# A multiscale approach for elucidating nuclear entry mechanisms of HIV-1 capsid

> **NIH NIH R01** · YALE UNIVERSITY · 2021 · $669,995

## Abstract

Project Summary
Human immunodeficiency virus type 1 (HIV-1) remains a major threat to global health. Therefore, it is essential
that we fully understand the mechanism of viral infectivity to provide new avenues for therapeutic development.
After invading a non-dividing host cell, HIV-1 must gain access to the genetic vault, the nucleus. To do this, the
viral genes, packaged in a capsid assembly, need to pass through nuclear pore complexes (NPCs). NPCs are
massive protein channels that function as the gatekeepers of the cell nucleus. However, how the HIV-1 capsid
breaches the barrier formed by the NPC remains poorly understood. Previous studies were hampered by the
complexity of the NPC structure and the lack of molecular-level details of capsid-nucleoporin interactions; there
was also a general inability of conventional in vitro platforms to capture the structural complexity of the viral
capsid, which presents patterns that are recognized by host factors. Therefore, unlocking more mechanistic
details of HIV-1 nuclear entry calls for innovative in vitro approaches capable of recapitulating higher-order
capsid assemblies and the native environment of nuclear pores. We propose to establish such a platform by
leveraging our recently established DNA-origami-based NPC mimics, termed NuPODs (NucleoPorins
Organized by DNA), which contain precisely controlled pore dimensions and nucleoporins grafted with
programmable density and orientation, as well as the programmable capsid protein (CA) assemblies that
faithfully recreate selective fragments or the entire HIV-1 capsid surface. We will further validate our in vitro
findings by infectivity experiments and live-cell imaging. Our multi-investigator team will draw from our
respective expertise, including HIV biochemistry, structural biology, DNA nanotechnology, nuclear transport,
and live-cell imaging, to build and apply this enabling platform for the study of HIV-1 capsid nuclear transport.
Specifically, we will first comprehensively study the interactions between HIV-1 capsids and an assortment of
cellular factors involved in HIV-1 nuclear import (Aim 1). Using soluble high-order CA assemblies and
recombinant nucleoporins, we will define the biochemical and structural basis of capsid-nucleoporin binding,
laying the foundation for the rest of the study. We will then build a library of NuPODs with increasing structural
and compositional complexity, to identify the key determinants of HIV-1 nuclear import and the associated
remodeling of the viral capsid and the NPC (Aim 2). These NuPODs will be built with multiple types of
nucleoporins positioned at designated positions on a DNA-origami channel with tunable dimensions and
stiffness. Systematically varying the NuPOD design and analyzing the resultant NuPOD-capsid docking and
insertion will help understand HIV-1 nuclear import with molecular-level details. Additionally, we will validate
our key findings using cell-based virologic experiments (Aim 3). Overall, ...

## Key facts

- **NIH application ID:** 10402986
- **Project number:** 1R01AI162260-01A1
- **Recipient organization:** YALE UNIVERSITY
- **Principal Investigator:** Chenxiang Lin
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $669,995
- **Award type:** 1
- **Project period:** 2021-09-17 → 2026-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10402986

## Citation

> US National Institutes of Health, RePORTER application 10402986, A multiscale approach for elucidating nuclear entry mechanisms of HIV-1 capsid (1R01AI162260-01A1). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10402986. Licensed CC0.

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