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Identification of a Structural Element in HIV-1 Gag Required for Virus Particle Assembly and Maturation

Late in the HIV-1 replication cycle, the viral structural protein Gag is targeted to virus assembly sites at the plasma membrane of infected cells. The capsid (CA) domain of Gag plays a critical role in the formation of the hexameric Gag lattice in the immature virion, and, during particle release,...

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Autores principales: Novikova, Mariia, Adams, Lucas J., Fontana, Juan, Gres, Anna T., Balasubramaniam, Muthukumar, Winkler, Dennis C., Kudchodkar, Sagar B., Soheilian, Ferri, Sarafianos, Stefan G., Steven, Alasdair C., Freed, Eric O.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Society for Microbiology 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6191540/
https://www.ncbi.nlm.nih.gov/pubmed/30327442
http://dx.doi.org/10.1128/mBio.01567-18
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author Novikova, Mariia
Adams, Lucas J.
Fontana, Juan
Gres, Anna T.
Balasubramaniam, Muthukumar
Winkler, Dennis C.
Kudchodkar, Sagar B.
Soheilian, Ferri
Sarafianos, Stefan G.
Steven, Alasdair C.
Freed, Eric O.
author_facet Novikova, Mariia
Adams, Lucas J.
Fontana, Juan
Gres, Anna T.
Balasubramaniam, Muthukumar
Winkler, Dennis C.
Kudchodkar, Sagar B.
Soheilian, Ferri
Sarafianos, Stefan G.
Steven, Alasdair C.
Freed, Eric O.
author_sort Novikova, Mariia
collection PubMed
description Late in the HIV-1 replication cycle, the viral structural protein Gag is targeted to virus assembly sites at the plasma membrane of infected cells. The capsid (CA) domain of Gag plays a critical role in the formation of the hexameric Gag lattice in the immature virion, and, during particle release, CA is cleaved from the Gag precursor by the viral protease and forms the conical core of the mature virion. A highly conserved Pro-Pro-Ile-Pro (PPIP) motif (CA residues 122 to 125) [PPIP(122–125)] in a loop connecting CA helices 6 and 7 resides at a 3-fold axis formed by neighboring hexamers in the immature Gag lattice. In this study, we characterized the role of this PPIP(122–125) loop in HIV-1 assembly and maturation. While mutations P123A and P125A were relatively well tolerated, mutation of P122 and I124 significantly impaired virus release, caused Gag processing defects, and abolished infectivity. X-ray crystallography indicated that the P122A and I124A mutations induce subtle changes in the structure of the mature CA lattice which were permissive for in vitro assembly of CA tubes. Transmission electron microscopy and cryo-electron tomography demonstrated that the P122A and I124A mutations induce severe structural defects in the immature Gag lattice and abrogate conical core formation. Propagation of the P122A and I124A mutants in T-cell lines led to the selection of compensatory mutations within CA. Our findings demonstrate that the CA PPIP(122–125) loop comprises a structural element critical for the formation of the immature Gag lattice.
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spelling pubmed-61915402018-10-26 Identification of a Structural Element in HIV-1 Gag Required for Virus Particle Assembly and Maturation Novikova, Mariia Adams, Lucas J. Fontana, Juan Gres, Anna T. Balasubramaniam, Muthukumar Winkler, Dennis C. Kudchodkar, Sagar B. Soheilian, Ferri Sarafianos, Stefan G. Steven, Alasdair C. Freed, Eric O. mBio Research Article Late in the HIV-1 replication cycle, the viral structural protein Gag is targeted to virus assembly sites at the plasma membrane of infected cells. The capsid (CA) domain of Gag plays a critical role in the formation of the hexameric Gag lattice in the immature virion, and, during particle release, CA is cleaved from the Gag precursor by the viral protease and forms the conical core of the mature virion. A highly conserved Pro-Pro-Ile-Pro (PPIP) motif (CA residues 122 to 125) [PPIP(122–125)] in a loop connecting CA helices 6 and 7 resides at a 3-fold axis formed by neighboring hexamers in the immature Gag lattice. In this study, we characterized the role of this PPIP(122–125) loop in HIV-1 assembly and maturation. While mutations P123A and P125A were relatively well tolerated, mutation of P122 and I124 significantly impaired virus release, caused Gag processing defects, and abolished infectivity. X-ray crystallography indicated that the P122A and I124A mutations induce subtle changes in the structure of the mature CA lattice which were permissive for in vitro assembly of CA tubes. Transmission electron microscopy and cryo-electron tomography demonstrated that the P122A and I124A mutations induce severe structural defects in the immature Gag lattice and abrogate conical core formation. Propagation of the P122A and I124A mutants in T-cell lines led to the selection of compensatory mutations within CA. Our findings demonstrate that the CA PPIP(122–125) loop comprises a structural element critical for the formation of the immature Gag lattice. American Society for Microbiology 2018-10-16 /pmc/articles/PMC6191540/ /pubmed/30327442 http://dx.doi.org/10.1128/mBio.01567-18 Text en https://doi.org/10.1128/AuthorWarrantyLicense.v1 This is a work of the U.S. Government and is not subject to copyright protection in the United States. Foreign copyrights may apply.
spellingShingle Research Article
Novikova, Mariia
Adams, Lucas J.
Fontana, Juan
Gres, Anna T.
Balasubramaniam, Muthukumar
Winkler, Dennis C.
Kudchodkar, Sagar B.
Soheilian, Ferri
Sarafianos, Stefan G.
Steven, Alasdair C.
Freed, Eric O.
Identification of a Structural Element in HIV-1 Gag Required for Virus Particle Assembly and Maturation
title Identification of a Structural Element in HIV-1 Gag Required for Virus Particle Assembly and Maturation
title_full Identification of a Structural Element in HIV-1 Gag Required for Virus Particle Assembly and Maturation
title_fullStr Identification of a Structural Element in HIV-1 Gag Required for Virus Particle Assembly and Maturation
title_full_unstemmed Identification of a Structural Element in HIV-1 Gag Required for Virus Particle Assembly and Maturation
title_short Identification of a Structural Element in HIV-1 Gag Required for Virus Particle Assembly and Maturation
title_sort identification of a structural element in hiv-1 gag required for virus particle assembly and maturation
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6191540/
https://www.ncbi.nlm.nih.gov/pubmed/30327442
http://dx.doi.org/10.1128/mBio.01567-18
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