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Abstract
Replication of the adenovirus genome is catalysed by adenovirus DNA polymerase in which the adenovirus preterminal protein acts as a protein primer. DNA polymerase and preterminal protein form a heterodimer which, in the presence of the cellular transcription factors NFI/CTFI and NFIII/Oct-1, binds to the origin of DNA replication. DNA replication is initiated by DNA polymerase mediated transfer of dCMP onto preterminal protein. Further DNA synthesis is catalysed by DNA polymerase in a strand displacement mechanism which also requires adenovirus DNA binding protein. Here, we discuss the role of individual proteins in this process as revealed by biochemical analysis, mutagenesis and molecular modelling.
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Affiliation(s)
- H Liu
- Centre for Biomolecular Science, Biomolecular Science Building, The University of St. Andrews, North Haugh, St. Andrews, KY16 9ST, UK
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2
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Ramachandra M, Sasaguri Y, Nakano R, Padmanabhan R. Heterologous expression, purification, and characterization of adenovirus DNA polymerase and preterminal protein. Methods Enzymol 1996; 275:168-94. [PMID: 9026638 DOI: 10.1016/s0076-6879(96)75012-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- M Ramachandra
- Laboratory of Molecular Biology, National Cancer Institute, Bethesda, Maryland 20892, USA
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3
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Affiliation(s)
- P C Van der Vliet
- Laboratory for Physiological Chemistry, University of Utrecht, The Netherlands
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4
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Ramachandra M, Padmanabhan R. Expression, Nuclear Transport, and Phosphorylation of Adenovirus DNA Replication Proteins. Curr Top Microbiol Immunol 1995. [DOI: 10.1007/978-3-642-79499-5_3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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5
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Hay RT, Freeman A, Leith I, Monaghan A, Webster A. Molecular interactions during adenovirus DNA replication. Curr Top Microbiol Immunol 1995; 199 ( Pt 2):31-48. [PMID: 7555069 DOI: 10.1007/978-3-642-79499-5_2] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- R T Hay
- School of Biological and Medical Sciences, University of St. Andrews, Scotland, UK
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6
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Roovers DJ, van der Lee FM, van der Wees J, Sussenbach JS. Analysis of the adenovirus type 5 terminal protein precursor and DNA polymerase by linker insertion mutagenesis. J Virol 1993; 67:265-76. [PMID: 8416372 PMCID: PMC237360 DOI: 10.1128/jvi.67.1.265-276.1993] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
A series of adenovirus type 5 precursor terminal protein (pTP) and DNA polymerase (Ad pol) genes with linker insertion mutations were separately introduced into the vaccinia virus genome under the control of a late vaccinia virus promoter. The recombinant viruses were used for overexpression of the mutant genes in HeLa cells. In total, 22 different mutant pTP and 10 different Ad pol vaccinia virus recombinants were constructed, including some that expressed carboxyl-terminus-truncated forms of both proteins and one that produced the mutant H5ts149 Ad pol. To investigate the structure-function relationships of both proteins, extracts from cells infected with the recombinant viruses were tested for in vitro complementation of the initiation and elongation steps in adenovirus DNA replication. The results were in accordance with those of earlier in vivo experiments with these insertion mutants and indicate that multiple regions of both proteins are essential for adenovirus DNA replication. The carboxyl termini of both pTP and Ad pol were shown to be essential for proper functioning of these proteins during initiation of adenovirus DNA replication. Three different DNA replication-negative pTP mutants were shown to have residual activity in the initiation assay, suggesting not only that pTP is required for initiation but also that it may play a role in DNA replication after the deoxycytidylation step.
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Affiliation(s)
- D J Roovers
- Laboratory for Physiological Chemistry, State University of Utrecht, The Netherlands
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7
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Nakano R, Zhao LJ, Padmanabhan R. Overproduction of adenovirus DNA polymerase and preterminal protein in HeLa cells. Gene X 1991; 105:173-8. [PMID: 1937014 DOI: 10.1016/0378-1119(91)90148-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Adenovirus (Ad) DNA polymerase (AdPol) and the preterminal protein (pTP) form a complex that is involved in the in vitro initiation of Ad DNA replication. Recombinant vaccinia viruses (vv) were constructed in which the genes encoding AdPol and pTP were cloned into a vaccinia/T7 hybrid expression-based vector downstream from the T7 promoter (pT7)/encephalomyocarditis virus (EMCV) 5'-untranslated region (UTR). HeLa cells infected with the recombinant vv-AdPol or vv-pTP or a mixture of both, together with the vv expressing T7 RNA polymerase produced significant levels of pTP and AdPol which were biologically active in the in vitro initiation of Ad DNA replication. These amounts of pTP and AdPol were only about two-fold less than the levels produced in insect cells infected with the recombinant baculovirus constructs expressing AdPol and pTP.
