Last Updated: 3/29/2010

Joseph S. Pagano, M.D. Professor Virology

Research Interests
The Epstein-Barr Virus (EBV) is associated with malignancies of lymphocytic and epithelial origin. EBV produces different infection states, cytolytic and latent, as well as cell immortalization, all of which are captured in cell lines, making the different states accessible to mechanistic studies. Recently we have access to a humanized mouse model (see Lishan Su, http://unclineberger.org) for EBV infection and transformation studies. Currently our research deals with viral latency, functions of the EBV protein kinase and deubiquitinating enzymes in EBV systems, interferon regulatory factors (IRFs), invasion and metastasis induced by the EBV oncoprotein LMP1, and antiviral drugs.

In EBV's cytolytic infection cycle we are focusing on two EBV gene products. One encodes EBV's sole protein kinase which phosphorylates at least 20 EBV proteins, including the EBV DNA polymerase processivity factor used in viral replication, viral maturation proteins involved in egress of viral nucleocapids from the nucleus, and the R1 subunit of the EBV ribonucleotide reductase (RR). The other gene encodes the EBV deubiquitinating enzyme (DUB), which down-regulates function of the EBV RR, the first target identified for herpesvirus DUBs.

We also study mechanisms of cell immortalization and oncogenesis through EBV's ability to stabilize and activate β-catenin via the ubiquitin system with the focus on the cellular deubiquitinating enzyme, UCH L1. This DUB is induced by the master transcriptional transactivator, EBNA2, in EBV-transformed cells. Recently we discovered that UCH L1 is expressed in association with the mitotic spindle and regulates microtubule dynamics in diverse transformed cells.

IRF7 was discovered in this laboratory. How EBV is able to mount and evade IRF7-mediated immune responses, and the ability of EBV LMP1 to induce and activate IRF7, now recognized as the master regulator of type I interferon responses, through ubiquitination remain principal focuses.

Finally we hold that EBV, in addition to being an etiologic agent for its associated malignancies, may also serve to promote tumor progression. EBV’s major oncoprotein LMP1 can induce epithelial-mesenchymal transition (EMT) and promote cell migration through up-regulation of invasion, metastasis and angiogenic factors in NPC, as shown recently with Twist and Snail transcription factors and through phosphorylation of the ERM family member, Ezrin.


All trainees are encouraged to broaden their experience by also participating in the well known UNC-LCCC Postdoctoral Training Program, now in its 35th year, to assist in reaching their career goals. Fellows in my laboratory also present work in progress at the weekly meetings of the Virology Faculty at UNC.

Recent Accomplishments and Honors
Recent discoveries:

•The neuronal protein UCH L1 is aberrantly expressed in a variety of carcinomas and lymphomas. We have discovered a fundamental function for this ubiquitin-editing enzyme: its deubiquitinating and ubiquitin ligase activities are associated with tubulin throughout mitosis and affect its polymerization.

•LMP1, the principal oncoprotein of EBV, activates IRF7 through a RIP- and TRAF6-dependent ubiquitination pathway.

•A tumor virus, EBV, can activate the β-catenin signaling pathway in human lymphocytes through a novel mechanism, induction of the deubiquitinating enzyme UCH L1.

• IRF-7 has oncogenic properties that may potentiate those of LMP-1.

•Twist, a transcriptional factor essential for breast cancer metastasis and epithelial-mesenchymal transition, is detected with LMP1 in nasopharyngeal carcinoma.

•Phosphorylation of Ezrin, a member of the ERM family that links plasma membrane and the actin cytoskeleton and drives cell immigration, is induced by LMP1 and detected in nasopharyngeal carcinoma.

•The antiviral drug Maribavir in contrast to Acyclovir inhibits not only viral replication but viral transcription.

Honors:

2004 Fellow, American Association for the Advancement of Science
2009- Member, Science Advisory Board, US Food & Drug Administration

Publications
Selected Recent Publications:

Bheda A, Gullapalli A, Caplow M, Pagano JS, Shackelford J. Ubiquitin editing enzyme UCH L1 and microtubule dynamics: Implication in mitosis. Cell Cycle, 2010 Mar 15;9(5). [Featured on Journal Cover]. PMID: 20160478

Bentz G*. Liu R*, Hahn A, Shackelford J, Pagano JS. Epstein-Barr virus immediate-early protein RTA negatively regulates interferon regulatory factors. Virology (In press) 2010

Fu-Zhang Wang , Debasmita Roy, Edward Gershburg, Christopher Whitehurst, Dirk Dittmer, and Joseph S. Pagano. Maribavir inhibits Epstein-Barr viral transcription in addition to viral DNA replication. J Virol 2009 Dec;83(23):12108-17. PMCID: 2786727

