Date of Award

2021

Document Type

Dissertation

Degree Name

Ph.D.

Department

Biological Sciences

First Advisor

Schuyler B. van Engelenburg

Second Advisor

Michelle Knowles

Third Advisor

Cedric Asensio

Fourth Advisor

J. Todd Blankenship

Keywords

Biophysics, HIV

Abstract

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.

Publication Statement

Copyright is held by the author. User is responsible for all copyright compliance.

Provenance

Received from ProQuest

Rights holder

Nicholas Scott Groves

File size

116 pgs

File format

application/pdf

Language

en

Discipline

Biophysics

Available for download on Thursday, December 22, 2022

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