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The Vault

Short answer: Vaults are giant, hollow, barrel-shaped particles made of protein and RNA. They're found in the cytoplasm of most eukaryotic cells, with about 10,000 in a typical human cell.

Each one is a 12.9-megadalton shell made of 78 copies of the major vault protein, built as two identical 39-protein halves. It also carries smaller partners (VPARP, TEP1 and vault RNA). Nearly 40 years after their discovery in 1986, nobody knows for sure what vaults do.

VideoWrite-up7 sources

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What should you know about The Vault?

Quick facts. Each one stands alone and has a stable ID you can cite.

  1. Vaults are hollow, barrel-shaped particles in most of our cells (about 10,000 per cell), each built from 78 copies of one protein, and nobody knows for sure what they do.

    DD-015-F01 · Write-up · Exhibit B (Big and everywhere)

  2. A vault weighs about 12.9 megadaltons and is made of two identical halves of 39 major vault proteins each.

    DD-015-F02 · Write-up · Exhibit C (One protein does most of the work)

Video transcript: The Vault: Your Cells Are Full of Hollow Barrels Called Vaults

DID YOU KNOW? Vaults are enormous ribonucleoprotein particles found in the cytoplasm of most eukaryotic cells, built primarily from major vault protein, MVP, and smaller components including vault RNA and the vault poly(ADP-ribose) polymerase proteins. Each vault resembles a hollow barrel or inverted cathedral vault and has a molecular mass of roughly 12.9 megadaltons. The particles are assembled from two identical halves, each containing 39 copies of MVP arranged into a symmetrical structure, with a central cavity and flexible "cap" proteins. NOW YOU KNOW!

Burned-in captions, read frame by frame (see transcript.md) · 32.3s Reel ·

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The Vault: Your Cells Are Full of Hollow Barrels Called Vaults Instagram Reel · · 32.3s

The write-up

Your cells are full of hollow barrels called vaults. Each one is built from 78 copies of a single protein.

  1. Exhibit A

    Found by accident in 1986

    UCLA's Nancy Kedersha and Leonard Rome found vaults in 1986 while trying to purify coated vesicles from rat liver. Under the microscope the particles looked like the arches of a cathedral's vaulted ceiling, which gave them their name.

  2. Exhibit B

    Big and everywhere

    Vaults measure about 35 × 65 nm, much larger than ribosomes. Most human cells hold roughly 10,000 of them, and some immune cells may have up to 100,000.

  3. Exhibit C

    One protein does most of the work

    The shell is made of the ~100 kDa major vault protein (MVP). Vaults also carry two minor proteins, VPARP (vault poly(ADP-ribose) polymerase, 193 kDa) and TEP1 (telomerase-associated protein 1), plus small vault RNAs.

  4. Exhibit D

    12.9 megadaltons

    Vaults have a molecular mass of about 12.9 MDa. Measured at roughly 670 Å long and 400 Å wide, the hollow interior is big enough to hold most objects found in a cell.

  5. Exhibit E

    78 copies in two halves

    The X-ray structure (3.5 Å) shows the shell is 78 MVP molecules. Two identical halves of 39 MVPs each join at the 'waist', giving the particle 39-fold dihedral (D39) symmetry.

  6. Exhibit F

    Paper-thin walls, protruding caps

    The barrel wall is only about 15–25 Å thick. Each end has a protruding cap, formed by MVP's own cap-helix and cap-ring domains. The 39-fold symmetry breaks in that cap region.

  7. Exhibit G

    Still a mystery

    Despite decades of work, the vault's function is unknown. Proposed roles include intracellular transport, signalling, immunity and drug resistance, and researchers are now engineering synthetic vaults to deliver therapies.

Questions people ask about The Vault

Why are vaults called 'vaults'?

Kedersha and Rome named them for their resemblance to the multiple arches of cathedral vaults.

Source: Write-up · Exhibit A (Found by accident in 1986) · Isolation and characterization of a novel ribonucleoprotein particle (Kedersha & Rome, J. Cell Biol. 1986); The key to 'the vault' (California NanoSystems Institute, UCLA, May 27, 2024)

Roughly how many vaults does a typical human cell contain?

Most human cells have around 10,000 vaults; some immune cells may have up to 100,000.

Source: Write-up · Exhibit B (Big and everywhere) · Isolation and characterization of a novel ribonucleoprotein particle (Kedersha & Rome, J. Cell Biol. 1986); The vault complex (van Zon et al., Cell Mol Life Sci 2003, via PMC); How a scientist's lifelong obsession with vaults could transform medicine (UCLA Health)

How many copies of the major vault protein (MVP) make up one vault shell?

