DF/HCC Program Affiliation

Cancer Genetics
Cancer Cell Biology

Research Abstract

The Coen laboratory takes molecular approaches to herpesviruses, especially to understand processes that distinguish viral functions from cellular functions, which can be exploited to permit antiviral therapy. Although much of the research involves herpes simplex virus (HSV), which is not an oncogenic virus, many of the findings apply to oncogenic herpesviruses and to biological processes and drug discovery strategies relevant to cancer in general.

The foci of the laboratory are 1) regulation of expression of viral genes, 2) functional dissection of replication proteins, 3) analysis of virus latency, a fascinating and clinically important topic, 4) antiviral drug targets, drug mechanisms, and drug resistance. In the first area, we study novel post-transcriptional regulatory mechanisms in the HSV system, including ribosomal frameshifting on thymidine kinase mRNAs from drug-resistant mutants, antisense regulation, and regulated
polyadenylation. In the second area, we focus on herpesvirus DNA polymerases, which are both antiviral drug targets and prototypes for eukaryotic replicative polymerases. We use antiviral drug resistance to help dissect amino acid residues involved in the the different steps of polymerization; explore the interactions of polymerases with processivity proteins via mutational and biophysical approaches; and have been determining how the processivity factors function via a novel mechanism involving direct DNA binding. These studies should permit detailed
understanding of these complicated enzymes and rational drug design, particularly to interrupt protein-protein interactions.

In the third area, latency and pathogenesis, we use virus mutants and PCR-based methods to explore gene function and regulation (e.g. checkpoints for repressing gene expression) and the state of viral DNA during latency. We are also studying the interaction of HSV with the central nervous system with implications for the use of HSV-based therapies for nervous system diseases such as brain tumors. In the fourth area, antiviral drug targets, mechanisms, and resistance, aside from the studies mentioned above, we are exploiting the human cytomegalovirus protein
kinase that phosphorylates ganciclovir to aid the design of better antiviral drugs, and are finding new drug targets primarily by analyzing drug-resistant mutants.

