Endogenous Vaults: Roles and functions in health and diseases

Vaults are large ribonucleoprotein particles, with a molecular weight of 13 MDa, in the cytoplasm of many eukaryotic cells. They first reported in the mid-1980s. These particles consist of the Μajor Vault Protein (MVP), the Vault Poly- (ADP-Ribose) -Polymerase (VPARP), the Telomerase-associated Protein (TEP1) and small RNAs (vRNA). There are approximately 10.000 vault particle per cell. Their majority is detected in cytoplasm, where they can interact with cytoskeletal elements. A small amount of vaults is also found to be associated with the nucleus. Little are known about the biological role of vault particles. However, their structure and their cellular detection show that these complexes have a role in intracellular transport. Recent studies support that vaults have, also a role in Multi Drug Resistance (MDR). Some other functions have also attributed to these particles, such as participation in infection process, signal pathways, cell survival and DNA repairing. Recent studies have also demonstrated that vaults have the potential to serve as transporters. Vaults could be engineered and used as nanocapsules in order to carry vaccines, drugs or other molecules in target locations and activate immune responses. Finally, preliminary findings in our laboratory, show that MVP is increased in patients with an inflammation of infectious etiology, indicating a role of vaults in infection process as it has already been supported in recent studies.