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Affiliation(s)
- R Nakano
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City 66103
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Fredman JN, Pettit SC, Horwitz MS, Engler JA. Linker insertion mutations in the adenovirus preterminal protein that affect DNA replication activity in vivo and in vitro. J Virol 1991; 65:4591-7. [PMID: 1870189 PMCID: PMC248913 DOI: 10.1128/jvi.65.9.4591-4597.1991] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Eighteen linker insertion mutants with mutations in the adenovirus precursor to terminal protein (pTP), which were originally constructed and tested in virions by Freimuth and Ginsberg (Proc. Natl. Acad. Sci. USA 83:7816-7820, 1986), were transferred to expression plasmids for assay of the various functions of the isolated pTP. Function was measured by the ability of individual pTP mutant proteins to participate in the initiation of replication from an adenovirus DNA end, by their activity in assays of DNA elongation, and by the intracellular distribution of pTP demonstrated by indirect immunofluorescence. Ten of the 11 mutants that were active in virion formation were also functional in DNA replication reactions in extracts, while 1 had reduced function. Four mutants with mutations that were lethal to virus production were also inactive in DNA replication reactions. These four mutations are probably located at sites required for the function of pTP in DNA synthesis. Three pTP mutants with mutations that were lethal or partially defective with respect to virion formation were active in reactions requiring pTP for initiation and elongation in extracts. All three of these mutant pTPs targeted normally to the nucleus, suggesting a defect after this step in replication. Since pTP has been reported to bind the nuclear matrix, these pTP mutants may have mutations that define sites necessary for binding to this structure. Several mutants with mutations that lie outside the putative nuclear targeting region were aberrantly localized, suggesting either that additional domains are important in nuclear localization or that there are alterations in protein structure that affect nuclear transport for some pTP mutants.
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Affiliation(s)
- J N Fredman
- Department of Biochemistry, University of Alabama, Birmingham 35294
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Chan BS, Court DA, Vierula PJ, Bertrand H. The kalilo linear senescence-inducing plasmid of Neurospora is an invertron and encodes DNA and RNA polymerases. Curr Genet 1991; 20:225-37. [PMID: 1934129 DOI: 10.1007/bf00326237] [Citation(s) in RCA: 84] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The nucleotide sequence of kalilo, a linear plasmid that induces senescence in Neurospora by integrating into the mitochondrial chromosome, reveals structural and genetic features germane to the unique properties of this element. Prominent features include: (1) very long perfect terminal inverted repeats of nucleotide sequences which are devoid of obvious genetic functions, but are unusually GC-rich near both ends of the linear DNA; (2) small imperfect palindromes that are situated at the termini of the plasmid and are cognate with the active sites for plasmid integration into mtDNA; (3) two large, non-overlapping open-reading frames, ORF-1 and ORF-2, which are located on opposite strands of the plasmid and potentially encode RNA and DNA polymerases, respectively, and (4) a set of imperfect palindromes that coincide with similar structures that have been detected at more or less identical locations in the nucleotide sequences of other linear mitochondrial plasmids. The nucleotide sequence does not reveal a distinct gene that codes for the protein that is attached to the ends of the plasmid. However, a 335-amino acid, cryptic, N-terminal domain of the putative DNA polymerase might function as the terminal protein. Although the plasmid has been co-purified with nuclei and mitochondria, its nucleotide composition and codon usage indicate that it is a mitochondrial genetic element.
