[2017 Spring Life Sciences & IBB Seminar]

▶Subject: Ubiquitin and ISG15 in antiviral immunity and herpesvirus regulation

▶Speaker: Prof. Jin-Hyun Ahn (Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine)

▶Date: 5:15PM/May. 19(Fri.)/2017

▶Place: Auditorium(1F), Postech Biotech Center

▶Abctract
Ubiquitin and ubiquitin-like proteins are involved in antiviral immunity and viruses interact with them in a variety of ways. Viral proteins are often a substrate for modification, which leads to proteasomal degradation or alteration of protein functions. Viruses may have functions to modify these cellular modification machineries. Deubiquitinating protease (DUB) activity has been found in many viral proteins. We found that the human cytomegalovirus (HCMV)-encoded DUB inhibits NF-κB signaling by modulating ubiquitination of receptor-interacting protein kinase 1 (RIP1) and that this activity is necessary for efficient viral replication. The viral DUBs seem to primarily target cellular regulators of innate immune signaling or inflammation to promote viral replication. The additional roles of the viral DUB in the viral replication cycle will be discussed. Interferon-stimulated gene (ISG) 15 encodes an ubiquitin-like protein that inhibits the replication of many viruses. We found that in HCMV infection ISG15 induction is largely mitigated by a viral inhibitor of interferon signaling that targets to STAT2 and PML, but ISGylation still inhibits viral replication by reducing viral gene expression and virion release. We also identified a viral ISG15 substrate that also acts as an inhibitor of ISGylation. The data demonstrate that ISGylation is a critical innate immune response against HCMV infection and that evasion of ISG15-mediated immunity is necessary for productive viral infection.

▶Inquiry: Prof. Il-Doo Hwang (279-2291)

* This seminar will be given in English.
Please refrain from taking photos during seminars. *