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Nakajima KI, Inagaki T, Espera JM, Izumiya Y. Kaposi's sarcoma-associated herpesvirus (KSHV) LANA prevents KSHV episomes from degradation. J Virol 2024; 98:e0126823. [PMID: 38240588 PMCID: PMC10878079 DOI: 10.1128/jvi.01268-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Accepted: 12/14/2023] [Indexed: 02/21/2024] Open
Abstract
Protein knockdown with an inducible degradation system is a powerful tool for studying proteins of interest in living cells. Here, we adopted the auxin-inducible degron (AID) approach to detail Kaposi's sarcoma-associated herpesvirus (KSHV) latency-associated nuclear antigen (LANA) function in latency maintenance and inducible viral lytic gene expression. We fused the mini-auxin-inducible degron (mAID) tag at the LANA N-terminus with KSHV bacterial artificial chromosome 16 recombination, and iSLK cells were stably infected with the recombinant KSHV encoding mAID-LANA. Incubation with 5-phenyl-indole-3-acetic acid, a derivative of natural auxin, rapidly degraded LANA within 1.5 h. In contrast to our hypothesis, depletion of LANA alone did not trigger lytic reactivation but rather decreased inducible lytic gene expression when we stimulated reactivation with a combination of ORF50 protein expression and sodium butyrate. Decreased overall lytic gene induction seemed to be associated with a rapid loss of KSHV genomes in the absence of LANA. The rapid loss of viral genomic DNA was blocked by a lysosomal inhibitor, chloroquine. Furthermore, siRNA-mediated knockdown of cellular innate immune proteins, cyclic AMP-GMP synthase (cGAS) and simulator of interferon genes (STING), and other autophagy-related genes rescued the degradation of viral genomic DNA upon LANA depletion. Reduction of the viral genome was not observed in 293FT cells that lack the expression of cGAS. These results suggest that LANA actively prevents viral genomic DNA from sensing by cGAS-STING signaling axis, adding novel insights into the role of LANA in latent genome maintenance.IMPORTANCESensing of pathogens' components is a fundamental cellular immune response. Pathogens have therefore evolved strategies to evade such cellular immune responses. KSHV LANA is a multifunctional protein and plays an essential role in maintaining the latent infection by tethering viral genomic DNA to the host chromosome. We adopted the inducible protein knockdown approach and found that depletion of LANA induced rapid degradation of viral genomic DNA, which is mediated by innate immune DNA sensors and autophagy pathway. These observations suggest that LANA may play a role in hiding KSHV episome from innate immune DNA sensors. Our study thus provides new insights into the role of LANA in latency maintenance.
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Affiliation(s)
- Ken-ichi Nakajima
- Department of Dermatology, School of Medicine, University of California Davis, Sacramento, California, USA
| | - Tomoki Inagaki
- Department of Dermatology, School of Medicine, University of California Davis, Sacramento, California, USA
| | - Jonna Magdallene Espera
- Department of Dermatology, School of Medicine, University of California Davis, Sacramento, California, USA
| | - Yoshihiro Izumiya
- Department of Dermatology, School of Medicine, University of California Davis, Sacramento, California, USA
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California Davis, Sacramento, California, USA
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Izumiya Y, Algalil A, Espera JM, Miura H, Izumiya C, Inagaki T, Kumar A. Kaposi's sarcoma-associated herpesvirus terminal repeat regulates inducible lytic gene promoters. J Virol 2024; 98:e0138623. [PMID: 38240593 PMCID: PMC10878276 DOI: 10.1128/jvi.01386-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 01/02/2024] [Indexed: 02/21/2024] Open
Abstract
