Mono-ubiquitylated ORF45 Mediates Association of KSHV Particles with Internal Lipid Rafts for Viral Assembly and Egress.

Herpesviruses acquire their envelope by budding into the lumen of cytoplasmic membrane vesicles. This process is initiated by component(s) on viral particles, which recognize the budding site where the viral glycoproteins are present and recruit cellular cargo transport and sorting machinery to the...

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Main Authors: Xin Wang, Nannan Zhu, Wenwei Li, Fanxiu Zhu, Yan Wang, Yan Yuan
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2015-12-01
Series:PLoS Pathogens
Online Access:http://europepmc.org/articles/PMC4674120?pdf=render
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author Xin Wang
Nannan Zhu
Wenwei Li
Fanxiu Zhu
Yan Wang
Yan Yuan
author_facet Xin Wang
Nannan Zhu
Wenwei Li
Fanxiu Zhu
Yan Wang
Yan Yuan
author_sort Xin Wang
collection DOAJ
description Herpesviruses acquire their envelope by budding into the lumen of cytoplasmic membrane vesicles. This process is initiated by component(s) on viral particles, which recognize the budding site where the viral glycoproteins are present and recruit cellular cargo transport and sorting machinery to the site to complete the budding process. Proteins in the tegument layer, connecting capsid and envelope, are candidates for the recognition of budding sites on vesicle membrane and induction of budding and final envelopment. We examined several outer and matrix tegument proteins of Kaposi's sarcoma-associated herpesvirus (KSHV) and found that ORF45 associates with lipid rafts (LRs) of cellular membrane. LRs are membrane micro-domains, which have been implicated as relay stations in intracellular signaling and transport including viral entry and virion assembly. The ability of ORF45 to target LR is dependent on the mono-ubiquitylation of ORF45 at Lys297 as the mutation at Lys297 (K297R) abolished LR-association of ORF45. The K297R mutation also impairs ORF45 and viral particle co-localization with trans-Golgi network and endosomes, but facilitates ORF45 and viral particles co-localizing with lysosomes. More importantly, the recombinant KSHV carrying ORF45 K297R mutant (BAC-K297R) was found severely defective in producing mature and infectious virion particles in comparison to wild type KSHV (BAC16). Taken together, our results reveal a new function of KSHV tegument protein ORF45 in targeting LR of host cell membrane, promoting viral particles co-localization with trans-Golgi and endosome vesicles and facilitating the maturation and release of virion particles, suggesting that ORF45 plays a role in bringing KSHV particles to the budding site on cytoplasmic vesicle membrane and triggering the viral budding process for final envelopment and virion maturation.
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spelling doaj.art-b432be1d7a504430b1f43eb75311ff8c2022-12-22T01:06:37ZengPublic Library of Science (PLoS)PLoS Pathogens1553-73661553-73742015-12-011112e100533210.1371/journal.ppat.1005332Mono-ubiquitylated ORF45 Mediates Association of KSHV Particles with Internal Lipid Rafts for Viral Assembly and Egress.Xin WangNannan ZhuWenwei LiFanxiu ZhuYan WangYan YuanHerpesviruses acquire their envelope by budding into the lumen of cytoplasmic membrane vesicles. This process is initiated by component(s) on viral particles, which recognize the budding site where the viral glycoproteins are present and recruit cellular cargo transport and sorting machinery to the site to complete the budding process. Proteins in the tegument layer, connecting capsid and envelope, are candidates for the recognition of budding sites on vesicle membrane and induction of budding and final envelopment. We examined several outer and matrix tegument proteins of Kaposi's sarcoma-associated herpesvirus (KSHV) and found that ORF45 associates with lipid rafts (LRs) of cellular membrane. LRs are membrane micro-domains, which have been implicated as relay stations in intracellular signaling and transport including viral entry and virion assembly. The ability of ORF45 to target LR is dependent on the mono-ubiquitylation of ORF45 at Lys297 as the mutation at Lys297 (K297R) abolished LR-association of ORF45. The K297R mutation also impairs ORF45 and viral particle co-localization with trans-Golgi network and endosomes, but facilitates ORF45 and viral particles co-localizing with lysosomes. More importantly, the recombinant KSHV carrying ORF45 K297R mutant (BAC-K297R) was found severely defective in producing mature and infectious virion particles in comparison to wild type KSHV (BAC16). Taken together, our results reveal a new function of KSHV tegument protein ORF45 in targeting LR of host cell membrane, promoting viral particles co-localization with trans-Golgi and endosome vesicles and facilitating the maturation and release of virion particles, suggesting that ORF45 plays a role in bringing KSHV particles to the budding site on cytoplasmic vesicle membrane and triggering the viral budding process for final envelopment and virion maturation.http://europepmc.org/articles/PMC4674120?pdf=render
spellingShingle Xin Wang
Nannan Zhu
Wenwei Li
Fanxiu Zhu
Yan Wang
Yan Yuan
Mono-ubiquitylated ORF45 Mediates Association of KSHV Particles with Internal Lipid Rafts for Viral Assembly and Egress.
PLoS Pathogens
title Mono-ubiquitylated ORF45 Mediates Association of KSHV Particles with Internal Lipid Rafts for Viral Assembly and Egress.
title_full Mono-ubiquitylated ORF45 Mediates Association of KSHV Particles with Internal Lipid Rafts for Viral Assembly and Egress.
title_fullStr Mono-ubiquitylated ORF45 Mediates Association of KSHV Particles with Internal Lipid Rafts for Viral Assembly and Egress.
title_full_unstemmed Mono-ubiquitylated ORF45 Mediates Association of KSHV Particles with Internal Lipid Rafts for Viral Assembly and Egress.
title_short Mono-ubiquitylated ORF45 Mediates Association of KSHV Particles with Internal Lipid Rafts for Viral Assembly and Egress.
title_sort mono ubiquitylated orf45 mediates association of kshv particles with internal lipid rafts for viral assembly and egress
url http://europepmc.org/articles/PMC4674120?pdf=render
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