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Minimizing the VPARP MVP interaction domain and implications in engineering new vault function
Author(s) -
Pupols Melody D,
Kickhoefer Valerie A,
Rome Leonard H
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.5.lb60-a
Subject(s) - vault (architecture) , ribonucleoprotein , microbiology and biotechnology , cytoplasm , function (biology) , ribonucleoprotein particle , heterologous , chemistry , biology , computational biology , rna , biophysics , biochemistry , gene , structural engineering , engineering
Vaults are large macromolecular assemblies composed of the 100 kDa major vault protein (MVP), the 193 kDa vault poly(ADP)ribose polymerase (VPARP), the 240 kDa telomerase/vault asssociated protein (TEP1), and one or more related small RNAs (vRNA). About 75% of the particle mass is composed of the MVP. Their ubiquitous expression, high copy number, conserved morphology, and composition all indicate they have an important yet undefined cellular function. The vault ribonucleoprotein complex is primarily localized to the cytoplasm and about ~5% are thought to associate with the nucleus near nuclear pore complexes. VPARP is a member of the PARP family of proteins. In purified vaults VPARP retains its enzymatic activity and ADP ribosylates itself and MVP. VPARP is the only vault component identified to date with an enzymatic activity and has been shown to produce short polymers of ADP‐ribose units. VPARP associates with the vault complex by binding MVP. Currently, the VPARP minimum MVP interaction domain, (m)int, is 163 amino acids. Our lab has fused this domain to heterologous proteins such as GFP and luciferase to package them inside of vaults. Our hypothesis is that the (m)int domain can be minimized further. This would allow larger heterologous proteins to be packaged into vaults and ultimately would facilitate use of the vault particle as a protein targeting device. This work was supported in part by NationalScience Foundation Grants MCB‐0210690 .