Robert J. Geraghty, PhD

Anti-Viral Drug Discovery

Our main interests are identifying anti-viral drug targets for major human pathogens and evaluating small molecules for their ability to inhibit those targets and virus replication. We employ three main approaches to uncover small molecules that inhibit the replication and pathogenesis of viruses: (1) Conduct phenotypic screens to evaluate anti-viral activity of small molecules. (2) Collaborate with medicinal chemists, computational chemists and structural biologists to rationally design small molecule inhibitors of established and novel viral drug targets. (3) Design and implement high throughput screening to identify small molecules that inhibit known and novel viral drug targets.

Investigation of Aspects of Virus Replication

We are investigating aspects of virus replication for the following viruses - For the Flaviviruses hepatitis C virus and West Nile virus as well as the Orthomyxovirus influenza A virus, we have active projects to identify inhibitors of the respective viral polymerases. We are also interested in identifying inhibitors of cellular factors that those viruses must use to replicate. We are currently studying two Herpesviruses, herpes simplex virus (HSV) and cytomegalovirus (CMV). We have a long-standing interest in understanding the molecular details of HSV entry into cells. We are interested in the entire process of virus entry including binding to cells, fusion of the viral membrane with cell membranes either at the plasma membrane or in an endocytic vesicle, and the role of pH in the entry/fusion process. We continue to study the expression of the major viral surface proteins, their incorporation onto virus particles, and their roles in cell binding and membrane fusion. The ultimate goal of these studies is to identify steps in virus entry that are most susceptible to inhibition using small molecules such as organic compounds or small proteins/peptides. The beta herpesvirus CMV is a major pathogen for neonates and the immune compromised. We are taking a target-based approach to interrogate viral enzymes with known and novel chemotypes to identify inhibitors. The viral enzyme inhibitors identified are then screened for their ability to inhibit virus replication in cell culture.

Other interests

We have collaborative projects looking at novel targets and anti-virals for human immunodeficiency virus and also to understand the entry of coronaviruses into cells.

7/1/96 – 6/30/99: F32 AI09471.Individual National Research Support Award. Department of Health and Human Services, National Institute of Health. Protein Interactions In Herpesvirus Cell Fusion.

01/01/02 – 12/31/02 American Cancer Society
Institutional Research Grant
Cellular Factors In Cell-To-Cell Spread Of Herpesviruses, Principal Investigator, $20,000 direct costs.
Role: PI

9/30/02 – 2/28/08
R01 AI051476 NIH/NIAID
Spread Of HSV-1 Mediated By The gD Receptor Nectin-1. National Institute of Health. National Institute of Allergy and Infectious Diseases.
Role: PI

5/15/09 – 5/14/12
RO3 AI078079 NIH/NIAID
Membrane fusion during HSV-1 entry.
Role: PI

6/1/10 – 5/31/15
R01 AI089728 NIH/NIAID
Receptor recognition mechanisms of coronaviruses.
Role: Co-Investigator (Dr. Fang Li Principal Investigator)

7/1/12 – 6/30/14
Center for Drug Design Research Development and Seed Grant
Identification Of Inhibitors Of HCMV UL89 Terminase And HCMV Replication
Role: PI

7/1/14 – 6/30/18
Center for Drug Design Research Development and Seed Grant
Viral Endonucleases.
Role: PI

9/1/16 – 8/31/18
University of Minnesota AHC Faculty Research Development Grant Program
Development of biological and structural approaches to Zika virus drug discovery
Role: PI

1/25/19-12/31/24
R01 AI136982-01 NIH/NIAID
Discovery and development of novel anti-HCMV agents targeting the UL89 terminase protein
Role: Co-PI (Zhengqiang Wang Co-PI)

• Wang, Z.; Geraghty, R. J.; Vince, R.; Tang, J. (University of Minnesota, USA). N-Hydroxypyrimidine-2,4-diones as inhibitors of HIV and HCV and their preparation. Application: WO 20111005.; SciFinder Scholar 2012:533369.
• Spear, P.G., Geraghty, R.J., Martinez, W.M., Montgomery, R.I., Warner, M.S., Cohen, G.H., Eisenberg, R.J., Whitbeck, C.J., and Krummenacher, C. Cellular Proteins Which Mediate Herpesvirus Entry, U.S. Patent # 6,641,818. 2000.

