Vault RNP particles, also known as vaults, are large ribonucleoprotein particles found in the eukaryotic cytoplasm. They are typically found in the shape of a hollow cube, resembling the vaults of a cathedral, hence their name. Vaults are present in various organisms, including mammals, and are believed to be a universal feature of eukaryotic cells.
Vaults are composed of multiple copies of three different proteins, termed the major vault protein (MVP), the vault poly(ADP-ribose) polymerase (VPARP), and the telomerase-associated protein 1 (TEP1). Additionally, vaults also contain a small non-coding RNA molecule known as the vault RNA (vRNA). The MVP protein forms the structural framework of the vault particle, while VPARP and TEP1 are involved in various cellular processes and may provide additional functions to the vaults.
The exact biological function of vaults remains largely unknown, but they have been hypothesized to play roles in cellular transport, drug resistance, and innate immune responses. Vaults have been found to be localized in the vicinity of nuclear pores, suggesting a potential involvement in the transport of molecules between the nucleus and the cytoplasm. Additionally, certain studies have implicated vaults in drug resistance mechanisms, implying their possible role in protecting cells from the effects of chemotherapy drugs.
Further research is necessary to fully understand the complex biology and function of vaults. Their unique structural features and presence in various organisms highlight their significance in cellular processes and make them an intriguing area of study for cell and molecular biologists.