The Kaposi's sarcoma-associated herpesvirus (KSHV) genome consists of an approximately 140-kb unique coding region flanked by 30-40 copies of a 0.8-kb terminal repeat (TR) sequence. A gene enhancer recruits transcription-related enzymes by having arrays of transcription factor binding sites. Here, we show that KSHV TR possesses transcription regulatory function with latency-associated nuclear antigen (LANA). Cleavage under targets and release using nuclease demonstrated that TR fragments were occupied by LANA-interacting histone-modifying enzymes in naturally infected cells. The TR was enriched with histone H3K27 acetylation (H3K27Ac) and H3K4 tri-methylation (H3K4me3) modifications and also expressed nascent RNAs. The sites of H3K27Ac and H3K4me3 modifications were also conserved in the KSHV unique region among naturally infected primary effusion lymphoma cells. KSHV origin of lytic replication (Ori-Lyt) showed similar protein and histone modification occupancies with that of TR. In the Ori-Lyt region, the LANA and LANA-interacting proteins colocalized with an H3K27Ac-modified nucleosome along with paused RNA polymerase II. The KSHV transactivator KSHV replication and transcription activator (K-Rta) recruitment sites franked the LANA-bound nucleosome, and reactivation evicted the LANA-bound nucleosome. Including TR fragments in reporter plasmid enhanced inducible viral gene promoter activities independent of the orientations. In the presence of TR in reporter plasmids, K-Rta transactivation was drastically increased, while LANA acquired the promoter repression function. KSHV TR, therefore, functions as an enhancer for KSHV inducible genes. However, in contrast to cellular enhancers bound by multiple transcription factors, perhaps the KSHV enhancer is predominantly regulated by the LANA nuclear body.IMPORTANCEEnhancers are a crucial regulator of differential gene expression programs. Enhancers are the cis-regulatory sequences determining target genes' spatiotemporal and quantitative expression. Here, we show that Kaposi's sarcoma-associated herpesvirus (KSHV) terminal repeats fulfill the enhancer definition for KSHV inducible gene promoters. The KSHV enhancer is occupied by latency-associated nuclear antigen (LANA) and its interacting proteins, such as CHD4. Neighboring terminal repeat (TR) fragments to lytic gene promoters drastically enhanced KSHV replication and transcription activator and LANA transcription regulatory functions. This study, thus, proposes a new latency-lytic switch model in which TR accessibility to the KSHV gene promoters regulates viral inducible gene expression.
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Affiliation(s)
- Yoshihiro Izumiya
- Department of Dermatology, School of Medicine, University of California Davis, Sacramento, California, USA
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California Davis, Sacramento, California, USA
| | - Adhraa Algalil
- Department of Dermatology, School of Medicine, University of California Davis, Sacramento, California, USA
- Midwestern University College of Dental Medicine, Glendale, Arizona, USA
| | - Jonna M. Espera
- Department of Dermatology, School of Medicine, University of California Davis, Sacramento, California, USA
| | - Hiroki Miura
- Department of Dermatology, School of Medicine, University of California Davis, Sacramento, California, USA
| | - Chie Izumiya
- Department of Dermatology, School of Medicine, University of California Davis, Sacramento, California, USA
| | - Tomoki Inagaki
- Department of Dermatology, School of Medicine, University of California Davis, Sacramento, California, USA
| | - Ashish Kumar
- Department of Dermatology, School of Medicine, University of California Davis, Sacramento, California, USA
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Martin EW, Iserman C, Olety B, Mitrea DM, Klein IA. Biomolecular Condensates as Novel Antiviral Targets. J Mol Biol 2024; 436:168380. [PMID: 38061626 DOI: 10.1016/j.jmb.2023.168380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 11/23/2023] [Accepted: 11/30/2023] [Indexed: 12/24/2023]
Abstract
Viral infections pose a significant health risk worldwide. There is a pressing need for more effective antiviral drugs to combat emerging novel viruses and the reemergence of previously controlled viruses. Biomolecular condensates are crucial for viral replication and are promising targets for novel antiviral therapies. Herein, we review the role of biomolecular condensates in the viral replication cycle and discuss novel strategies to leverage condensate biology for antiviral drug discovery. Biomolecular condensates may also provide an opportunity to develop antivirals that are broad-spectrum or less prone to acquired drug resistance.