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Affiliation(s)
- B S Chan
- Department of Microbiology, University of Guelph, Ontario, Canada
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Zhao LJ, Irie K, Trirawatanapong T, Nakano R, Nakashima A, Morimatsu M, Padmanabhan R. Synthesis of biologically active adenovirus preterminal protein in insect cells using a baculovirus vector. Gene 1991; 100:147-54. [PMID: 1905255 DOI: 10.1016/0378-1119(91)90360-n] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A DNA fragment encoding the polyhedrin promoter of Autographa californica multiple nuclear polyhedrosis virus (AcMNPV strain) was constructed using overlapping oligodeoxyribonucleotides (oligos), which included the 5'-untranslated leader sequence of the polyhedrin-encoding gene. This DNA fragment was cloned into an intermediate transfer vector (pKX105) providing a unique BamHI site for the insertion of foreign genes. The Escherichia coli lacZ gene was first cloned at the BamHI site of pKX105 and the XhoI-KpnI fragment containing the lacZ gene was transferred to another plasmid vector (pEI) consisting of flanking AcMNPV sequences (pEI-lacZ). The E. coli beta-galactosidase that was produced in the infected insect cells using the recombinant virus constituted about 10% of the total cytoplasmic proteins. The pKX105 plasmid was also modified to give rise to pTT-lacZ which consisted of the lacZ gene under the control of the Rous sarcoma virus long terminal repeat promoter to facilitate rapid screening of the baculoviral recombinants in which the gene of interest was cloned under the control of the polyhedrin promoter. The efficiency of these transfer vectors was verified by obtaining high levels of expression of the adenovirus(Ad)-encoded preterminal protein (pTP) which is involved as a protein primer in the initiation of Ad DNA replication. The baculovirus-produced pTP was immunoprecipitable using rabbit polyclonal antibodies raised against a hydrophilic domain of pTP. The pTP protein was localized in the nucleus of the infected insect cells, and was biologically active in the in vitro Ad type 2 (Ad2) replication initiation assay.
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Affiliation(s)
- L J Zhao
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City 66103
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11
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Roovers DJ, Overman PF, Chen XQ, Sussenbach JS. Linker mutation scanning of the genes encoding the adenovirus type 5 terminal protein precursor and DNA polymerase. Virology 1991; 180:273-84. [PMID: 1984653 DOI: 10.1016/0042-6822(91)90032-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The replication of adenovirus DNA requires, in addition to several host factors, three virus-encoded proteins: a DNA binding protein, the precursor of the terminal protein (pTP), and a DNA polymerase (Ad pol). Ad pol and pTP form a tight complex that is necessary for the initiation step in DNA replication. To perform mutation scanning of the adenovirus type 5 pTP and Ad pol a series of in-frame linker insertions of a 12-mer oligonucleotide d(CCCATCGATGGG) were introduced into cloned viral DNA fragments containing coding sequences of these proteins. The insertions are located at recognition sites for several blunt end-cutting restriction endonucleases. Forty different sites were mutagenized and the mutated genes were transferred to a plasmid that contains the left 42% of the adenovirus genome. They were rebuilt into the viral genome by means of in vivo recombination between plasmid DNA and digested adenovirus DNA-TP complex. The resulting viral genomes were tested for viability and rescued virus was analyzed for the presence of the inserted linker oligonucleotide. This procedure resulted in recovery of a number of viable virus mutants with insertions in the pTP or Ad pol genes, all of which are phenotypically silent. The other mutations did not allow virus production. The positions of these apparent lethal codon insertion mutations were useful to identify regions of functional importance in both proteins. It can be concluded that the precursor-specific region of pTP plays an important role in virus multiplication.
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Affiliation(s)
- D J Roovers
- Laboratory for Physiological Chemistry, State University of Utrecht, The Netherlands
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12
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Protein-protein interactions between adenovirus DNA polymerase and nuclear factor I mediate formation of the DNA replication preinitiation complex. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(17)44799-5] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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13
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Schaack J, Ho WY, Freimuth P, Shenk T. Adenovirus terminal protein mediates both nuclear matrix association and efficient transcription of adenovirus DNA. Genes Dev 1990; 4:1197-208. [PMID: 2210375 DOI: 10.1101/gad.4.7.1197] [Citation(s) in RCA: 120] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Adenovirus DNA is tightly bound to the nuclear matrix throughout the course of infection. Analysis of adenovirus DNA from infected HeLa cell nuclei after extraction with lithium diiodosalicylate and digestion with restriction enzymes demonstrated that the sites of tightest attachment occur in the terminal fragments of the linear viral chromosome. Analysis of viruses mutated in the precursor terminal protein coding sequence demonstrated that the terminal protein, which is covalently attached to the 5' end of each DNA strand, mediates the tight binding. Virions containing chromosomes with mutant terminal proteins were unpackaged and viral DNA accumulated in the nucleus at a normal rate and competed for the limiting component during transcription complex formation, but their early genes were transcribed at reduced efficiency by both RNA polymerases II and III. The transcriptional defects were not complemented by coinfection with a wild-type virus. We propose that the adenovirus chromosome may exist as a single chromatin domain during infection and that binding of DNA to the nuclear matrix may play a critical role in adenovirus transcription.