• Wang Y., and Geraghty R.J., (2019) FRET-based assay using a three-way junction DNA substrate to identify inhibitors of human cytomegalovirus pUL89 endonuclease activity. Eur. J. Pharm. Sci. 2019; 127:29-37.
• Kankanala J., Wang Y., Geraghty R.J., and Wang Z., (2018) Hydroxypyridonecarboxylic Acids as Inhibitors of Human Cytomegalovirus pUL89 Endonuclease. ChemMedChem 13(16):1658-1663.
• Wang, Y., Tang, J., Wang, Z., and Geraghty, R.J., (2018) Metal-chelating 3-hydroxypyrimidine-2,4-diones inhibit human cytomegalovirus pUL89 endonuclease activity and virus replication. Antiviral Res. 152:10-17.
• Qiu, L., Patterson, S.E., Bonnac, L.F.*,and Geraghty, R.J.*, (2018) Nucleobases and corresponding nucleosides display potent antiviral activities against dengue virus, possibly through viral lethal mutagenesis. PLoS Neglected Trop. Dis. 12(4): e30006421. *Denotes co-contributing authors
• Zhou, W., Wang, Y., Xie, J. and Geraghty, R.J., (2017) A Fluorescence-Based High-Throughput Assay to Identify Inhibitors of Tyrosylprotein Sulfotransferase Activity. Biochemistry and Biophysics Research Communications 482:1207-1212.
• Wang, Y., Mao, L., Kankanala, J., Wang, Z.,and Geraghty, R. J., (2017) Inhibition of Human Cytomegalovirus pUL89 Terminase Subunit Blocks Virus Replication and Genome Cleavage. Journal of Virology 91(3): e02152-16.
• Ai, T.; Xu, Y.; Qiu, L.; Geraghty, R. J.; Chen, L. Hydroxamic acids block replication of hepatitis C virus. J. Med. Chem. 2015, 58, 785-800. PubMed PMID: 25490700.
• Vernekar, S. K.; Qiu, L.; Zhang, J.; Kankanala, J.; Li, H.; Geraghty, R. J.; Wang, Z. 5'-Silylated 3'-1,2,3-triazolyl Thymidine Analogues as Inhibitors of West Nile Virus and Dengue Virus. J. Med. Chem. 2015, 58, 4016-4028. NIHMSID: NIHMS695073. PubMed PMID: 25909386 PMCID: PMC4465584.
• Ai, T.; Qiu, L.; Xie, J.; Geraghty, R. J.; Chen, L. Design and synthesis of an activity-based protein profiling probe derived from cinnamic hydroxamic acid. Bioorg. Med. Chem. 2016, 24, 686-692. PubMed PMID: 26753813
• Zhou, W.; Duckworth, B. P.; Geraghty, R. J. Fluorescent peptide sensors for tyrosylprotein sulfotransferase activity. Anal. Biochem. 2014, 461, 1-6.
• Vernekar, S. K. V.; Qiu, L.; Zacharias, J.; Geraghty, R. J.; Wang, Z. Synthesis and antiviral evaluation of 4’-(1,2,3-triazol-1-yl)thymidines. Med. Chem. Commun. 2014, 5, 603-608.
• Zhou, W.; Chen, F.; Klyachkin, Y.; Sham, Y. Y.; Geraghty, R. J.; Mutations in the amino terminus of herpes simplex virus type 1 gL can reduce cell-cell fusion without affecting gH/gL trafficking. J. Virol. 2013, 88, 739-744.
• Wu, K.; Peng, G.; Wilken, M.; Geraghty, R. J.; Li, F. Mechanisms of host receptor adaptation by severe acute respiratory syndrome coronavirus. J. Biol. Chem. 2012, 287, 8904-8911.
• Chen, Y.-L.; Zacharias, J.; Vince, R.; Geraghty, R. J.; Wang, Z. C-6 Aryl substituted 4-quinolone-3-carboxylic acids as inhibitors of hepatitis C virus. Bioorg. Med. Chem. 2012, 20, 4790-4800.
• Chen, Y.-L.; Tang, J.; Kesler, M. J.; Sham, Y. Y.; Vince, R.; Geraghty, R. J.; Wang, Z. The design, synthesis and biological evaluations of C-6 or C-7 substituted 2-hydroxyisoquinoline-1,3-diones as inhibitors of hepatitis C virus. Bioorg. Med. Chem. 2012, 20, 467-479.
• Wu, K.; Chen, L.; Peng, G.; Zhou, W.; Pennell, C. A.; Mansky, L. M.; Geraghty, R. J.; Li, F. A virus-binding hot spot on human angiotensin-converting enzyme 2 is critical for binding of two different coronaviruses. J. Virol. 2011, 85, 5331-5337.
• Klyachkin, Y. M.; Geraghty, R. J. Mutagenic analysis of herpes simplex virus type 1 glycoprotein L reveals the importance of an arginine-rich region for function. Virology 2008, 374, 23-32.