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Zheng LW, Liu CC, Yu KD. Phase separations in oncogenesis, tumor progressions and metastasis: a glance from hallmarks of cancer. J Hematol Oncol 2023; 16:123. [PMID: 38110976 PMCID: PMC10726551 DOI: 10.1186/s13045-023-01522-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 12/12/2023] [Indexed: 12/20/2023] Open
Abstract
Liquid-liquid phase separation (LLPS) is a novel principle for interpreting precise spatiotemporal coordination in living cells through biomolecular condensate (BMC) formation via dynamic aggregation. LLPS changes individual molecules into membrane-free, droplet-like BMCs with specific functions, which coordinate various cellular activities. The formation and regulation of LLPS are closely associated with oncogenesis, tumor progressions and metastasis, the specific roles and mechanisms of LLPS in tumors still need to be further investigated at present. In this review, we comprehensively summarize the conditions of LLPS and identify mechanisms involved in abnormal LLPS in cancer processes, including tumor growth, metastasis, and angiogenesis from the perspective of cancer hallmarks. We have also reviewed the clinical applications of LLPS in oncologic areas. This systematic summary of dysregulated LLPS from the different dimensions of cancer hallmarks will build a bridge for determining its specific functions to further guide basic research, finding strategies to intervene in LLPS, and developing relevant therapeutic approaches.
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Affiliation(s)
- Le-Wei Zheng
- Department of Breast Surgery, Department of Oncology, Key Laboratory of Breast Cancer in Shanghai, Cancer Institute, Fudan University Shanghai Cancer Center, Shanghai Medical College, Fudan University, Shanghai, 200032, China
| | - Cui-Cui Liu
- Department of Breast Surgery, Department of Oncology, Key Laboratory of Breast Cancer in Shanghai, Cancer Institute, Fudan University Shanghai Cancer Center, Shanghai Medical College, Fudan University, Shanghai, 200032, China
| | - Ke-Da Yu
- Department of Breast Surgery, Department of Oncology, Key Laboratory of Breast Cancer in Shanghai, Cancer Institute, Fudan University Shanghai Cancer Center, Shanghai Medical College, Fudan University, Shanghai, 200032, China.
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Zhang X, Zheng R, Li Z, Ma J. Liquid-liquid Phase Separation in Viral Function. J Mol Biol 2023; 435:167955. [PMID: 36642156 DOI: 10.1016/j.jmb.2023.167955] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 01/04/2023] [Accepted: 01/07/2023] [Indexed: 01/15/2023]
Abstract
An emerging set of results suggests that liquid-liquid phase separation (LLPS) is the basis for the formation of membrane-less compartments in cells. Evidence is now mounting that various types of virus-induced membrane-less compartments and organelles are also assembled via LLPS. Specifically, viruses appear to use intracellular phase transitions to form subcellular microenvironments known as viral factories, inclusion bodies, or viroplasms. These compartments - collectively referred to as viral biomolecular condensates - can be used to concentrate replicase proteins, viral genomes, and host proteins that are required for virus replication. They can also be used to subvert or avoid the intracellular immune response. This review examines how certain DNA or RNA viruses drive the formation of viral condensates, the possible biological functions of those condensates, and the biophysical and biochemical basis for their assembly.
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Affiliation(s)
- Xiaoyue Zhang
- NHC Key Laboratory of Carcinogenesis, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China; Cancer Research Institute and School of Basic Medical Science, Central South University, Changsha, China; Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Hunan Key Laboratory of Nonresolving Inflammation and Cancer, Changsha, China
| | - Run Zheng
- Cancer Research Institute and School of Basic Medical Science, Central South University, Changsha, China; Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Hunan Key Laboratory of Nonresolving Inflammation and Cancer, Changsha, China
| | - Zhengshuo Li
- Cancer Research Institute and School of Basic Medical Science, Central South University, Changsha, China; Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Hunan Key Laboratory of Nonresolving Inflammation and Cancer, Changsha, China
| | - Jian Ma
- NHC Key Laboratory of Carcinogenesis, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China; Cancer Research Institute and School of Basic Medical Science, Central South University, Changsha, China; Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Hunan Key Laboratory of Nonresolving Inflammation and Cancer, Changsha, China.
