High impact information on PARP4

• The 193-kD vault protein, VPARP, is a novel poly(ADP-ribose) polymerase [1].
• The catalytic domain of p193 was expressed and purified from bacterial extracts [1].
• We find that, like MVP, p193 mRNA and protein levels are increased in various multidrug-resistant cell lines [2].
• Furthermore, protein analysis of postnuclear supernatants and co-immunoprecipitation studies show that drug-sensitive MVP-transfected tumor cells lack this up-regulation in vault-associated p193 [2].
• As has been noted for tankyrase, sequence analysis of the Adprtl1 protein suggests that it is not capable of binding DNA directly [3].

Biological context of PARP4

• This protein now designated PH5P points to as yet unsuspected links between poly(ADP-ribose)polymerase and the inter-alpha-inhibitor family and is likely to be involved in DNA repair [4].

Physical interactions of PARP4

• However, the N-terminal half of MVP binds to a specific domain in the C-terminus of VPARP [5].

Other interactions of PARP4

• With the recent identification of the two minor vault proteins as telomerase-associated protein (TEP1) and vault-poly (ADP-ribose) polymerase (VPARP), and with high-resolution three-dimensional imaging, the composition of vaults is almost unraveled [6].
• We have subsequently refined the location of the ADPRTL1 genomic locus to 13q11, close to the recently cloned ZNF198 gene [3].
• We now report the full-length sequence, expression profile, and chromosomal localization of a novel gene, ADPRTL1, encoding an ADP-ribosyltransferase-like protein [3].
• The complex consists of a major vault protein (MVP), two minor vault proteins (VPARP and TEP1), and several small untranslated RNA molecules [7].
• Vaults are barrel-shaped cytoplasmic ribonucleoprotein particles composed of three proteins: the major vault protein (MVP), the vault poly(ADP-ribose)polymerase (VPARP), and the telomerase-associated protein 1, together with one or more small untranslated RNAs [8].

Analytical, diagnostic and therapeutic context of PARP4

• 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) [1].

References