Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học Journal of Biology đề tài: Bending out and breaking away: host-cell accomplices in retroviral escape. | J. Biol. Journal of Biology BioMed Central Minireview Bending out and breaking away host-cell accomplices in retroviral escape Melvyn W Yap and Jonathan P Stoye Address Division of Virology National Institute for Medical Research The Ridgeway London NW7 1AA UK. Correspondence Jonathan Stoye. E-mail jstoye@ Published 19 December 2003 Journal of Biology 2003 3 3 The electronic version of this article is the complete one and can be found online at http content 3 1 3 2003 BioMed Central Ltd Abstract Budding through the host-cell membrane is a key step in the life cycle of many viruses. Recent studies of retrovirus replication implicate a large number of cellular proteins in this process. How do enveloped viruses bud from their host cells To understand how this process is achieved several fundamental steps must be considered. First viral structural components must be transported to the appropriate site typically just under a cell membrane and there assembled Figure 1a 1 . Second the plasma membrane must be distorted to make a succession of curved budding structures Figure 1b c this requires overcoming the mechanical bending resistance of the plasma membrane 2 . Third following the formation of the bud the virus has to pinch off and escape from the cell Figure 1d e 3 . This involves machinery that constricts the neck of the bud resulting in fusion between the membranes on either side of the neck and the release of the virus from the plasma membrane. Studies with a number of virus types most prominently retroviruses have now revealed that cellular proteins that are intimately involved in intracellular membrane trafficking and receptor re-localization play key roles in facilitating these processes. For a long time it has been known that the only retroviral component required for assembly and budding is the Gag polyprotein which ultimately forms the viral core 1 . Gag is cleaved into a variety of smaller components as the virus matures. These include