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Borkosky SS, Fassolari M, Campos-León K, Rossi AH, Salgueiro M, Pascuale CA, Martínez RP, Gaston K, de Prat Gay G. Biomolecular Condensation of the Human Papillomavirus E2 Master Regulator with p53: Implications in Viral Replication. J Mol Biol 2023; 435:167889. [PMID: 36402224 DOI: 10.1016/j.jmb.2022.167889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 10/21/2022] [Accepted: 11/07/2022] [Indexed: 11/18/2022]
Abstract
p53 exerts its tumour suppressor activity by modulating hundreds of genes and it can also repress viral replication. Such is the case of human papillomavirus (HPV) through targeting the E2 master regulator, but the biochemical mechanism is not known. We show that the C-terminal DNA binding domain of HPV16 E2 protein (E2C) triggers heterotypic condensation with p53 at a precise 2/1 E2C/p53 stoichiometry at the onset for demixing, yielding large regular spherical droplets that increase in size with E2C concentration. Interestingly, transfection experiments show that E2 co-localizes with p53 in the nucleus with a grainy pattern, and recruits p53 to chromatin-associated foci, a function independent of the DNA binding capacity of p53 as judged by a DNA binding impaired mutant. Depending on the length, DNA can either completely dissolve or reshape heterotypic droplets into irregular condensates containing p53, E2C, and DNA, and reminiscent of that observed linked to chromatin. We propose that p53 is a scaffold for condensation in line with its structural and functional features, in particular as a promiscuous hub that binds multiple cellular proteins. E2 appears as both client and modulator, likely based on its homodimeric DNA binding nature. Our results, in line with the known role of condensation in eukaryotic gene enhancement and silencing, point at biomolecular condensation of E2 with p53 as a means to modulate HPV gene function, strictly dependent on host cell replication and transcription machinery.
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Affiliation(s)
- Silvia Susana Borkosky
- Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA) - CONICET, Av. Patricias Argentinas 435, 1405 Buenos Aires, Argentina.
| | - Marisol Fassolari
- Fundación para Investigaciones Biológicas Aplicadas (FIBA), Instituto de Investigaciones en Biodiversidad y Biotecnología (INBIOTEC)-CONICET, Mar del Plata, Argentina
| | - Karen Campos-León
- Division of Immunity and Infection, School of Medicine, University of Birmingham, United Kingdom
| | - Andrés Hugo Rossi
- Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA) - CONICET, Av. Patricias Argentinas 435, 1405 Buenos Aires, Argentina
| | - Mariano Salgueiro
- Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA) - CONICET, Av. Patricias Argentinas 435, 1405 Buenos Aires, Argentina
| | - Carla Antonela Pascuale
- Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA) - CONICET, Av. Patricias Argentinas 435, 1405 Buenos Aires, Argentina
| | - Ramón Peralta Martínez
- Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA) - CONICET, Av. Patricias Argentinas 435, 1405 Buenos Aires, Argentina
| | - Kevin Gaston
- School of Medicine, University of Nottingham Biodiscovery Institute, Nottingham, United Kingdom
| | - Gonzalo de Prat Gay
- Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA) - CONICET, Av. Patricias Argentinas 435, 1405 Buenos Aires, Argentina.
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7
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Liu Y, Yao Z, Lian G, Yang P. Biomolecular phase separation in stress granule assembly and virus infection. Acta Biochim Biophys Sin (Shanghai) 2023; 55:1099-1118. [PMID: 37401177 PMCID: PMC10415189 DOI: 10.3724/abbs.2023117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 05/06/2023] [Indexed: 07/05/2023] Open
Abstract
Liquid-liquid phase separation (LLPS) has emerged as a crucial mechanism for cellular compartmentalization. One prominent example of this is the stress granule. Found in various types of cells, stress granule is a biomolecular condensate formed through phase separation. It comprises numerous RNA and RNA-binding proteins. Over the past decades, substantial knowledge has been gained about the composition and dynamics of stress granules. SGs can regulate various signaling pathways and have been associated with numerous human diseases, such as neurodegenerative diseases, cancer, and infectious diseases. The threat of viral infections continues to loom over society. Both DNA and RNA viruses depend on host cells for replication. Intriguingly, many stages of the viral life cycle are closely tied to RNA metabolism in human cells. The field of biomolecular condensates has rapidly advanced in recent times. In this context, we aim to summarize research on stress granules and their link to viral infections. Notably, stress granules triggered by viral infections behave differently from the canonical stress granules triggered by sodium arsenite (SA) and heat shock. Studying stress granules in the context of viral infections could offer a valuable platform to link viral replication processes and host anti-viral responses. A deeper understanding of these biological processes could pave the way for innovative interventions and treatments for viral infectious diseases. They could potentially bridge the gap between basic biological processes and interactions between viruses and their hosts.
