Virological characterization of HIV‐1 CA‐NTD mutants constructed in a virus‐lineage reflected manner

Nakanishi, Shoko; Watanabe, Suzuno; Doi, Naoya; Koma, Takaaki; Adachi, Akio; Nomaguchi, Masako

doi:10.2152/jmi.65.110

Cited by 4 publications

(11 citation statements)

References 29 publications

(32 reference statements)

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“…HIV-1 and HIV-2 CA proteins share 67% sequence identity. The amino acid variations indicate subtle differences in the chemical environment in their Gag hexamer and lattice structures [32,33]. At the Gag lattice three-fold interface, we found that exchanging HIV-1 and HIV-2 residues significantly reduced virus particle production, and diminished virus infectivity.…”

Section: Discussionmentioning

confidence: 99%

HIV-2 Immature Particle Morphology Provides Insights into Gag Lattice Stability and Virus Maturation

Talledge

Yang

Shi

et al. 2022

Preprint

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Retrovirus immature particle morphology consists of a membrane enclosed, pleomorphic, spherical and incomplete lattice of Gag hexamers. Previously, we demonstrated that human immunodeficiency virus type 2 (HIV-2) immature particles possess a distinct and extensive Gag lattice morphology. To better understand the nature of the continuously curved hexagonal Gag lattice, we used single particle cryo-electron microscopy to determine the HIV-2 Gag lattice structure for immature virions. The reconstruction map revealed a stable, wineglass-shaped Gag hexamer structure with structural features consistent with other lentiviral immature Gag structures. We also solved a 1.98 Å resolution crystal structure of the carboxyl-terminal domain (CTD) of the HIV-2 capsid (CA) protein that identified a structured helix 12 supported via an interaction of helix 10 in the absence of the SP1 region of Gag. Residues at the helix 10-12 interface proved critical in maintaining HIV-2 particle release and infectivity. Taken together, our findings provide evidence for a novel stabilization interface mediated by the HIV-2 CACTD that delivers important clues for HIV Gag lattice stabilization as well as important insights into virus maturation.

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Section: Discussionmentioning

confidence: 99%

HIV-2 Immature Particle Morphology Provides Insights into Gag Lattice Stability and Virus Maturation

Talledge

Yang

Shi

et al. 2022

Preprint

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“…Although its importance in the Gag assembly has not formally been described, H7 forms a hydrophobic patch along the CA-CA interface (Fig. 7A) and was recently shown by us to play a critical role in virus particle production (48). The significance of the H3 patch (Fig.…”

Section: Virus Particle Production In H9 Cells Bcmentioning

confidence: 96%

Allosteric Regulation of HIV-1 Capsid Structure for Gag Assembly, Virion Production, and Viral Infectivity by a Disordered Interdomain Linker

Koma

Kotani

Miyakawa

et al. 2019

J Virol

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The retroviral Gag capsid (Gag-CA) interdomain linker is an unstructured peptide segment connecting structured N-terminal and C-terminal domains. Although the region is reported to play roles in virion morphogenesis and infectivity, underlying molecular mechanisms remain unexplored. To address this issue, we determined biological and molecular phenotypes of HIV-1 CA linker mutants by experimental and in silico approaches. Among the nine linker mutants tested, eight exhibited attenuation of viral particle production to various extents mostly in parallel with a reduction in viral infectivity. Sucrose density gradient, confocal microscopy, and live-cell protein interaction analyses indicated that the defect is accompanied by attenuation of Gag-Gag interactions following Gag plasma membrane targeting in the cells. In silico analyses revealed distinct distributions of interaction-prone hydrophobic patches between immature and mature CA proteins. Molecular dynamics simulations predicted that the linker mutations can allosterically alter structural fluctuations, including the interaction surfaces apart from the mutation sites in both the immature and mature CA proteins. These results suggest that the HIV-1 CA interdomain linker is a cis-modulator of the CA interaction surfaces to optimize efficiency of Gag assembly, virion production, and viral infectivity. IMPORTANCE HIV-1 particle production and infection are highly ordered processes. Viral Gag proteins play a central role in the assembly and disassembly of viral molecules. Of these, capsid protein (CA) is a major contributor to the Gag-Gag interactions. CA consists of two structured domains, i.e., N-terminal (NTD) and C-terminal (CTD) domains, connected by an unstructured domain named the interdomain linker. While multiple regions in the NTD and CTD are reported to play roles in virion morphogenesis and infectivity, the roles of the linker region in Gag assembly and virus particle formation remain elusive. In this study, we showed by biological and molecular analyses that the linker region functions as an intramolecular modulator to tune Gag assembly, virion production, and viral infectivity. Our study thus illustrates a hitherto-unrecognized mechanism, an allosteric regulation of CA structure by the disordered protein element, for HIV-1 replication.