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Affiliation(s)
- J Schaack
- Howard Hughes Medical Institute, Department of Biology, Princeton University, New Jersey 08544
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Pettit SC, Horwitz MS, Engler JA. Mutations of the precursor to the terminal protein of adenovirus serotypes 2 and 5. J Virol 1989; 63:5244-50. [PMID: 2511338 PMCID: PMC251189 DOI: 10.1128/jvi.63.12.5244-5250.1989] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Using a series of transient expression plasmids and adenovirus-specific DNA replication assays for both initiation and elongation, we measured the relative activities of mutant polypeptides of the precursor to the terminal protein (pTP) in vitro. Mutations that removed two to six amino acids of the amino terminus gradually decreased pTP activity; a deletion of 18 amino acids was completely inactive. Replacement of cysteine at residue 8 with a serine had little effect on pTP activity. Two amino-terminal in-frame linker insertion mutant polypeptides previously characterized in vivo as either replication defective or temperature sensitive had considerable activity at the permissive temperature in vitro. For one mutant pTP with a temperature-sensitive phenotype in vivo, elongation activity was decreased more than initiation in vitro, suggesting a role for this protein after the initiation step. Replacement mutations of serine 580, the site of covalent attachment of dCTP, completely abolished pTP function for both initiation and elongation.
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Affiliation(s)
- S C Pettit
- Department of Biochemistry, University of Alabama, Birmingham, University Station 35294
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15
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Affiliation(s)
- R T Hay
- Department of Biochemistry and Microbiology, University of St. Andrews, Fife, U.K
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16
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Zhao LJ, Padmanabhan R. Nuclear transport of adenovirus DNA polymerase is facilitated by interaction with preterminal protein. Cell 1988; 55:1005-15. [PMID: 3203379 DOI: 10.1016/0092-8674(88)90245-0] [Citation(s) in RCA: 138] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The mRNAs for the 80 kd adenovirus preterminal protein (pTP) and the 140 kd DNA polymerase (AdPol) contain several exons spliced to the main open reading frames (m-ORFs) located in the early transcription unit E2B. These proteins were transiently expressed in monkey kidney cells (CV1) utilizing the first ATG (pTP1 and AdPol1) or the ATG of a linker inserted at the beginning of the m-ORFs (pTP2 and AdPol2). Only pTP2 and AdPol2 were functionally active in an in vitro replication initiation assay. Both pTP1 and pTP2 were transported to the nucleus. The sequence RLPV(R)6VP, which is present in both pTPs, is identified as their nuclear localization signal. In contrast, AdPol1 was cytoplasmically localized, whereas AdPol2 was distributed in both compartments, suggesting that the nuclear localization signal for AdPol is within the first 139 amino acids. Interestingly, when AdPol1 and pTP1 or AdPol2 and pTP2 were coexpressed in the transfected cells, the nuclear distribution of AdPol1 or AdPol2 was significantly increased. We demonstrate that the nuclear transport of AdPol is facilitated, irrespective of the presence of its nuclear localization signal, by interaction with pTP.
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Affiliation(s)
- L J Zhao
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City 66103
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Shu L, Pettit SC, Engler JA. The precise structure and coding capacity of mRNAs from early region 2B of human adenovirus serotype 2. Virology 1988; 165:348-56. [PMID: 3407147 DOI: 10.1016/0042-6822(88)90579-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Replication of human adenovirus (Ad) DNA requires three virus-encoded proteins that are coordinately transcribed from a single promoter at early times after infection. The mRNAs for two of these proteins, the precursor to the terminal protein (pTP) and the Ad DNA polymerase (Ad Pol), share several exons, including one encoded near Ad genome coordinate 39. The positions of the splice points of these mRNAs have been mapped by S1 nuclease mapping, by RNA sequencing, and by cDNA cloning. As a result of RNA splicing events, a short open reading frame (ORF) encoded at genome coordinate 39 is connected to the beginning of both the pTP and Ad Pol coding sequences; inclusion of this upstream ORF is essential for expression of functional pTP and Ad Pol proteins.
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Affiliation(s)
- L Shu
- Department of Biochemistry, University of Alabama, Birmingham 35294
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