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Affiliation(s)
- Yi Liu
- />Westlake Laboratory of Life Sciences and BiomedicineSchool of Life SciencesWestlake UniversityHangzhou310030China
| | - Zhiying Yao
- />Westlake Laboratory of Life Sciences and BiomedicineSchool of Life SciencesWestlake UniversityHangzhou310030China
| | - Guiwei Lian
- />Westlake Laboratory of Life Sciences and BiomedicineSchool of Life SciencesWestlake UniversityHangzhou310030China
| | - Peiguo Yang
- />Westlake Laboratory of Life Sciences and BiomedicineSchool of Life SciencesWestlake UniversityHangzhou310030China
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8
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Schulz TF, Freise A, Stein SC. Kaposi sarcoma-associated herpesvirus latency-associated nuclear antigen: more than a key mediator of viral persistence. Curr Opin Virol 2023; 61:101336. [PMID: 37331160 DOI: 10.1016/j.coviro.2023.101336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 05/03/2023] [Accepted: 05/22/2023] [Indexed: 06/20/2023]
Abstract
Kaposi sarcoma-associated herpesvirus (KSHV), or human herpesvirus-8, is an oncogenic herpesvirus. Its latency-associated nuclear antigen (LANA) is essential for the persistence of KSHV in latently infected cells. LANA mediates replication of the latent viral genome during the S phase of a dividing cell and partitions episomes to daughter cells by attaching them to mitotic chromosomes. It also mediates the establishment of latency in newly infected cells through epigenetic mechanisms and suppresses the activation of the productive replication cycle. Furthermore, LANA promotes the proliferation of infected cell by acting as a transcriptional regulator and by modulating the cellular proteome through the recruitment of several cellular ubiquitin ligases. Finally, LANA interferes with the innate and adaptive immune system to facilitate the immune escape of infected cells.
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Affiliation(s)
- Thomas F Schulz
- Institute of Virology, Hannover Medical School, Germany; Cluster of Excellence 2155 RESIST, Germany; German Center for Infection Research, Hannover-Braunschweig Site, Germany.
| | - Anika Freise
- Institute of Virology, Hannover Medical School, Germany
| | - Saskia C Stein
- Institute of Virology, Hannover Medical School, Germany; Cluster of Excellence 2155 RESIST, Germany
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9
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Vladimirova O, Soldan S, Su C, Kossenkov A, Ngalamika O, Tso FY, West JT, Wood C, Lieberman PM. Elevated iNOS and 3'-nitrotyrosine in Kaposi's Sarcoma tumors and mouse model. Tumour Virus Res 2023; 15:200259. [PMID: 36863485 PMCID: PMC10009278 DOI: 10.1016/j.tvr.2023.200259] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Revised: 01/24/2023] [Accepted: 02/20/2023] [Indexed: 03/04/2023] Open
Abstract
Kaposi's Sarcoma (KS) is a heterogenous, multifocal vascular malignancy caused by the human herpesvirus 8 (HHV8), also known as Kaposi's Sarcoma-Associated Herpesvirus (KSHV). Here, we show that KS lesions express iNOS/NOS2 broadly throughout KS lesions, with enrichment in LANA positive spindle cells. The iNOS byproduct 3-nitrotyrosine is also enriched in LANA positive tumor cells and colocalizes with a fraction of LANA-nuclear bodies. We show that iNOS is highly expressed in the L1T3/mSLK tumor model of KS. iNOS expression correlated with KSHV lytic cycle gene expression, which was elevated in late-stage tumors (>4 weeks) but to a lesser degree in early stage (1 week) xenografts. Further, we show that L1T3/mSLK tumor growth is sensitive to an inhibitor of nitric oxide, L-NMMA. L-NMMA treatment reduced KSHV gene expression and perturbed cellular gene pathways relating to oxidative phosphorylation and mitochondrial dysfunction. These finding suggest that iNOS is expressed in KSHV infected endothelial-transformed tumor cells in KS, that iNOS expression depends on tumor microenvironment stress conditions, and that iNOS enzymatic activity contributes to KS tumor growth.
