tailieunhanh - Báo cáo y học: "Autoprocessing of human immunodeficiency virus type 1 protease miniprecursor fusions in mammalian cells"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Wertheim cung cấp cho các bạn kiến thức về ngành y đề tài: Autoprocessing of human immunodeficiency virus type 1 protease miniprecursor fusions in mammalian cells. | Huang and Chen AIDS Research and Therapy 2010 7 27 http content 7 1 27 AIDS RESEARCH AND THERAPY RESEARCH Open Access Autoprocessing of human immunodeficiency virus type 1 protease miniprecursor fusions in mammalian cells Liangqun Huang Chaoping Chen Abstract Background HIV protease PR is a virus-encoded aspartic protease that is essential for viral replication and infectivity. The fully active and mature dimeric protease is released from the Gag-Pol polyprotein as a result of precursor autoprocessing. Results We here describe a simple model system to directly examine HIV protease autoprocessing in transfected mammalian cells. A fusion precursor was engineered encoding GST fused to a well-characterized miniprecursor consisting of the mature protease along with its upstream transframe region TFR and small peptide epitopes to facilitate detection of the precursor substrate and autoprocessing products. In HEK 293T cells the resulting chimeric precursor undergoes effective autoprocessing producing mature protease that is rapidly degraded likely via autoproteolysis. The known protease inhibitors Darunavir and Indinavir suppressed both precursor autoprocessing and autoproteolysis in a dose-dependent manner. Protease mutations that inhibit Gag processing as characterized using proviruses also reduced autoprocessing efficiency when they were introduced to the fusion precursor. Interestingly autoprocessing of the fusion precursor requires neither the full proteolytic activity nor the majority of the N-terminal TFR region. Conclusions We suggest that the fusion precursors provide a useful system to study protease autoprocessing in mammalian cells and may be further developed for screening of new drugs targeting HIV protease autoprocessing. Background Human immunodeficiency virus 1 HIV-1 is the causative pathogen of AIDS. The HIV protease is a virus-encoded enzyme absolutely required for virus propagation and infectivity. In the HIV infected cell .