Figure 1.

All-atom-scale model of a human exosome. The cross section of a 100 nm particle is shown containing some of the most common markers. Numerous types of nucleic acid molecules are represented including circular RNA (circRNA), long noncoding RNA (lncRNA), messenger RNA (mRNA), transfer RNA (tRNA), mitochondrial DNA (mtDNA), and microRNA (miRNA). Cytoskeletal proteins are commonly detected in exosomes. In this image, we are representing two fibers, actin (blue) and tubulin (yellow). Three types of chaperone proteins are shown, namely, hsp70, hsp90, and hsc70. Membrane proteins include MHC I and II as well as CD81, CD9, CD63, and integrin. Other markers including GTPase, ALIX, and TSG101 are shown. Exosomes are a rich source of metabolites (inset box), which include amino acids, cofactors, cholesterols, and many other lipid varieties. This image was generated using multiple software as previously described.²⁰ Accession numbers were obtained from the protein databank.