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Affiliation(s)
| | | | - Chenhe Su
- The Wistar Institute, Philadelphia, PA, 19104, USA
| | | | - Owen Ngalamika
- Dermatology and Venereology Section, University Teaching Hospitals, University of Zambia School of Medicine, Lusaka, P.O. Box 50110, Zambia
| | - For Yue Tso
- Department of Interdisciplinary Oncology, Stanley S Scott Cancer Center, State University Health Sciences Center, New Orleans, LA, USA
| | - John T West
- Department of Interdisciplinary Oncology, Stanley S Scott Cancer Center, State University Health Sciences Center, New Orleans, LA, USA
| | - Charles Wood
- Department of Interdisciplinary Oncology, Stanley S Scott Cancer Center, State University Health Sciences Center, New Orleans, LA, USA
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Yang S, Shen W, Hu J, Cai S, Zhang C, Jin S, Guan X, Wu J, Wu Y, Cui J. Molecular mechanisms and cellular functions of liquid-liquid phase separation during antiviral immune responses. Front Immunol 2023; 14:1162211. [PMID: 37251408 PMCID: PMC10210139 DOI: 10.3389/fimmu.2023.1162211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 04/25/2023] [Indexed: 05/31/2023] Open
Abstract
Spatiotemporal separation of cellular components is vital to ensure biochemical processes. Membrane-bound organelles such as mitochondria and nuclei play a major role in isolating intracellular components, while membraneless organelles (MLOs) are accumulatively uncovered via liquid-liquid phase separation (LLPS) to mediate cellular spatiotemporal organization. MLOs orchestrate various key cellular processes, including protein localization, supramolecular assembly, gene expression, and signal transduction. During viral infection, LLPS not only participates in viral replication but also contributes to host antiviral immune responses. Therefore, a more comprehensive understanding of the roles of LLPS in virus infection may open up new avenues for treating viral infectious diseases. In this review, we focus on the antiviral defense mechanisms of LLPS in innate immunity and discuss the involvement of LLPS during viral replication and immune evasion escape, as well as the strategy of targeting LLPS to treat viral infectious diseases.
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Affiliation(s)
- Shuai Yang
- The First Affiliated Hospital of Sun Yat-sen University, Ministry of Education MOE Key Laboratory of Gene Function and Regulation, School of Life Sciences, Sun Yat-sen University, Guangzhou, Guangdong, China
- Ministry of Education Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Weishan Shen
- Department of Critical Care Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Jiajia Hu
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Sihui Cai
- Ministry of Education Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Chenqiu Zhang
- Ministry of Education Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Shouheng Jin
- Ministry of Education Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Xiangdong Guan
- Department of Critical Care Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Jianfeng Wu
- Department of Critical Care Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Yaoxing Wu
- The First Affiliated Hospital of Sun Yat-sen University, Ministry of Education MOE Key Laboratory of Gene Function and Regulation, School of Life Sciences, Sun Yat-sen University, Guangzhou, Guangdong, China
- Department of Critical Care Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Jun Cui
- The First Affiliated Hospital of Sun Yat-sen University, Ministry of Education MOE Key Laboratory of Gene Function and Regulation, School of Life Sciences, Sun Yat-sen University, Guangzhou, Guangdong, China
- Ministry of Education Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
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11
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Xie Q, Cheng J, Mei W, Yang D, Zhang P, Zeng C. Phase separation in cancer at a glance. J Transl Med 2023; 21:237. [PMID: 37005672 PMCID: PMC10067312 DOI: 10.1186/s12967-023-04082-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 03/25/2023] [Indexed: 04/04/2023] Open
Abstract
Eukaryotic cells are segmented into multiple compartments or organelles within the cell that regulate distinct chemical and biological processes. Membrane-less organelles are membrane-less microscopic cellular compartments that contain protein and RNA molecules that perform a wide range of functions. Liquid-liquid phase separation (LLPS) can reveal how membrane-less organelles develop via dynamic biomolecule assembly. LLPS either segregates undesirable molecules from cells or aggregates desired ones in cells. Aberrant LLPS results in the production of abnormal biomolecular condensates (BMCs), which can cause cancer. Here, we explore the intricate mechanisms behind the formation of BMCs and its biophysical properties. Additionally, we discuss recent discoveries related to biological LLPS in tumorigenesis, including aberrant signaling and transduction, stress granule formation, evading growth arrest, and genomic instability. We also discuss the therapeutic implications of LLPS in cancer. Understanding the concept and mechanism of LLPS and its role in tumorigenesis is crucial for antitumor therapeutic strategies.
