A Biophysical Investigation of HIV-1 Envelope Cytoplasmic-Tail Mediated Retention in the Gag Lattice
Date of Award
Schuyler B. van Engelenburg
J. Todd Blankenship
The infectivity of Human Immunodeficiency Virus is critically dependent on successful incorporation of the trimeric viral envelope glycoprotein, Envelope (Env), into Gag lattice assembly sites on the host-cell plasma membrane during virus biogenesis. The mechanistic nature of interaction between Gag, the structural protein, and Env, the viral spike, are dependent on the Gag matrix (MA) and Env cytoplasmic tail (CT) domains. Env laterally diffuses on the host cell plasma membrane until encountering a budding Gag lattice, where it is retained until particle scission and release. The mechanism of Env entry and retention in the lattice remains elusive and enigmatic. Here I aim to address the biophysical mechanisms that regulate the coalescence of these proteins through single-molecule and biochemical approaches. I provide a framework for quantifying the retention of Env at budding HIV-1 assembly sites using simultaneous single-particle tracking with respect to superresolution reconstructions of the viral bud on living cells in real time. Using this approach and a novel competitive inhibition assay, I also provide evidence that a monomeric Env CT is sufficient for virus particle incorporation and retention. Validation of monomeric retention and limited lattice accommodation provides evidence for a druggable interface that may be important for future antiretrovirals targeting the assembly of HIV. Lastly, I aim to provide a foundation for understanding the mechanistic interaction between Env-CT monomers and the Gag lattice by evaluating the retention and competitive properties of individual Env-CT domains in cellulo—a process difficult to achieve through mutations of the native Env trimer.
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Groves, Nicholas Scott, "A Biophysical Investigation of HIV-1 Envelope Cytoplasmic-Tail Mediated Retention in the Gag Lattice" (2021). Electronic Theses and Dissertations. 1936.
Received from ProQuest
Nicholas Scott Groves
Available for download on Monday, July 31, 2023