A Biophysical Investigation of HIV-1 Envelope Cytoplasmic-Tail Mediated Retention in the Gag Lattice

<p>The infectivity of <em>Human Immunodeficiency Virus</em> 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<em> in cellulo</em>—a process difficult to achieve through mutations of the native Env trimer.</p>

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Year dc:date.available

2021

Author dc:creator

• Groves, Nicholas Scott

Contributors dc:contributor

• Schuyler B. van Engelenburg
• Michelle Knowles
• Cedric Asensio
• J. Todd Blankenship

• Biophysics
• HIV
• Biochemistry, Biophysics, and Structural Biology
• Immunology and Infectious Disease
• Life Sciences

Statement dc:rights

• <p>Copyright is held by the author. User is responsible for all copyright compliance.</p>

Language dc:language

en

Repository record dc:identifier

https://digitalcommons.du.edu/etd/1936

OAI identifier oai:identifier

oai:digitalcommons.du.edu:etd-2927