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Affiliation(s)
- Qingqing Xie
- Department of Medical Laboratory, Shenzhen Longhua District Central Hospital, Guangdong Medical University, Shenzhen, 518110, China
| | - Jiejuan Cheng
- School of Pharmacy, Hubei University of Science and Technology, Xianning, 437100, Hubei, China
| | - Wuxuan Mei
- Xianning Medical College, Hubei University of Science and Technology, Xianning, 437100, Hubei, China
| | - Dexing Yang
- Department of Medical Laboratory, Shenzhen Longhua District Central Hospital, Guangdong Medical University, Shenzhen, 518110, China
| | - Pengfei Zhang
- Department of Medical Laboratory, Shenzhen Longhua District Central Hospital, Guangdong Medical University, Shenzhen, 518110, China
| | - Changchun Zeng
- Department of Medical Laboratory, Shenzhen Longhua District Central Hospital, Guangdong Medical University, Shenzhen, 518110, China.
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13
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Luo Y, Xiang S, Feng J. Protein Phase Separation: New Insights into Carcinogenesis. Cancers (Basel) 2022; 14:cancers14235971. [PMID: 36497453 PMCID: PMC9740862 DOI: 10.3390/cancers14235971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Revised: 11/29/2022] [Accepted: 12/01/2022] [Indexed: 12/12/2022] Open
Abstract
Phase separation is now acknowledged as an essential biologic mechanism wherein distinct activated molecules assemble into a different phase from the surrounding constituents of a cell. Condensates formed by phase separation play an essential role in the life activities of various organisms under normal physiological conditions, including the advanced structure and regulation of chromatin, autophagic degradation of incorrectly folded or unneeded proteins, and regulation of the actin cytoskeleton. During malignant transformation, abnormally altered condensate assemblies are often associated with the abnormal activation of oncogenes or inactivation of tumor suppressors, resulting in the promotion of the carcinogenic process. Thus, understanding the role of phase separation in various biological evolutionary processes will provide new ideas for the development of drugs targeting specific condensates, which is expected to be an effective cancer therapy strategy. However, the relationship between phase separation and cancer has not been fully elucidated. In this review, we mainly summarize the main processes and characteristics of phase separation and the main methods for detecting phase separation. In addition, we summarize the cancer proteins and signaling pathways involved in phase separation and discuss their promising future applications in addressing the unmet clinical therapeutic needs of people with cancer. Finally, we explain the means of targeted phase separation and cancer treatment.
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Mitrea DM, Mittasch M, Gomes BF, Klein IA, Murcko MA. Modulating biomolecular condensates: a novel approach to drug discovery. Nat Rev Drug Discov 2022; 21:841-862. [PMID: 35974095 PMCID: PMC9380678 DOI: 10.1038/s41573-022-00505-4] [Citation(s) in RCA: 73] [Impact Index Per Article: 36.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/08/2022] [Indexed: 12/12/2022]
Abstract
In the past decade, membraneless assemblies known as biomolecular condensates have been reported to play key roles in many cellular functions by compartmentalizing specific proteins and nucleic acids in subcellular environments with distinct properties. Furthermore, growing evidence supports the view that biomolecular condensates often form by phase separation, in which a single-phase system demixes into a two-phase system consisting of a condensed phase and a dilute phase of particular biomolecules. Emerging understanding of condensate function in normal and aberrant cellular states, and of the mechanisms of condensate formation, is providing new insights into human disease and revealing novel therapeutic opportunities. In this Perspective, we propose that such insights could enable a previously unexplored drug discovery approach based on identifying condensate-modifying therapeutics (c-mods), and we discuss the strategies, techniques and challenges involved.
