Structural Domains of Vault Proteins: A Role for the Coiled Coil Domain in Vault Assembly

Zon, Arend van; Mossink, Marieke H.; Schoester, M.; Scheffer, George L.; Scheper, Rik J.; Sonneveld, T.; Wiemer, Erik A.C.

doi:10.1006/bbrc.2002.6472

Cited by 52 publications

(84 citation statements)

References 32 publications

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“…For this, we first searched any putative structural or functional domains in MVP. As reported by van Zon et al (42), the MVP molecule contains three putative EF hand repeats in the N-terminal half and a coiled-coil conformation in the C-terminal half. EF hand is a helix-loop-helix motif.…”

Section: The C2 Domain Of Pten Interacts With the Ef Hand Pair Of Mvp-supporting

confidence: 54%

“…Each vault particle contains ϳeight VPARP, two telomerase-associated protein 1, and 96 MVP molecules. Recently, van Zon et al (42) characterized the function of each structural domain of these three proteins for the assembly of the vault particles. It was found that MVP self-associates through its C-terminal coiled-coil sequence and interacts with VPARP through its N-terminal region.…”

Section: Fig 4 Pten Interacts With Mvp In Vitro In a Camentioning

confidence: 99%

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PTEN Associates with the Vault Particles in HeLa Cells

Fotouhi‐Ardakani

et al. 2002

Journal of Biological Chemistry

104

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PTEN is a tumor suppressor that primarily dephosphorylates phosphatidylinositol 3,4,5-trisphosphate to down-regulate the phosphoinositide 3-kinase/Akt signaling pathway. Although the cellular functions of PTEN as a tumor suppressor have been well characterized, the mechanism by which PTEN activity is modulated by other signal molecules in vivo remains poorly understood. In searching for potential PTEN modulators through protein-protein interaction, we identified the major vault protein (MVP) as a dominant PTENbinding protein in a yeast two-hybrid screen. MVP is the major structural component of vault, the largest intracellular ribonucleoprotein particle. PTEN was originally identified as a tumor suppressor gene based on its high frequency of mutation in a variety of tumors (1-3). Germ-line mutations of PTEN are the cause of Cowden disease, an autosomal-dominant hamartoma syndrome that results in an increased risk for development of tumors in a variety of tissues (4 -7). The genetic evidence that PTEN is an important tumor suppressor is supported by the fact that heterozygous disruption of the PTEN gene in knockout mice results in the spontaneous development of tumors (8 -10). Although PTEN as a protein phosphatase is capable of dephosphorylating tyrosine and threonine/serine residues (11, 12), the primary substrates of PTEN are 3Ј-phosphoinositides, PtdIns-3,4-P 2 and PtdIns-3,4,5-P 3 (13). Genetic and biochemical studies have demonstrated that the tumor suppressor functions of PTEN are linked primarily with the lipid phosphatase activity and its association with the well defined phosphoinositide 3-kinase pathway (reviewed in Refs. 14 -20). Substantial progress has been made in the characterization of PTEN as a tumor suppressor as well as in the regulation of many cellular processes including growth, adhesion, migration, invasion, and apoptosis. Nevertheless, the mechanism by which PTEN activity is modulated in various cellular signaling complexes remains elusive. It is assumed that the activity and the cellular function of PTEN may be regulated through in vivo proteinprotein interactions. PTEN contains a number of putative regulatory modules, including the N-terminal phosphoinositide binding motif, a C2 domain, a PDZ-binding site, and two proline-, glutamic acid-, serine-, and threonine-rich segments (21). The C2 domain of PTEN has been implicated in mediating membrane association (22). The C-terminal tail of PTEN interacts with several PDZ domain-containing proteins such as hDLG, hMAST205, MAGI-2, and MAGI-3 (23-25). The interaction of PTEN with these proteins may be important for its biological function, as it has been reported that MAGI-2 and MAGI-3 can enhance the activity of PTEN (23, 24). In contrast, several groups found that the PDZ-binding site of PTEN is not required for tumor suppression or other biological activities (21,(25)(26)(27)(28). Therefore, the complete spectrum of PTEN-interacting proteins and the effects of the interactions on PTEN function are not yet defined.To date, the vault complex w...

