The tumour suppressor APC promotes HIV-1 assembly via interaction with Gag precursor protein

Kei Miyakawa,Mayuko Nishi,Akiko Okayama,Satoko Matsunaga,Yuko Morikawa,Naoki Yamamoto,Akira Ono,Ayumi Kudoh,Hirokazu Kimura,Akihide Ryo,Masaki Anraku,Hisashi Hirano

doi:10.1038/ncomms14259

Abstract

Diverse cellular proteins and RNAs are tightly regulated in their subcellular localization to exert their local function. Here we report that the tumour suppressor adenomatous polyposis coli protein (APC) directs the localization and assembly of human immunodeficiency virus (HIV)-1 Gag polyprotein at distinct membrane components to enable the efficient production and spread of infectious viral particles. A proteomic analysis and subsequent biomolecular interaction assay reveals that the carboxyl terminus of APC interacts with the matrix region of Gag. Ectopic expression of APC, but not its familial adenomatous polyposis-related truncation mutant, prominently enhances HIV-1 production. Conversely, the depletion of APC leads to a significant decrease in membrane targeting of viral components, resulting in the severe loss of production of infectious virions. Furthermore, APC promotes the directional assembly of viral components at virological synapses, thereby facilitating cell-to-cell viral transmission. These findings reveal an unexpected role of APC in the directional spread of HIV-1.

Highlights

Diverse cellular proteins and RNAs are tightly regulated in their subcellular localization to exert their local function
We purified the Gag-associated complex from the cell lysates of HEK293 cells expressing human immunodeficiency virus (HIV)-1 Gag fused to a C-terminal tandem affinity purification (TAP) tag, which contains an IgG-binding motif and calmodulinbinding motif separated by a tobacco etch virus (TEV) protease cleavage site (Fig. 1a)
This interaction was found in HIV-1-infected T cells, where Gag protein was immunoprecipated with endogenous adenomatous polyposis coli protein (APC) (Fig. 1e)

Summary

Introduction

Diverse cellular proteins and RNAs are tightly regulated in their subcellular localization to exert their local function. We report that the tumour suppressor adenomatous polyposis coli protein (APC) directs the localization and assembly of human immunodeficiency virus (HIV)-1 Gag polyprotein at distinct membrane components to enable the efficient production and spread of infectious viral particles. In polarized cells, viral components are dynamically transported to defined domains and/or structures on the PM, including membrane nanotubes, filopodial bridges or uropods, for efficient assembly and budding. In polarized cells, viral components are dynamically transported to defined domains and/or structures on the PM, including membrane nanotubes, filopodial bridges or uropods, for efficient assembly and budding15,16 These specific membrane structures are generally enriched with actin filaments and can provide the topological spaces for the formation of infectious viral particles, and their deliberate spread with spatial orientation. These findings uncover a previously uncharacterized function of APC in HIV-1 replication and provide important new insights into the molecular mechanisms underlying HIV-1–host cell interactions

Methods

Results

Conclusion