title: Tyrosine kinase-dependent release of an adenovirus preterminal protein complex from the nuclear matrix.
abstract: Adenovirus (Ad) replicative complexes form at discrete sites on the nuclear matrix (NM) through the interaction of Ad preterminal protein (pTP). The NM is a highly salt-resistant fibrillar network which is known to anchor transcription, mRNA splicing, and DNA replication complexes. Incubation of rATP with NM to which pTP was bound caused the release of pTP as a pTP-NM complex with a size of 220 to 230 kDa; incubation with 5' adenylylimidodiphosphate (rAMP-PNP) showed no significant release, indicating that rATP hydrolysis was required. With NM extracts, it was shown that a pTP-NM complex which was capable of binding Ad origin DNA could be reconstituted in vitro. A number of high-molecular-weight NM proteins ranging in size from 120 to 200 kDa were identified on Far Western blots for their ability to bind pTP. rATP-dependent release of pTP from the NM was inhibited in a dose-dependent fashion by the addition of tyrosine kinase inhibitors, such as quercetin, methyl-2,5-dihydroxycinnamate, or genistein. NM-mediated phosphorylation of a poly(Glu, Tyr) substrate was also significantly abrogated by the addition of these compounds. rATP-dependent release of Ad DNA termini bound to the NM via pTP was also blocked by the addition of these inhibitors. These results indicate that a tyrosine kinase mechanism controls the release of pTP from its binding sites on the NM. These data support the concept that phosphorylation may play a key role in the modulation of pTP binding sites on the NM.
authors.affiliation: Department of Biochemistry and Molecular Genetics, Schools of Medicine and Dentistry, University of Alabama at Birmingham, 35294-0005, USA.
authors.forename: P C
authors.initials: PC
authors.lastname: Angeletti
authors.forename: J A
authors.initials: JA
authors.lastname: Engler
mesh_terms: D000260:Adenoviruses, Human / Q000378:metabolism / Q000502:physiology*; D000266:Adenylyl Imidodiphosphate / Q000378:metabolism; D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal; D001483:Base Sequence; D003593:Cytoplasm / Q000378:metabolism; D004261:DNA Replication; D004591:Electrophoresis, Polyacrylamide Gel; D006367:HeLa Cells; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D015530:Nuclear Matrix / Q000378:metabolism*; D009687:Nuclear Proteins / Q000032:analysis / Q000378:metabolism*; D009838:Oligodeoxyribonucleotides; D010446:Peptide Fragments / Q000737:chemistry / Q000276:immunology; D010750:Phosphoproteins / Q000032:analysis / Q000378:metabolism*; D010766:Phosphorylation; D011498:Protein Precursors / Q000032:analysis / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D012326:RNA Splicing; D012333:RNA, Messenger / Q000378:metabolism; D014158:Transcription, Genetic; D014764:Viral Proteins; D014779:Virus Replication
chemical_list: D000911:Antibodies, Monoclonal; D009687:Nuclear Proteins; D009838:Oligodeoxyribonucleotides; D010446:Peptide Fragments; D010750:Phosphoproteins; D011498:Protein Precursors; D012333:RNA, Messenger; D014764:Viral Proteins; C085476:pTP protein, adenovirus; D000266:Adenylyl Imidodiphosphate; D011505:Protein-Tyrosine Kinases