Anjali Bheda, Julia Shackelford, and Joseph S. Pagano. Expression and functional studies of ubiquitin C-terminal hydrolase L1 regulated genes. PLoSONE 2009.
4(8): e6764. PMCID: 2729380

Anjali Bheda, Wei Yue, Anuradha Gullapalli, Chris Whitehurst, Renshui Liu, Joseph S. Pagano, and Julia Shackelford. Positive reciprocal regulation of ubiquitin C-terminal hydrolase L1 and beta-catenin/TCF signaling. PLoS ONE 2009. 4(6): e5955.
PMCID: 2694282

K Endo, S Kondo, J Shackleford, T Horikawa, N Kitagawa, T Yoshizaki. Phosphorylated ezrin is associated with EBV latent membrane protein 1 in nasopharyngeal carcinoma and induces cell migration. Oncogene 2009
Apr 9;28(14):1725-35. PMID: 19234486

Christopher Whitehurst, Shunbin Ning, Gretchen L. Bentz, Florent Dufour, Edward Gershburg, Julia Shackelford, Yves Langelier, and Joseph S. Pagano. The EBV deubiquitinating Enzyme, BPLF1, reduces EBV ribonucleotide reductase activity. J irol. 2009 May;83(9):4345-53. PMCID: 2668490

Pagano, J.S. EBV Diseases. 2009. Chapter 10, in DNA Tumor Viruses. Edited by B. Damania and J. M. Pipas, pp 217-240, Springer

Shunbin Ning, Alex Campos, Bryant Darnay, Gretchen Bentz, Joseph Pagano
TRAF6 and the three C-terminal lysine sites on IRF7 are required for its activation by the TNFR family member LMP1. Mol Cell Biol. 2008. 28(20): 6536-6546. PMCID: 2577435

Gershburg E, Pagano, JS. Conserved herpesvirus protein kinases. Biochim Biophys Acta. 2008. 1784(1):203-12. PMCID: 2265104

Gershburg, E., Raffa, S., Torrisi, MR. and. Pagano, JS. Epstein-Barr virus-encoded protein kinase (BGLF4) is involved in production of infectious virus. J Virol. 2007. PMCID: PMC1900237

Huye, L.*, Ning, S.*, Kelliher, M., Pagano, J. IRF7 is activated by a viral oncoprotein through RIP-dependent ubiquitination. Mol Cell Biol. 2007. 27(8): 2910-2918. PMCID: 1899925

Horikawa T, Yang J, Kondo S, Yoshizaki T, Joab I, Furukawa M, Pagano JS.
Twist and Epithelial-Mesenchymal Transition are Induced by the Epstein-Barr Virus Oncoprotein Latent Membrane Protein 1 and are Associated with Metastatic Nasopharyngeal Carcinoma. Cancer Res. 2007. 67(5): 1970-1978. PMID: 17332324

Kondo S, Seo SY, Yoshizaki T, Wakisaka N, Furukawa M, Joab I, Jang KL, Pagano JS. EBV latent membrane protein 1 up-regulates hypoxia-inducible factor 1α through Siah1-mediated down-regulation of prolyl hydroxylases 1 and 3 in nasopharyngeal epithelial cells. Cancer Res. 2006 Oct 15;66(20):9870-7.
PMID: 17047048

Yue, W., Shackelford, J., Pagano, JS. Cdc2/cyclin B1-dependent phosphorylation of EBNA2 at Ser243 regulates its function in mitosis. J Virol. 2006 Feb; 80(4):2045-50. PMCID: 1367142

Jang, KL., Shackelford, J., Seo SY, Pagano, JS. Up-regulation of beta-catenin by a viral oncogene correlates with inhibition of Siah-1 ubiquitin ligase in B-lymphoma cells. Proc Natl Acad Sci U S A. 2005, 02(51):18431-6. PMCID: 1317901

Yue, W., Gershburg, E., Pagano, J.S. Epstein-Barr Virus protein kinase phosphorylates EBNA2 and suppresses EBNA2 transactivation of the LMP1 promoter. J. Virol. 2005. 79(9): 5880-5885. PMCID: 1082719

Shackelford J., Pagano JS. Targeting of host-cell ubiquitin pathways by viruses.
In Essays in Biochemistry, 2005 41: 139-156. Portland Press Ltd. London, UK.
PMID: 16250903

Yoshizaki, T., Wakisaka, N. and Pagano, J.S. Epstein-Barr Virus invasion and metastasis. 2005. Chapter 12. in: Epstein-Barr Virus. Ed. by E. Robertson. Caister Academic, Norfolk, England. 171-196.

E-mail: joseph_pagano@med.unc.edu
Telephone: (919) 966-8644 / 919-966-5907
FAX: (919) 966-9673
Address: 32-000 Lineberger, CB# 7295 Chapel Hill, NC
URL: paganolab.net

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