Publications by authors named "Andrew J Piefer"

The endosomal sorting complex I required for transport (ESCRT-I) is composed of the three subunits Vps23/Tsg101, Vps28 and Vps37. ESCRT-I is recruited to cellular membranes during multivesicular endosome biogenesis and by enveloped viruses such as HIV-1 to mediate budding from the cell. Here, we describe the crystal structure of a conserved C-terminal domain from Sacharomyces cerevisiae Vps28 (Vps28-CTD) at 3.

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Current targets for antiretroviral therapy (ART) include the viral enzymes reverse transcriptase and protease. The use of a combination of inhibitors targeting these enzymes can reduce viral load for a prolonged period and delay disease progression. However, complications of ART, including the emergence of viruses resistant to current drugs, are driving the development of new antiretroviral agents targeting not only the reverse transcriptase and protease enzymes but novel targets as well.

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Severe acute respiratory syndrome-associated coronavirus (SARS-CoV) is a rapidly emerging pathogen with potentially serious consequences for public health. Here we describe conditions that result not only in the efficient expression of the SARS-CoV spike (S) protein on the surface of cells, but in its incorporation into lentiviral particles that can be used to transduce cells in an S glycoprotein-dependent manner. We found that although some primate cell lines, including Vero E6, 293T and Huh-7 cells, could be efficiently transduced by SARS-CoV S glycoprotein pseudoviruses, other cells lines were either resistant or very poorly permissive to virus entry.

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A final step in retrovirus assembly, particle release from the cell, is modulated by a small motif in the Gag protein known as a late domain. Recently, human immunodeficiency virus type 1 (HIV-1) and Moloney murine leukemia virus (M-MuLV) were shown to require components of the cellular vacuolar protein sorting (VPS) machinery for efficient viral release. HIV-1 interacts with the VPS pathway via an association of HIV-1 Gag with TSG101, a component of the cellular complexes involved in VPS.

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The human T-cell leukemia virus type-2 (HTLV-2) integrase (IN) catalyzes the insertion of the viral genome into the host chromosome. HTLV-2 IN was expressed as an N-terminal hexa-histidine tagged protein in the methylotrophic yeast Pichia pastoris and as a C-terminal hexa-histidine fusion in Escherichia coli. Maximal IN expression was observed at 48h post-induction for the yeast system and 2h post-induction for E.

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