http://www.mdpi.com/journal/viruses/special_issues/ubiquitin-vir-infect/ {snippet name="submission_info"} http://www.mdpi.com/1999-4915/3/2/118/ Cells communicate with each other and the outside world through surface receptors, which need to be tightly regulated to prevent both overstimulation and receptor desensitization. Understanding the processes involved in the homeostatic control of cell surface receptors is essential, but we are not alone in trying to regulate these receptors. Viruses, as the ultimate host pathogens, have co-evolved over millions of years and have both pirated and adapted host genes to enable viral pathogenesis. K3 and K5 (also known as MIR1 and MIR2) are viral ubiquitin E3 ligases from Kaposi’s Sarcoma Associated Herpesvirus (KSHV) which decrease expression of a number of cell surface receptors and have been used to interrogate cellular processes and improve our understanding of ubiquitin-mediated receptor endocytosis and degradation. In this review, we summarize what has been learned from the study of these viral genes and emphasize their role in elucidating the complexity of ubiquitin in receptor regulation. http://www.mdpi.com/1999-4915/3/2/118/ Fri, 28 Jan 2011 00:00:00 CET Viruses 2011-01-28 3 2 Review 118 131 1999-4915 What Has the Study of the K3 and K5 Viral Ubiquitin E3 Ligases Taught Us about Ubiquitin-Mediated Receptor Regulation? 2011-01-28 doi: 10.3390/v3020118 Jessica M. Boname Paul J. Lehner http://www.mdpi.com/1999-4915/2/10/2356/ Ubiquitination plays a critical role in many cellular processes. A growing number of viruses have evolved strategies to exploit the ubiquitin-proteasome system, including members of the Poxviridae family. Members of the poxvirus family have recently been shown to encode BTB/kelch and ankyrin/F-box proteins that interact with cullin-3 and cullin-1 based ubiquitin ligases, respectively. Multiple members of the poxvirus family also encode ubiquitin ligases with intrinsic activity. This review describes the numerous mechanisms that poxviruses employ to manipulate the ubiquitin-proteasome system. http://www.mdpi.com/1999-4915/2/10/2356/ Tue, 19 Oct 2010 00:00:00 CEST Viruses 2010-10-19 2 10 Review 2356 2380 1999-4915 Poxvirus Exploitation of the Ubiquitin-Proteasome System 2010-10-19 doi: 10.3390/v2102356 Michele Barry Nicholas Van Buuren Kristin Burles Kelly Mottet Qian Wang Alastair Teale http://www.mdpi.com/1999-4915/2/10/2154/ The type I interferon system plays a critical role in limiting the spread of viral infection. Viruses induce the production of interferon (IFN), which after binding to the IFN-α/β receptor (IFNAR), and triggering of the JAK/STAT signaling cascade, results in the induction of interferon-stimulated genes (ISGs). These ISGs function to inhibit viral replication and to regulate the host immune response. Among these ISGs, the ubiquitin-like molecule, ISG15, is one of the most strongly induced proteins. Similar to ubiquitin, through an IFN induced conjugation cascade, ISG15 is covalently linked to a variety of cellular proteins, suggesting regulation of different cellular processes. Studies performed over the past several years have shown that ISG15 plays a central role in the host’s antiviral response against many viruses. Mice lacking ISG15 display increased susceptibility to multiple viruses. Furthermore, several viruses have developed immune evasion strategies that directly target the ISG15 pathway. Work is now underway to determine the mechanism by which ISG15 functions as an antiviral molecule, such that therapies targeting this pathway can be developed in the future. http://www.mdpi.com/1999-4915/2/10/2154/ Tue, 28 Sep 2010 00:00:00 CEST Viruses 2010-09-28 2 10 Review 2154 2168 1999-4915 Antiviral Properties of ISG15 2010-09-28 doi: 10.3390/v2102154 Deborah J. Lenschow