How HIV-1 Uses the Metabolite Inositol Hexakisphosphate to Build Its Capsid

The HIV-1 capsid is one of virology’s most iconic structures, yet how it assembles has long remained elusive. Remarkably, the capsid is made from just a single protein, CA, which forms a lattice of ~250 hexamers and exactly 12 pentamers. Conical capsids form inside budded virions during maturation,...

Full description

Saved in:
Bibliographic Details
Main Author: Leo C. James
Format: Article
Language:English
Published: MDPI AG 2025-05-01
Series:Viruses
Subjects:
Online Access:https://www.mdpi.com/1999-4915/17/5/689
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850125883905409024
author Leo C. James
author_facet Leo C. James
author_sort Leo C. James
collection DOAJ
description The HIV-1 capsid is one of virology’s most iconic structures, yet how it assembles has long remained elusive. Remarkably, the capsid is made from just a single protein, CA, which forms a lattice of ~250 hexamers and exactly 12 pentamers. Conical capsids form inside budded virions during maturation, but early efforts to reproduce this in vitro resulted instead in open-ended tubes with a purely hexameric lattice. The missing component in capsid assembly was finally identified as the metabolite inositol hexakisphosphate (IP6). Simply mixing soluble CA protein with IP6 is sufficient to drive the spontaneous assembly of conical capsids with a similar size and shape to those inside of infectious virions. Equally important, IP6 stabilises capsids once formed, increasing their stability from minutes to hours. Indeed, such is the dependence of HIV-1 on IP6 that the virus actively packages it into virions during production. These discoveries have stimulated work from multiple labs into the role and importance of IP6 in HIV-1 replication, and is the subject of this review.
format Article
id doaj-art-2c33f942d7cb42b390d01cef58461bb8
institution OA Journals
issn 1999-4915
language English
publishDate 2025-05-01
publisher MDPI AG
record_format Article
series Viruses
spelling doaj-art-2c33f942d7cb42b390d01cef58461bb82025-08-20T02:34:02ZengMDPI AGViruses1999-49152025-05-0117568910.3390/v17050689How HIV-1 Uses the Metabolite Inositol Hexakisphosphate to Build Its CapsidLeo C. James0MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UKThe HIV-1 capsid is one of virology’s most iconic structures, yet how it assembles has long remained elusive. Remarkably, the capsid is made from just a single protein, CA, which forms a lattice of ~250 hexamers and exactly 12 pentamers. Conical capsids form inside budded virions during maturation, but early efforts to reproduce this in vitro resulted instead in open-ended tubes with a purely hexameric lattice. The missing component in capsid assembly was finally identified as the metabolite inositol hexakisphosphate (IP6). Simply mixing soluble CA protein with IP6 is sufficient to drive the spontaneous assembly of conical capsids with a similar size and shape to those inside of infectious virions. Equally important, IP6 stabilises capsids once formed, increasing their stability from minutes to hours. Indeed, such is the dependence of HIV-1 on IP6 that the virus actively packages it into virions during production. These discoveries have stimulated work from multiple labs into the role and importance of IP6 in HIV-1 replication, and is the subject of this review.https://www.mdpi.com/1999-4915/17/5/689HIV-1IP6retrovirusescapsidstructurevirus replication
spellingShingle Leo C. James
How HIV-1 Uses the Metabolite Inositol Hexakisphosphate to Build Its Capsid
Viruses
HIV-1
IP6
retroviruses
capsid
structure
virus replication
title How HIV-1 Uses the Metabolite Inositol Hexakisphosphate to Build Its Capsid
title_full How HIV-1 Uses the Metabolite Inositol Hexakisphosphate to Build Its Capsid
title_fullStr How HIV-1 Uses the Metabolite Inositol Hexakisphosphate to Build Its Capsid
title_full_unstemmed How HIV-1 Uses the Metabolite Inositol Hexakisphosphate to Build Its Capsid
title_short How HIV-1 Uses the Metabolite Inositol Hexakisphosphate to Build Its Capsid
title_sort how hiv 1 uses the metabolite inositol hexakisphosphate to build its capsid
topic HIV-1
IP6
retroviruses
capsid
structure
virus replication
url https://www.mdpi.com/1999-4915/17/5/689
work_keys_str_mv AT leocjames howhiv1usesthemetaboliteinositolhexakisphosphatetobuilditscapsid