tailieunhanh - Báo cáo y học: "Orthoretroviral-like prototype foamy virus gag-pol expression is compatible with viral replication"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Respiratory Research cung cấp cho các bạn kiến thức về ngành y đề tài: Orthoretroviral-like prototype foamy virus gag-pol expression is compatible with viral replication. | Swiersy et al. Retrovirology 2011 8 66 http content 8 1 66 RETR0VIR0L0GY RESEARCH Open Access Orthoretroviral-like prototype foamy virus gag-pol expression is compatible with viral replication 12 12 12 3 12 Anka Swiersy Constanze Wiek Juliane Reh Hanswalter Zentgraf and Dirk Lindemann Abstract Background Foamy viruses FVs unlike orthoretroviruses express Pol as a separate precursor protein and not as a Gag-Pol fusion protein. A unique packaging strategy involving recognition of briding viral RNA by both Pol precursor and Gag as well as potential Gag-Pol protein interactions ensures Pol particle encapsidation. Results Several Prototype FV PFV Gag-Pol fusion protein constructs were generated to examine whether PFV replication is compatible with an orthoretroviral-like Pol expression. During their analysis non-particle-associated secreted Pol precursor protein was discovered in extracellular wild type PFV particle preparations of different origin copurifying in simple virion enrichment protocols. Different analysis methods suggest that extracellular wild type PFV particles contain predominantly mature p85PR-RTand p40IN Pol subunits. Characterization of various PFV Gag-Pol fusion constructs revealed that PFV Pol expression in an orthoretroviral manner is compatible with PFV replication as long as a proteolytic processing between Gag and Pol proteins is possible. PFV Gag-Pol translation by a HIV-1 like ribosomal frameshift signal resulted in production of replication-competent virions although cell-and particle-associated Pol levels were reduced in comparison to wild type. In-frame fusion of PFV Gag and Pol ORFs led to increased cellular Pol levels but particle incorporation was only marginally elevated. Unlike that reported for similar orthoretroviral constructs a full-length in-frame PFV Gag-Pol fusion construct showed wildtype-like particle release and infectivity characteristics. In contrast in-frame PFV Gag-Pol fusion with C-terminal Gag ORF .