78 MVPs, in two identical halves of 39 each.

Source: Write-up · Exhibit E (78 copies in two halves) · Structure of Rat Liver Vault at 3.5 Å Resolution (SPring-8 Research Frontiers 2009); RCSB PDB 4HL8: Re-refinement of the vault ribonucleoprotein particle; A vault ribonucleoprotein particle exhibiting 39-fold dihedral symmetry (Kato et al., Acta Cryst D 2008)

What is a vault's approximate molecular mass?

Vaults are about 12.9 MDa, among the largest particles cells make.

Source: Write-up · Exhibit D (12.9 megadaltons) · A vault ribonucleoprotein particle exhibiting 39-fold dihedral symmetry (Kato et al., Acta Cryst D 2008); Structure of Rat Liver Vault at 3.5 Å Resolution (SPring-8 Research Frontiers 2009)

What is the known function of vaults?

Nearly 40 years after their discovery, the vault's function remains unknown.

Source: Write-up · Exhibit G (Still a mystery) · How a scientist's lifelong obsession with vaults could transform medicine (UCLA Health); The vault complex (van Zon et al., Cell Mol Life Sci 2003, via PMC); The key to 'the vault' (California NanoSystems Institute, UCLA, May 27, 2024)

Test Your Knowledge

All quizzes →

5 questions, all from this case file. Answers are revealed instantly.

  1. Why are vaults called 'vaults'?

    1. They lock away the cell's DNA
    2. Under the microscope they look like the arches of a cathedral's vaulted ceiling
    3. They were found inside bank-vault-like membranes
    4. They store the cell's energy reserves
    Show the answer

    Answer: B. Under the microscope they look like the arches of a cathedral's vaulted ceiling Kedersha and Rome named them for their resemblance to the multiple arches of cathedral vaults. Source: Write-up · Exhibit A (Found by accident in 1986) · Isolation and characterization of a novel ribonucleoprotein particle (Kedersha & Rome, J. Cell Biol. 1986); The key to 'the vault' (California NanoSystems Institute, UCLA, May 27, 2024)

  2. Roughly how many vaults does a typical human cell contain?

    1. About 10
    2. About 10,000
    3. About 10 million
    4. Exactly one
    Show the answer

    Answer: B. About 10,000 Most human cells have around 10,000 vaults; some immune cells may have up to 100,000. Source: Write-up · Exhibit B (Big and everywhere) · Isolation and characterization of a novel ribonucleoprotein particle (Kedersha & Rome, J. Cell Biol. 1986); The vault complex (van Zon et al., Cell Mol Life Sci 2003, via PMC); How a scientist's lifelong obsession with vaults could transform medicine (UCLA Health)

  3. How many copies of the major vault protein (MVP) make up one vault shell?

    1. 39
    2. 78
    3. 12
    4. 1,000
    Show the answer

    Answer: B. 78 78 MVPs, in two identical halves of 39 each. Source: Write-up · Exhibit E (78 copies in two halves) · Structure of Rat Liver Vault at 3.5 Å Resolution (SPring-8 Research Frontiers 2009); RCSB PDB 4HL8: Re-refinement of the vault ribonucleoprotein particle; A vault ribonucleoprotein particle exhibiting 39-fold dihedral symmetry (Kato et al., Acta Cryst D 2008)

  4. What is a vault's approximate molecular mass?

    1. 12.9 kilodaltons
    2. 12.9 megadaltons
    3. 129 daltons
    4. 12.9 gigadaltons
    Show the answer

    Answer: B. 12.9 megadaltons Vaults are about 12.9 MDa, among the largest particles cells make. Source: Write-up · Exhibit D (12.9 megadaltons) · A vault ribonucleoprotein particle exhibiting 39-fold dihedral symmetry (Kato et al., Acta Cryst D 2008); Structure of Rat Liver Vault at 3.5 Å Resolution (SPring-8 Research Frontiers 2009)

  5. What is the known function of vaults?

    1. They make ATP
    2. They copy DNA
    3. They build ribosomes
    4. It's still unknown
    Show the answer

    Answer: D. It's still unknown Nearly 40 years after their discovery, the vault's function remains unknown. Source: Write-up · Exhibit G (Still a mystery) · How a scientist's lifelong obsession with vaults could transform medicine (UCLA Health); The vault complex (van Zon et al., Cell Mol Life Sci 2003, via PMC); The key to 'the vault' (California NanoSystems Institute, UCLA, May 27, 2024)

Cite this case file

Easterling, Marcus. "The Vault." The Detail Department (DetailEnjoyer), case file DD-015, last updated Aug 5, 2026. https://detailenjoyer.com/case/the-vault/

Permalink: https://detailenjoyer.com/case/the-vault/ · Last updated

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