Molecular Mechanisms of Virus BuddingEnveloped viruses acquire their lipid bilayers by budding through cellular membranes, but their mechanisms of release are unknown. The goal of our research is to determine how the structural components of these viruses move through the budding pathway, culminating in this virus-cell separation step. Our primary focus has been on the retroviral Gag protein because it is the only protein needed for the budding of these viruses; however, we have recently expanded efforts to address the more complicated herpesviruses, for which the minimal budding machinery is completely unknown.
Herpesvirus budding. Very little is known about the budding of herpesviruses. In recent years, it has become clear that these viruses (ulike retroviruses) bud into the trans Golgi network (see second figure). A great deal of genetic data suggest that there are probably several herpesvirus proteins that are needed for budding, and all of these reside in the "tegument" region of the virus (that part of the virus that is situated between the membrane and the capsid). The goal of our current experiments is to characterize the trafficking properties of tegument proteins that enable them to accumulate at the TGN compartment of the cell. We hope to eventually elucidate the minimal budding machinery of these viruses and to learn how that machinery interacts with the host cell to enable virus production. It will be interesting to see whether herpesviruses utilize some of the same host proteins that retroviruses use for budding. | 
