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The 193-kD vault protein, VPARP, is a novel poly(ADP-ribose) polymerase.

Kickhoefer VA, Siva AC, Kedersha NL, Inman EM, Ruland C, Streuli M, Rome LH - J. Cell Biol. (1999)

Bottom Line: Furthermore, we show that one substrate for this vault-associated PARP activity is the MVP.Immunofluorescence and biochemical data reveal that p193 protein is not entirely associated with the vault particle, suggesting that it may interact with other protein(s).A portion of p193 is nuclear and localizes to the mitotic spindle.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Chemistry, University of California, Los Angeles School of Medicine, Los Angeles, California 90095-1737, USA. vkick@medne.tucla.edu

ABSTRACT
Mammalian vaults are ribonucleoprotein (RNP) complexes, composed of a small ribonucleic acid and three proteins of 100, 193, and 240 kD in size. The 100-kD major vault protein (MVP) accounts for >70% of the particle mass. We have identified the 193-kD vault protein by its interaction with the MVP in a yeast two-hybrid screen and confirmed its identity by peptide sequence analysis. Analysis of the protein sequence revealed a region of approximately 350 amino acids that shares 28% identity with the catalytic domain of poly(ADP-ribose) polymerase (PARP). PARP is a nuclear protein that catalyzes the formation of ADP-ribose polymers in response to DNA damage. The catalytic domain of p193 was expressed and purified from bacterial extracts. Like PARP, this domain is capable of catalyzing a poly(ADP-ribosyl)ation reaction; thus, the 193-kD protein is a new PARP. Purified vaults also contain the poly(ADP-ribosyl)ation activity, indicating that the assembled particle retains enzymatic activity. Furthermore, we show that one substrate for this vault-associated PARP activity is the MVP. Immunofluorescence and biochemical data reveal that p193 protein is not entirely associated with the vault particle, suggesting that it may interact with other protein(s). A portion of p193 is nuclear and localizes to the mitotic spindle.

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Tissue-specific expression patterns of p193 and MVP are similar. A Northern blot (Origene) containing poly(A)+ RNA from human tissues was hybridized with either a 32P-labeled probe specific for p193 (top), MVP (middle), or β-actin (bottom) as described in Materials and Methods. The tissue sources are indicated at the top of the blot.
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Figure 6: Tissue-specific expression patterns of p193 and MVP are similar. A Northern blot (Origene) containing poly(A)+ RNA from human tissues was hybridized with either a 32P-labeled probe specific for p193 (top), MVP (middle), or β-actin (bottom) as described in Materials and Methods. The tissue sources are indicated at the top of the blot.

Mentions: We determined the expression of p193 by Northern blot analysis of human tissues, including brain, heart, kidney, spleen, liver, and leukocytes (Fig. 6). In all tissues, except brain, a 5.4-kb mRNA was readily detectable in 2 μg of poly(A)+ RNA. The highest level of expression was seen in kidney, with about equal levels detectable in spleen and liver. The p193 mRNA tissue expression pattern is similar to that of MVP; however, the level of expression in individual tissues is variable, as there is a higher level of MVP mRNA in spleen compared with liver (Fig. 6).


The 193-kD vault protein, VPARP, is a novel poly(ADP-ribose) polymerase.

Kickhoefer VA, Siva AC, Kedersha NL, Inman EM, Ruland C, Streuli M, Rome LH - J. Cell Biol. (1999)

Tissue-specific expression patterns of p193 and MVP are similar. A Northern blot (Origene) containing poly(A)+ RNA from human tissues was hybridized with either a 32P-labeled probe specific for p193 (top), MVP (middle), or β-actin (bottom) as described in Materials and Methods. The tissue sources are indicated at the top of the blot.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2169495&req=5

Figure 6: Tissue-specific expression patterns of p193 and MVP are similar. A Northern blot (Origene) containing poly(A)+ RNA from human tissues was hybridized with either a 32P-labeled probe specific for p193 (top), MVP (middle), or β-actin (bottom) as described in Materials and Methods. The tissue sources are indicated at the top of the blot.
Mentions: We determined the expression of p193 by Northern blot analysis of human tissues, including brain, heart, kidney, spleen, liver, and leukocytes (Fig. 6). In all tissues, except brain, a 5.4-kb mRNA was readily detectable in 2 μg of poly(A)+ RNA. The highest level of expression was seen in kidney, with about equal levels detectable in spleen and liver. The p193 mRNA tissue expression pattern is similar to that of MVP; however, the level of expression in individual tissues is variable, as there is a higher level of MVP mRNA in spleen compared with liver (Fig. 6).

Bottom Line: Furthermore, we show that one substrate for this vault-associated PARP activity is the MVP.Immunofluorescence and biochemical data reveal that p193 protein is not entirely associated with the vault particle, suggesting that it may interact with other protein(s).A portion of p193 is nuclear and localizes to the mitotic spindle.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Chemistry, University of California, Los Angeles School of Medicine, Los Angeles, California 90095-1737, USA. vkick@medne.tucla.edu

ABSTRACT
Mammalian vaults are ribonucleoprotein (RNP) complexes, composed of a small ribonucleic acid and three proteins of 100, 193, and 240 kD in size. The 100-kD major vault protein (MVP) accounts for >70% of the particle mass. We have identified the 193-kD vault protein by its interaction with the MVP in a yeast two-hybrid screen and confirmed its identity by peptide sequence analysis. Analysis of the protein sequence revealed a region of approximately 350 amino acids that shares 28% identity with the catalytic domain of poly(ADP-ribose) polymerase (PARP). PARP is a nuclear protein that catalyzes the formation of ADP-ribose polymers in response to DNA damage. The catalytic domain of p193 was expressed and purified from bacterial extracts. Like PARP, this domain is capable of catalyzing a poly(ADP-ribosyl)ation reaction; thus, the 193-kD protein is a new PARP. Purified vaults also contain the poly(ADP-ribosyl)ation activity, indicating that the assembled particle retains enzymatic activity. Furthermore, we show that one substrate for this vault-associated PARP activity is the MVP. Immunofluorescence and biochemical data reveal that p193 protein is not entirely associated with the vault particle, suggesting that it may interact with other protein(s). A portion of p193 is nuclear and localizes to the mitotic spindle.

Show MeSH
Related in: MedlinePlus