Publications

• Pesola JM, Coen DM.In vivo fitness and virulence of a drug-resistant herpes simplex virus 1 mutant.J Gen Virol 2007 May;88(Pt 5):1410-4.
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• Jiang C, Hwang YT, Randell JC, Coen DM, Hwang CB.Mutations that decrease DNA binding of the processivity factor of the herpes simplex virus DNA polymerase reduce viral yield, alter the kinetics of viral DNA replication, and decrease the fidelity of DNA re
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• Griffiths A, Link MA, Furness CL, Coen DM.Low-level expression and reversion both contribute to reactivation of herpes simplex virus drug-resistant mutants with mutations on homopolymeric sequences in thymidine kinase.J Virol 2006 Jul;80(13):6568-74.
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• Cui C, Griffiths A, Li G, Silva LM, Kramer MF, Gaasterland T, Wang XJ, Coen DM.Prediction and identification of herpes simplex virus 1-encoded microRNAs.J Virol 2006 Jun;80(11):5499-508.
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• Chen SH, Kramer MF, Schaffer PA, Coen DM.A viral function represses accumulation of transcripts from productive-cycle genes in mouse ganglia latently infected with herpes simplex virus.J Virol 1997 Aug;71(8):5878-84.
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• Hume AJ, Finkel JS, Kamil JP, Coen DM, Culbertson MR, Kalejta RF.Phosphorylation of retinoblastoma protein by viral protein with cyclin-dependent kinase function.Science 2008 May 9;320(5877):797-9.
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• Komazin-Meredith G, Santos WL, Filman DJ, Hogle JM, Verdine GL, Coen DM.The positively charged surface of herpes simplex virus UL42 mediates DNA binding.J Biol Chem 2008 Mar 7;283(10):6154-61.
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• Bryant KF, Coen DM.Inhibition of translation by a short element in the 5' leader of the herpes simplex virus 1 DNA polymerase transcript.J Virol 2008 Jan;82(1):77-85.
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• Jiang C, Hwang YT, Wang G, Randell JC, Coen DM, Hwang CB.Herpes simplex virus mutants with multiple substitutions affecting DNA binding of UL42 are impaired for viral replication and DNA synthesis.J Virol 2007 Nov;81(21):12077-9.
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• Kamil JP, Coen DM.Human cytomegalovirus protein kinase UL97 forms a complex with the tegument phosphoprotein pp65.J Virol 2007 Oct;81(19):10659-68.
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• Loregian A, Sinigalia E, Mercorelli B, Palu G, Coen DM.Binding parameters and thermodynamics of the interaction of the human cytomegalovirus DNA polymerase accessory protein, UL44, with DNA: implications for the processivity mechanism.Nucleic Acids Res 20
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• Dodson AW, Taylor TJ, Knipe DM, Coen DM.Inhibitors of the sodium potassium ATPase that impair herpes simplex virus replication identified via a chemical screening approach.Virology 2007 Sep 30;366(2):340-8.
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• Besecker MI, Furness CL, Coen DM, Griffiths A.Expression of extremely low levels of thymidine kinase from an acyclovir-resistant herpes simplex virus mutant supports reactivation from latently infected mouse trigeminal ganglia.J Virol 2007 Aug;81(15):8356
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• Prichard MN, Gao N, Jairath S, Mulamba G, Krosky P, Coen DM, Parker BO, Pari GS.A recombinant human cytomegalovirus with a large deletion in UL97 has a severe replication deficiency.J Virol 1999 Jul;73(7):5663-70.
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• Huang L, Ishii KK, Zuccola H, Gehring AM, Hwang CB, Hogle J, Coen DM.The enzymological basis for resistance of herpesvirus DNA polymerase mutants to acyclovir: relationship to the structure of alpha-like DNA polymerases.Proc Natl Acad Sci U S A 1999 Jan 1
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• Weisshart K, Chow CS, Coen DM.Herpes simplex virus processivity factor UL42 imparts increased DNA-binding specificity to the viral DNA polymerase and decreased dissociation from primer-template without reducing the elongation rate.J Virol 1999 Jan;73(1):5
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• Burkham J, Coen DM, Weller SK.ND10 protein PML is recruited to herpes simplex virus type 1 prereplicative sites and replication compartments in the presence of viral DNA polymerase.J Virol 1998 Dec;72(12):10100-7.
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• Chen SH, Cook WJ, Grove KL, Coen DM.Human thymidine kinase can functionally replace herpes simplex virus type 1 thymidine kinase for viral replication in mouse sensory ganglia and reactivation from latency upon explant.J Virol 1998 Aug;72(8):6710-5.
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• Mulamba GB, Hu A, Azad RF, Anderson KP, Coen DM.Human cytomegalovirus mutant with sequence-dependent resistance to the phosphorothioate oligonucleotide fomivirsen (ISIS 2922).Antimicrob Agents Chemother 1998 Apr;42(4):971-3.
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• Jacobson JG, Chen SH, Cook WJ, Kramer MF, Coen DM.Importance of the herpes simplex virus UL24 gene for productive ganglionic infection in mice.Virology 1998 Mar 1;242(1):161-9.
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• Pelosi E, Mulamba GB, Coen DM.Penciclovir and pathogenesis phenotypes of drug-resistant Herpes simplex virus mutants.Antiviral Res 1998 Jan;37(1):17-28.
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• Kramer MF, Chen SH, Knipe DM, Coen DM.Accumulation of viral transcripts and DNA during establishment of latency by herpes simplex virus.J Virol 1998 Feb;72(2):1177-85.
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• Weisshart K, Kuo AA, Hwang CB, Kumura K, Coen DM.Structural and functional organization of herpes simplex virus DNA polymerase investigated by limited proteolysis.J Biol Chem 1994 Sep 9;269(36):22788-96.
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• Hwang CB, Horsburgh B, Pelosi E, Roberts S, Digard P, Coen DM.A net +1 frameshift permits synthesis of thymidine kinase from a drug-resistant herpes simplex virus mutant.Proc Natl Acad Sci U S A 1994 Jun 7;91(12):5461-5.
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• Davar G, Kramer MF, Garber D, Roca AL, Andersen JK, Bebrin W, Coen DM, Kosz-Vnenchak M, Knipe DM, Breakefield XO.Comparative efficacy of expression of genes delivered to mouse sensory neurons with herpes virus vectors.J Comp Neurol 1994 Jan 1;339(1):3-11.
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• Digard P, Chow CS, Pirrit L, Coen DM.Functional analysis of the herpes simplex virus UL42 protein.J Virol 1993 Mar;67(3):1159-68.
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• Weisshart K, Kuo AA, Painter GR, Wright LL, Furman PA, Coen DM.Conformational changes induced in herpes simplex virus DNA polymerase upon DNA binding.Proc Natl Acad Sci U S A 1993 Feb 1;90(3):1028-32.
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