Vault (organelle)

Vault (organelle) is a cellular structure that was first described in the 1980s. Vaults are large ribonucleoprotein particles that are found in the cytoplasm of many types of eukaryotic cells, including mammals, amphibians, and mollusks. The name "vault" comes from the structure's vault-like appearance in electron micrographs.

Structure

Vaults are among the largest cytoplasmic ribonucleoprotein particles, with a mass of approximately 13 MDa. They have a distinctive barrel-like structure, which is thought to be highly conserved among different species. The vault particle is composed of multiple copies of three proteins: major vault protein (MVP), vault poly(ADP-ribose) polymerase (VPARP), and telomerase-associated protein 1 (TEP1). Additionally, vaults contain small untranslated RNA molecules, referred to as vault RNAs (vRNAs) or small vault RNAs (svRNAs), which may play a role in their function.

Function

The exact function of vaults remains largely speculative. However, they have been implicated in several cellular processes, including intracellular transport, signal transduction, and the innate immune response. Vaults are also thought to play a role in multidrug resistance in cancer cells, possibly by acting as a transport mechanism for drugs out of the cell.

Clinical Significance

Given their potential role in multidrug resistance, vaults have been studied in the context of cancer treatment. Understanding how vaults contribute to drug resistance could lead to new strategies to combat cancer. Additionally, because of their involvement in innate immunity, vaults may also have implications in the development of vaccines and antiviral therapies.

Research

Research on vaults is ongoing, with studies aimed at elucidating their structure, function, and role in disease. The development of vault-like particles for use in targeted drug delivery is a particularly active area of research, highlighting the potential therapeutic applications of these organelles.