The La RNA-binding Protein Interacts with the Vault RNA and Is a Vault-associated Protein

Department of Biological Chemistry, The David Geffen School of Medicine, University of California-Los Angeles, 33-131 CHS Mail Code 173717, 10833 Le Conte Avenue, Los Angeles, CA 90095-1737, USA.
Journal of Biological Chemistry (Impact Factor: 4.57). 11/2002; 277(43):41282-6. DOI: 10.1074/jbc.M206980200
Source: PubMed


Vaults are highly conserved ubiquitous ribonucleoprotein particles with an undefined function. Three protein species (p240/TEP1, p193/VPARP, and p100/MVP) and a small RNA comprise the 13-MDa vault particle. The expression of the unique 100-kDa major vault protein is sufficient to form the basic vault structure. Previously, we have shown that stable association of the vault RNA with the vault particle is dependent on its interaction with the p240/TEP1 protein. To identify other proteins that interact with the vault RNA, we used a UV-cross-linking assay. We find that a portion of the vault RNA is complexed with the La autoantigen in a separate smaller ribonucleoprotein particle. La interacts with the vault RNA (both in vivo and in vitro) presumably through binding to 3'-uridylates. Moreover, we also demonstrate that the La autoantigen is the 50-kDa protein that we have previously reported as a protein that co-purifies with vaults.

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    • "Guide chemical modifications (methylation and pseudouridylation) of other ncRNAs (rRNA, tRNA, snRNA); alternative splicing; in cis and trans gene regulation; may also function as miRNA Endogenous small Endo-siRNA ≈21 Interference in regulating host-gene expression and Interfering RNA transposable element transcripts Vault RNA vtRNA 86–141 Interact with both the interior and exterior of the vault particle [45] Others Transfer RNA tRNA 73–94 RNA adaptor molecule that physically links the mRNA nucleic acid sequence with the peptide amino acid sequence at the ribosome. Ribosomal RNA rRNA 121–5070 Facilitates passage of tRNAs along the mRNA during translation. "

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    • "The full potential of vaccines relies on development of effective delivery systems and adjuvants and is critical for development of successful vaccine candidates. Vaults are large cytoplasmic ribonucleoprotein (RNP) particles consisting of three proteins and a small untranslated RNA [14] [15]. Their function within cells has not been identified but reports have suggested their involvement with multidrug resistance, cell signaling and innate immunity [16] [17] [18] [19] [20] [21] [22] [23] [24]. "
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    ABSTRACT: The full potential of vaccines relies on development of effective delivery systems and adjuvants and is critical for development of successful vaccine candidates. We have shown that recombinant vaults engineered to encapsulate microbial epitopes are highly stable structures and are an ideal vaccine vehicle for epitope delivery which does not require the inclusion of an adjuvant. We studied the ability of vaults which were engineered for use as a vaccine containing an immunogenic epitope of Chlamydia trachomatis, polymorphic membrane protein G (PmpG), to be internalized into human monocytes and behave as a “natural adjuvant”. We here show that incubation of monocytes with the PmpG-1-vaults activates caspase-1 and stimulates IL-1β secretion through a process requiring the NLRP3 inflammasome and that cathepsin B and Syk are involved in the inflammasome activation. We also observed that the PmpG-1-vaults are internalized through a pathway that is transiently acidic and leads to destabilization of lysosomes. In addition, immunization of mice with PmpG-1-vaults induced PmpG-1 responsive CD4+ cells upon re-stimulation with PmpG peptide in vitro, suggesting that vault vaccines can be engineered for specific adaptive immune responses. We conclude that PmpG-1-vault vaccines can stimulate NLRP3 inflammasomes and induce PmpG-specific T cell responses.
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    • "Human telomerase RNA (hTR) and the human vault RNA (hvg1) RNAs were synthesized with the Ribomax Large-Scale RNA Production System-T7 (Promega, UK) as per the manufacturer's instructions. Telomerase RNA (hTR) was transcribed from pUC-hTR (1–451) digested with EcoRI or the same plasmid digested with StuI to generate a truncated hTR lacking the H/ACA box (nt 1–352) (3), and hvg1 RNA was transcribed from the HindIII-linearized pUC118-hvg1 (1–98) plasmid (64). Transcription products were purified using MEGAclear (Ambion, Austin, TX, USA), according to manufacturer's instructions. "
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