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Physical state of human papillomavirus type 16 in cervical cell DNA

100%

Szostek S., Klimek M., Zawilinska B., Kosz-Vnenchak M.

Folia Biologica

2008

tom 56

nr 3-4

269-271

The HPV16 E2 transcriptional regulator mode of action depends on the physical state of the viral genome

84%

Schmidt M. T., Olejnik A. K., Gozdzicka-Jozefiak A.

Acta Biochimica Polonica

2005

tom 52

nr 4

Human papillomavirus (HPV) infection is a major risk factor for the development of cervical cancer. The HPV-induced immortalization of epithelial cell usually requires integration of the viral DNA into the host cell genome. The integration event causes disruption of the E2 gene and this is followed by overexpression of the E6 and E7 oncoproteins. The E2 protein is a transcription factor that regulates expression of the E6 and E7 oncoproteins by binding to four sites within the viral long control region. We used an in vitro cell culture model to explore the role of the E2 protein in the transcriptional control of the HPV16 long control region. Employing transient and stable transfection experiments we simulated the episomal and integrated states of the viral genome, respectively. We show that the E2 protein up-regulates E6/E7 transcription from episomal DNA but represses it in the case of integrated DNA. The activator function of the E2 protein seems to counteract the repressive chromatin structure formed over episomal DNA. Steroid hormones and retinol also modulate oncogene transcription differently depending on the physical structure of the viral DNA. Our data suggest regulatory mechanisms involving interactions between the E2 protein and nuclear hormone receptors.

Expression of Bombyx mori nucleopolyhedrovirus ORF76 in permissive and non-permissive cell lines by a novel Bac-to-Bac-BmNPV baculovirus expression system

67%

Su W. J., Wu Y., Wu H.-L., Zhu S.-Y., Wang W.-B.

Polish Journal of Microbiology

2008

tom 57

nr 4

Open reading frame 76 of Bombyx mori nucleopolyhedrovirus (BmNPV), designated as Bm76, is a gene whose function is completely unknown. With EGFP fused to the 3' terminal of Bm76 as the reporter gene and BmNPV bacmid as the expression vector, a recombinant bacmid was successfully constructed expressing Bm76-EGFP fusion protein under the control of polyhedrin promoter in Bombyx mori cells (Bm cells), BmNPV's permissive cell line, laying the foundation for rescue experiment of Bm76 deletion mutant. Moreover, the supernatant from Bm cells transfected with the recombinant bacmid was used to infect Trichoplusia Ni cells (Tn cells), BmNPV's non-permissive cell line. Unexpectedly, the expression of Bm76-EGFP fusion protein in some Tn cells was detected, implying that viral DNA was replicated in these cells. The causes are being studied for the inability of BmNPV to produce enough viable budded viruses in Tn cells despite of viral DNA replication.

Ograniczanie wyników

1 Acta Biochimica Polonica

1 Folia Biologica

1 Polish Journal of Microbiology

1 Gozdzicka-Jozefiak A.

1 Klimek M.

1 Kosz-Vnenchak M.

1 Olejnik A. K.

1 Schmidt M. T.

1 Su W. J.

1 Szostek S.

1 Wang W.-B.

1 Wu H.-L.

1 Wu Y.

1 Zawilinska B.

1 Zhu S.-Y.

2 2008

1 2005

Wyniki wyszukiwania

Physical state of human papillomavirus type 16 in cervical cell DNA

The HPV16 E2 transcriptional regulator mode of action depends on the physical state of the viral genome

Expression of Bombyx mori nucleopolyhedrovirus ORF76 in permissive and non-permissive cell lines by a novel Bac-to-Bac-BmNPV baculovirus expression system