• Subramanian, R. P.; Geraghty, R. J. Herpes simplex virus type 1 mediates fusion through a hemifusion intermediate by sequential activity of glycoproteins D, H, L, and B. Proc. Natl. Acad. Sci. U. S. A. 2007, 104, 2903-2908.
• Klyachkin, Y. M.; Stoops, K. D.; Geraghty, R. J. Herpes simplex virus type 1 glycoprotein L mutants that fail to promote trafficking of glycoprotein H and fail to function in fusion can induce binding of glycoprotein L-dependent anti-glycoprotein H antibodies. J. Gen. Virol. 2006, 87, 759-767.
• Even, D. L.; Henley, A. M.; Geraghty, R. J. The requirements for herpes simplex virus type 1 cell-cell spread via nectin-1 parallel those for virus entry. Virus Res. 2006, 119, 195-207.
• Subramanian, R. P.; Dunn, J. E.; Geraghty, R. J. The nectin-1? transmembrane domain, but not the cytoplasmic tail, influences cell fusion induced by HSV-1 glycoproteins. Virology 2005, 339, 176-191.
• Jones, N. A.; Geraghty, R. J. Fusion activity of lipid-anchored envelope glycoproteins of herpes simplex virus type 1. Virology 2004, 324, 213-228.
• Terry-Allison, T.; Montgomery, R. I.; Warner, M. S.; Geraghty, R. J.; Spear, P. G. Contributions of gD receptors and glycosaminoglycan sulfation to cell fusion mediated by herpes simplex virus 1. Virus Res. 2001, 74, 39-45.
• Geraghty, R. J.; Fridberg, A.; Krummenacher, C.; Cohen, G. H.; Eisenberg, R. J.; Spear, P. G. Use of chimeric nectin-1(HveC)-related receptors to demonstrate that ability to bind alphaherpesvirus gD is not necessarily sufficient for viral entry. Virology 2001, 285, 366-375.
• Baury, B.; Geraghty, R. J.; Masson, D.; Lustenberger, P.; Spear, P. G.; Denis, M. G. Organization of the rat Tage4 gene and herpesvirus entry activity of the encoded protein. Gene 2001, 265, 185-194.
• Geraghty, R. J.; Jogger, C. R.; Spear, P. G. Cellular expression of alphaherpesvirus gD interferes with entry of homologous and heterologous alphaherpesviruses by blocking access to a shared gD receptor. Virology 2000, 268, 147-158.
• Krummenacher, C.; Rux, A. H.; Whitbeck, J. C.; Ponce-De-Leon, M.; Lou, H.; Baribaud, I.; Hou, W.; Zou, C.; Geraghty, R. J.; Spear, P. G.; Eisenberg, R. J.; Cohen, G. H. The first immunoglobulin-like domain of HveC is sufficient to bind herpes simplex virus gD with full affinity, while the third domain is involved in oligomerization of HveC. J. Virol. 1999, 73, 8127-8137.
• Warner, M. S.; Geraghty, R. J.; Martinez, W. M.; Montgomery, R. I.; Whitbeck, C.; Xu, R.; Eisenberg, R. J.; Cohen, G. H.; Spear, P. G. A cell surface protein with herpesvirus entry activity (HveB) confers susceptibility to infection by mutants of herpes simplex virus type 1, herpes simplex virus type 2, and pseudorabies virus. Virology 1998, 246, 179-189.
• Krummenacher, C.; Nicola, A. V.; Whitbeck, J. C.; Lou, H.; Hou, W.; Lambris, J. D.; Geraghty, R. J.; Spear, P. G.; Cohen, G. H.; Eisenberg, R. J. Herpes simplex virus glycoprotein D can bind to poliovirus receptor-related protein 1 or herpesvirus entry mediator, two structurally unrelated mediators of virus entry. J. Virol. 1998, 72, 7064-7074.
• Geraghty, R. J.; Krummenacher, C.; Cohen, G. H.; Eisenberg, R. J.; Spear, P. G. Entry of alphaherpesviruses mediated by poliovirus receptor-related protein 1 and poliovirus receptor. Science 1998, 280, 1618-1620.
• Schwartz, M. D.; Geraghty, R. J.; Panganiban, A. T. HIV-1 particle release mediated by Vpu is distinct from that mediated by p6. Virology 1996, 224, 302-309.
• Geraghty, R. J.; Talbot, K. J.; Callahan, M.; Harper, W.; Panganiban, A. T. Cell type-dependence for Vpu function. J. Med. Primatol. 1994, 23, 146-150.
• Geraghty, R. J.; Panganiban, A. T. Human immunodeficiency virus type 1 Vpu has a CD4- and an envelope glycoprotein-independent function. J. Virol. 1993, 67, 4190-4194.