While it is clear that HIV-1 assembly occurs predominantly on the plasma membrane (PM), the itinerary that the Gag precursor follows to reach its destination remains ill defined. Likewise, the host cell machinery that promotes Gag trafficking to the PM is incompletely understood. We and others have demonstrated that the matrix (MA) domain of Gag regulates targeting to the site of virus assembly, and we discovered that the phosphoinositide PI(4,5)P2 and the ADP ribosylation factors (Arfs) serve important functions in directing Pr55Gag to the PM. We are actively engaged in studies to elucidate further the cellular machinery involved in HIV-1 Gag trafficking. This effort combines virology, biochemistry, cell biology, and imaging techniques and is also being extended to the nonprimate lentiviruses equine infectious anemia virus (EIAV) and feline immunodeficiency virus (FIV). Proteins of particular interest in this area include the Arf proteins, SNAREs, F-BAR domain proteins, clathrin, and FLJ90680. In studies related to Gag trafficking, we are also investigating the host cell machinery required for Gag localization to, and virus transfer across, the virological synapse. The viral envelope (Env) glycoproteins are incorporated into virions during the assembly process. We have shown that point mutations in the MA domain of Gag block Env incorporation, and demonstrated that the long gp41 cytoplasmic tail plays a cell-type-dependent role in Env incorporation. Despite the evidence for a direct interaction between MA and the gp41 cytoplasmic tail, the molecular mechanism by which Env is incorporated and the basis for cell type dependence of cytoplasmic tail function remain to be defined. We will address the hypothesis that host cell factors are likely to play an important role in Env incorporation into virions. We have developed a bimolecular fluorescence complementation (BiFC) assay for Gag-Env interaction that will be useful in evaluating this hypothesis. [Corresponds to Freed Project 1 in the October 2011 site visit report of the HIV Drug Resistance Program]

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Investigator-Initiated Intramural Research Projects (ZIA)
Project #
1ZIABC010775-07
Application #
8763209
Study Section
Project Start
Project End
Budget Start
Budget End
Support Year
7
Fiscal Year
2013
Total Cost
$709,199
Indirect Cost
Name
National Cancer Institute Division of Basic Sciences
Department
Type
DUNS #
City
State
Country
Zip Code
Chen, Antony K; Sengupta, Prabuddha; Waki, Kayoko et al. (2014) MicroRNA binding to the HIV-1 Gag protein inhibits Gag assembly and virus production. Proc Natl Acad Sci U S A 111:E2676-83
Daniels, Sarah I; Soule, Erin E; Davidoff, Katharine S et al. (2014) Activation of virus uptake through induction of macropinocytosis with a novel polymerizing peptide. FASEB J 28:106-16
Van Engelenburg, Schuyler B; Shtengel, Gleb; Sengupta, Prabuddha et al. (2014) Distribution of ESCRT machinery at HIV assembly sites reveals virus scaffolding of ESCRT subunits. Science 343:653-6
Freed, Eric O; Gale Jr, Michael (2014) Antiviral innate immunity: editorial overview. J Mol Biol 426:1129-32
Luttge, Benjamin G; Panchal, Prashant; Puri, Vinita et al. (2014) Mutations in the feline immunodeficiency virus envelope glycoprotein confer resistance to a dominant-negative fragment of Tsg101 by enhancing infectivity and cell-to-cell virus transmission. Biochim Biophys Acta 1838:1143-52
Joshi, Anjali; Ablan, Sherimay D; Soheilian, Ferri et al. (2009) Evidence that productive human immunodeficiency virus type 1 assembly can occur in an intracellular compartment. J Virol 83:5375-87
Adamson, Catherine S; Freed, Eric O (2009) Anti-HIV-1 therapeutics: from FDA-approved drugs to hypothetical future targets. Mol Interv 9:70-4
Waheed, Abdul A; Ono, Akira; Freed, Eric O (2009) Methods for the study of HIV-1 assembly. Methods Mol Biol 485:163-84
Adamson, Catherine S; Freed, Eric O (2008) Recent progress in antiretrovirals--lessons from resistance. Drug Discov Today 13:424-32
Joshi, Anjali; Garg, Himanshu; Nagashima, Kunio et al. (2008) GGA and Arf proteins modulate retrovirus assembly and release. Mol Cell 30:227-38

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