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“…In a previous study, E128 residue was mutated to the corresponding HIV-2 residue (HIV-1 E128N) and found to decrease viral replication [36]. HIV-2 N127E immature particle production is 4.3-fold less than WT ( Fig.…”

Section: Resultsmentioning

confidence: 97%

“…To assess if the equivalent mutations in HIV-1 (see Fig. 1A ) have similar impacts on particle infectivity, the site-direct mutant HIV-1 CA M39G mutant exhibited single-cycle infectivity rates xxx fold reduced from WT and HIV-1 CA N128E from a previous HIV-1 study reported 50-fold less than WT [36].…”

Section: Resultsmentioning

confidence: 99%

“…A previous study investigating HIV-1 and SIVmac residues swaps examined the mutant effects on particle infectivity and production [36]. Select mutations in HIV-1 CA Helix 7, such as E128N, I141C, were found less infectivity and reduced more than 50% particle production when swapped to the corresponding SIVmac residue [36]. This indicated that some non-conserved amino acids in HIV-1 CA Helix 7 showed important functions.…”

Section: Introductionmentioning

confidence: 99%

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Human immunodeficiency virus type 2 capsid protein mutagenesis reveals amino acid residues important for virus particle assembly

Yang

Talledge

Arndt

et al. 2022

Preprint

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Human immunodeficiency virus (HIV) Gag drives particle assembly. The capsid (CA) domain is critical for Gag oligomerization, and encodes key residues that dictate Gag-Gag interactions and particle morphology. The immature particle morphology of HIV-2 is intriguing different relative to that of HIV-1. To help define the critical determinants for Gag-Gag interactions and investigate the differences between HIV-1 and HIV-2, we have conducted mutagenesis in targeted locations of HIV-2 CA that have been implicated in Gag-Gag interactions. In particular, a panel of 31 site-directed mutants at the HIV-2 CA inter-hexamer interface, intra-hexamer interface and CA inter-domain linker have been created and analyzed for the efficiency of particle production, particle morphology, particle infectivity, Gag subcellular distribution and in vitro protein assembly. Seven conserved residues (L19A, A41, I152, K153, K157, N194, D196) and two non-conserved residues (G38, N127) were found that impact Gag multimerization and particle assembly. Taken together, these observations complement structural analyses of immature HIV-2 particle morphology and Gag lattice organization, and provide insights into the morphological differences between HIV-1 and HIV-2 immature particles and their impact on virus replication.

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Virological characterization of HIV‐1 CA‐NTD mutants constructed in a virus‐lineage reflected manner

Cited by 4 publications

References 29 publications

HIV-2 Immature Particle Morphology Provides Insights into Gag Lattice Stability and Virus Maturation

HIV-2 Immature Particle Morphology Provides Insights into Gag Lattice Stability and Virus Maturation

Allosteric Regulation of HIV-1 Capsid Structure for Gag Assembly, Virion Production, and Viral Infectivity by a Disordered Interdomain Linker

Human immunodeficiency virus type 2 capsid protein mutagenesis reveals amino acid residues important for virus particle assembly

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