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Section: The C2 Domain Of Pten Interacts With the Ef Hand Pair Of Mvp-supporting

confidence: 54%

Section: Fig 4 Pten Interacts With Mvp In Vitro In a Camentioning

confidence: 99%

PTEN Associates with the Vault Particles in HeLa Cells

Fotouhi‐Ardakani

et al. 2002

Journal of Biological Chemistry

104

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“…All attempts have thus far been unsuccessful (data not shown). As MVP has been shown to bind calcium, we have also treated vaults with various concentrations of EGTA or calcium chloride to no avail (36). We considered the possibility that since endogenous vaults in extracts are much less protective of the associated VR than are purified vaults, a soluble factor that facilitates the opening of vaults could be present in extracts and then lost during purification.…”

Section: Discussionmentioning

confidence: 99%

The Vault Exterior Shell Is a Dynamic Structure that Allows Incorporation of Vault-Associated Proteins into Its Interior

et al. 2006

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Vaults are 13 million Dalton ribonucleoprotein particles with a highly conserved structure. Expression and assembly by multimerization of an estimated 96 copies of a single protein, termed the major vault protein (MVP), is sufficient to form the minimal structure and entire exterior shell of the barrel-shaped vault particle. Multiple copies of two additional proteins, VPARP and TEP1, and a small untranslated vault RNA are also associated with vaults. We used the Sf9 insect cell expression system to form MVP-only recombinant vaults and performed a series of protein-mixing experiments to test whether this particle shell is able to exclude exogenous proteins from interacting with the vault interior. Surprisingly, we found that VPARP and TEP1 are able to incorporate into vaults even after the formation of the MVP vault particle shell is complete. Electrospray molecular mobility analysis and spectroscopic studies of vault-interacting proteins were used to confirm this result. Our results demonstrate that the protein shell of the recombinant vault particle is a dynamic structure and suggest a possible mechanism for in vivo assembly of vault-interacting proteins into preformed vaults. Finally, this study suggests that the vault interior may be functionally interactive with the cellular milieu.Vaults are structurally conserved ribonucleoprotein (RNP) 1 particles that have been implicated in multidrug resistance, nucleocytoplasmic transport, and as scaffolds for both epidermal growth factor signaling and interferon-gamma activated JAK/STAT signaling pathways; however, their precise function remains unclear (1-9). The particles have a capped-barrel morphology with dimensions of approximately 41 × 41 × 72.5 nm (10), and at 13 million Daltons, are the largest known RNP. Vaults have 8-fold symmetry around their longitudinal axis and each half-vault appears identical (8-2-2 symmetry). When plated onto poly-L-lysine coated electron microscopy grids and visualized by freeze-etch platinum shadowing, vaults † This research was supported by grants from the National Science Foundation (MCB-0210690 and CHE-0507929) and the G. Harold and Leila Y. Mathers Charitable Foundation (01124244). The UCLA Functional Proteomics Center was established and equipped by a grant from the W. M. Keck Foundation. JAL acknowledges support from the Jonsson Comprehensive Cancer Center at UCLA, the UCLA-DOE Institute for Genomics and Proteomics, and the National Institutes of Health (RR 20004).*To whom all correspondence should be addressed: Leonard H. Rome, Department of Biological Chemistry, University of California, Los Angeles, 33-131 CHS mail code #173717, 10833 Le Conte Avenue, Los Angeles, California 90095-1737, Tel. 310 825-0709; Fax. 310 206-5272; Email: lrome@mednet.ucla.edu. 1 ABBREVIATIONS: RNP, ribonucleoprotein; MVP, major vault protein; TEP1, telomerase associated protein 1; VPARP, vault poly (ADP-ribose) polymerase; VR, vault RNA; cryoEM, cryoelectron microscopy; TEM, transmission electron microscopy; M-INT, minimal MVP interactio...

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“…Primers are listed in Supplementary Table 1. Y2H analysis Y2H was performed using yeast strain PJ69-4A (Dr Philip James, University of Wisconsin, Madison, WI, USA) as described (James et al, 1996;van Zon et al, 2002). As prey library, a mouse 17-day embryo cDNA library (Matchmaker, Clontech Laboratories, Palo Alto, CA, USA) was used.…”

Section: Pcr Primersmentioning

confidence: 99%