A is finally transported to the MVBs by unknown mechanisms and secreted as exosomes following activation by external stimuli, such as bacteria-derived uracil. The secreted TG-A retains the fatty acid modification and locates in the inner leaflet of the exosomes.