The Functions of Human Papillomavirus Type 11 E1, E2, and E2C Proteins in Cell-free DNA Replication

Liu, Jen-Sing; Kuo, Shu-Ru; Broker, Thomas R.; Chow, Louise T.

doi:10.1074/jbc.270.45.27283

Cited by 76 publications

(98 citation statements)

References 53 publications

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“…Viral initiator proteins such as the simian virus 40 (SV40) large T antigen (T-Ag) and the papillomavirus E1 protein have long been known to melt their respective origins of DNA replication, as detected by oxidation with KMnO 4 (4,5,14,22,24,25). However, little information exists about which forms of these proteins execute melting, which parts of the polypeptide are responsible for the melting activity, and whether this process is DNA sequence dependent (5, 27).The E1 proteins from papillomaviruses are ϳ70-kDa polypeptides which, in addition to DNA melting activity, have DNA helicase activity (19,20,30,33,35,37,38,40) and also bind DNA. DNA binding by E1 is the result of two different DNA binding activities.…”

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confidence: 99%

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ATP-Dependent Minor Groove Recognition of TA Base Pairs Is Required for Template Melting by the E1 Initiator Protein

Schuck

Stenlund

2007

J Virol

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Template melting is an essential step in the initiation of DNA replication, but the mechanism of template melting is unknown for any replicon. Here we demonstrate that melting of the bovine papillomavirus type 1 ori is a sequence-dependent process which relies on specific recognition of TA base pairs in the minor groove by the E1 initiator. We show that correct template melting is a prerequisite for the formation of a stable double hexamer with helicase activity and that ori mutants that fail to melt correctly are defective for ori unwinding and DNA replication in vivo. Our results also indicate that melting of the DNA is achieved by destabilization of the double helix along its length through multiple interactions with E1, each of which is responsible for melting of a few base pairs, resulting in the extensive melting that is required for initiation of DNA replication.Template melting is an essential step in the initiation of replication of double-stranded DNA. In spite of its fundamental importance for DNA replication, the melting process is almost entirely uncharacterized. For Escherichia coli, the initiator DnaA has long been known to melt OriC, as can be detected by the use of single-stranded DNA (ssDNA)-specific nucleases (6, 32). The mechanism by which the DNA is melted is unknown, but it is established that melting is dependent on nucleotide binding by DnaA (for a review, see reference 16). For eukaryotes, although the origin recognition complex has been identified as the factor that marks the replicator (2), an activity that can melt the DNA in preparation for replication has still not been identified. Viral initiator proteins such as the simian virus 40 (SV40) large T antigen (T-Ag) and the papillomavirus E1 protein have long been known to melt their respective origins of DNA replication, as detected by oxidation with KMnO 4 (4,5,14,22,24,25). However, little information exists about which forms of these proteins execute melting, which parts of the polypeptide are responsible for the melting activity, and whether this process is DNA sequence dependent (5, 27).The E1 proteins from papillomaviruses are ϳ70-kDa polypeptides which, in addition to DNA melting activity, have DNA helicase activity (19,20,30,33,35,37,38,40) and also bind DNA. DNA binding by E1 is the result of two different DNA binding activities. Site-specific DNA binding is provided by the E1 DNA binding domain (DBD), which recognizes and binds to two pairs of E1 binding sites (E1 BS) in the origin of replication (7-9, 11, 15, 17, 31, 36). The E1 helicase domain binds DNA with low sequence specificity, and this activity is required for the ability of the E1 helicase domain to contact the DNA sequences flanking the E1 BS, including a region that has been termed the A/T-rich region (34).Recent advances in the study of E1 and T-Ag have opened up the melting process for more detailed study. Structural studies of E1 and T-Ag have provided important information about the domain structure, how these proteins oligomerize, and how they bind and hydro...

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mentioning

confidence: 99%

“…The E1 proteins from papillomaviruses are ϳ70-kDa polypeptides which, in addition to DNA melting activity, have DNA helicase activity (19,20,30,33,35,37,38,40) and also bind DNA. DNA binding by E1 is the result of two different DNA binding activities.…”

mentioning

confidence: 99%

ATP-Dependent Minor Groove Recognition of TA Base Pairs Is Required for Template Melting by the E1 Initiator Protein

Schuck

Stenlund

2007

J Virol

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“…The appearance of the hypersensitive sites might be the result of such a distortion. We have noticed that, similar to BPV-1 and HPV-11, the E1 protein of HPV-33 binds the ori with fairly low specificity (data not shown) (Sedman & Stenlund, 1995 ;Liu et al, 1995).…”

Section: (Data Not Shown) Since Nucleotides Within and Outside The Amentioning

confidence: 99%

Characterization of the DNA-binding activity of the E1 and E2 proteins and the E1/E2 complex of human papillomavirus type 33.

Möller¹,

Giroglou²,

Sapp³

1997

Journal of General Virology

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The E1 and E2 proteins of papillomaviruses are essential for the initiation of viral DNA replication. We have purified the E2 protein of human papillomavirus type 33 (HPV-33) by immunoaffinity chromatography. The purified E2 protein bound with high affinity to all four consensus binding sites of HPV-33 (K d % 2i10 N 10 M). A putative E2 binding site differing at one position in the second stem of the palindrome was not bound by E2. The E1 protein of HPV-33 purified by affinity chromatography using glutathione S-transferase as tag displayed specific DNA-binding activity in footprint analyses protecting HPV-33 nucleotides 7896 to 7909/1 to 18 from DNaseI digestion. Hypersensitive sites at position 6 on the sense and position 1 on the antisense strand were observed in the middle of the protected region. An E1/E2 complex protected the E1 binding site and E2 binding sites from DNaseI digestion suggesting that both proteins retain DNA-binding activity in the complex.Papillomaviruses (PV) comprise a heterogeneous group of small double-stranded DNA viruses infecting the basal layer of epithelia. They are associated with benign or malignant hyperproliferations which have a wide variety of clinical manifestations. The E1 and E2 proteins of PV have been shown to be essential for papillomaviral DNA replication by genetic studies (Lusky & Botchan, 1985), by transient replication assays (Ustav & Stenlund, 1991) and by the establishment of cell-free replication assays (Yang et al., 1991). The E1 protein contains an intrinsic NTPase, a DNA helicase and a DNAbinding activity (Seo et al., 1993). The E2 protein was initially identified as a transcriptional modulator. It binds with high affinity to a consensus sequence, ACC(N) ' GGT, which is found several times in the long control region (LCR) of all PV (Hawley Nelson et al., 1988). The E1 and E2 proteins interact in solution to form heteromeric complexes (Mohr et al., 1990). Author for correspondence : Martin Sapp.Fax j49 6131 392359. e-mail sapp!goofy.zdv.uni-mainz.deThe complex is able to interact with DNA and was shown to be essential for supporting DNA replication (Sedman & Stenlund, 1995). The requirements of cis-and trans-factors for 3) and eluate from the immunoaffinity chromatography (lanes 2 and 4) were analysed by SDS-PAGE followed by Coomassie blue staining (lanes 1 and 2) and by Western blot (lanes 3 and 4), respectively, using MAb 33E2-Ste3 as primary antibody. Bound antibodies were visualized with horseradish peroxidase coupled to rabbit anti-mouse IgG (Jackson Immunochemicals) followed by enhanced chemiluminescence (ECL, Amersham). The molecular masses of marker proteins are indicated on the left in kDa. (B) Increasing amounts of purified E2 were added to a fixed amount of a labelled oligonucleotide containing E2BS3 (5 fmol), incubated on ice and analysed by EMSA. The polyacrylamide gel was dried and exposed to X-ray film. Lanes 1 to 13, 0n19, 0n37, 0n74, 1n48, 2n97, 5n9, 11n9, 23n7, 47n5, 95, 190, 380 and 760 fmol of E2 dimer, respectively ; lane 14, 15n2 pmo...

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“…HPV transcription exhibits stringent cell specificity and the lack of regulated gene expression of viral early proteins from HPV genomes could be the reason that restricts HPV genome replication to certain cell types. BPV1 DNA replication in vitro with purified proteins and cell extracts from murine, simian and human cells has been reconstituted showing that all cellular factors essential for papillomavirus DNA replication are provided by the host cell (Liu et al, 1995;Muller et al, 1994;Yang et al, 1991a). The cellular replication factors required for papillomavirus DNA replication include replication protein A (RPA), a single-stranded-DNA-binding protein, replication factor C (RFC), proliferating-cell nuclear antigen (PCNA) and DNA polymerase -primase.…”

Section: Initiation Of Replicationmentioning

confidence: 99%

The Role of E2 Proteins in Papillomavirus DNA Replication

Kurg¹

2011

DNA Replication-Current Advances

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The Functions of Human Papillomavirus Type 11 E1, E2, and E2C Proteins in Cell-free DNA Replication

Cited by 76 publications

References 53 publications

ATP-Dependent Minor Groove Recognition of TA Base Pairs Is Required for Template Melting by the E1 Initiator Protein

ATP-Dependent Minor Groove Recognition of TA Base Pairs Is Required for Template Melting by the E1 Initiator Protein

Characterization of the DNA-binding activity of the E1 and E2 proteins and the E1/E2 complex of human papillomavirus type 33.

The Role of E2 Proteins in Papillomavirus DNA Replication

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