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Peng Q, Tan S, Xia L, Wu N, Oyang L, Tang Y, Su M, Luo X, Wang Y, Sheng X, Zhou Y, Liao Q. Phase separation in Cancer: From the Impacts and Mechanisms to Treatment potentials. Int J Biol Sci 2022; 18:5103-5122. [PMID: 35982902 PMCID: PMC9379413 DOI: 10.7150/ijbs.75410] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 07/16/2022] [Indexed: 12/14/2022] Open
Abstract
Cancer is a public health problem of great concern, and it is also one of the main causes of death in the world. Cancer is a disease characterized by dysregulation of diverse cellular processes, including avoiding growth inhibitory factors, avoiding immune damage and promoting metastasis, etc. However, the precise mechanism of tumorigenesis and tumor progression still needs to be further elucidated. Formations of liquid-liquid phase separation (LLPS) condensates are a common strategy for cells to achieve diverse functions, such as chromatin organization, signal transduction, DNA repair and transcriptional regulation, etc. The biomolecular aggregates formed by LLPS are mainly driven by multivalent weak interactions mediated by intrinsic disordered regions (IDRs) in proteins. In recent years, aberrant phase separations and transition have been reported to be related to the process of various diseases, such as neurodegenerative diseases and cancer. Herein, we discussed recent findings that phase separation regulates tumor-related signaling pathways and thus contributes to tumor progression. We also reviewed some tumor virus-associated proteins to regulate the development of virus-associated tumors via phase separation. Finally, we discussed some possible strategies for treating tumors by targeting phase separation.
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Affiliation(s)
- Qiu Peng
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, Hunan, China
| | - Shiming Tan
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, Hunan, China
| | - Longzheng Xia
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, Hunan, China
| | - Nayiyuan Wu
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, Hunan, China
| | - Linda Oyang
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, Hunan, China
| | - Yanyan Tang
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, Hunan, China
| | - Min Su
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, Hunan, China
| | - Xia Luo
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, Hunan, China
| | - Ying Wang
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, Hunan, China
| | - Xiaowu Sheng
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, Hunan, China
| | - Yujuan Zhou
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, Hunan, China.,Hunan Key Laboratory of Translational Radiation Oncology, 283 Tongzipo Road, Changsha 410013, Hunan, China
| | - Qianjin Liao
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, Hunan, China.,Hunan Key Laboratory of Translational Radiation Oncology, 283 Tongzipo Road, Changsha 410013, Hunan, China
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Caragliano E, Brune W, Bosse JB. Herpesvirus Replication Compartments: Dynamic Biomolecular Condensates? Viruses 2022; 14:960. [PMID: 35632702 PMCID: PMC9147375 DOI: 10.3390/v14050960] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 04/29/2022] [Accepted: 05/01/2022] [Indexed: 02/01/2023] Open
Abstract
Recent progress has provided clear evidence that many RNA-viruses form cytoplasmic biomolecular condensates mediated by liquid-liquid phase separation to facilitate their replication. In contrast, seemingly contradictory data exist for herpesviruses, which replicate their DNA genomes in nuclear membrane-less replication compartments (RCs). Here, we review the current literature and comment on nuclear condensate formation by herpesviruses, specifically with regard to RC formation. Based on data obtained with human cytomegalovirus (human herpesvirus 5), we propose that liquid and homogenous early RCs convert into more heterogeneous RCs with complex properties over the course of infection. We highlight how the advent of DNA replication leads to the maturation of these biomolecular condensates, likely by adding an additional DNA scaffold.
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Affiliation(s)
- Enrico Caragliano
- Leibniz Institute for Experimental Virology (HPI), 20251 Hamburg, Germany;
- Centre for Structural Systems Biology, 22607 Hamburg, Germany
- Institute of Virology, Hannover Medical School, 30625 Hannover, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, 30625 Hannover, Germany
| | - Wolfram Brune
- Leibniz Institute for Experimental Virology (HPI), 20251 Hamburg, Germany;
- German Center for Infection Research (DZIF), Partner Site Hamburg-Lübeck-Borstel-Riems, 38124 Braunschweig, Germany
| | - Jens B. Bosse
- Leibniz Institute for Experimental Virology (HPI), 20251 Hamburg, Germany;
- Centre for Structural Systems Biology, 22607 Hamburg, Germany
- Institute of Virology, Hannover Medical School, 30625 Hannover, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, 30625 Hannover, Germany
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Caragliano E, Bonazza S, Frascaroli G, Tang J, Soh TK, Grünewald K, Bosse JB, Brune W. Human cytomegalovirus forms phase-separated compartments at viral genomes to facilitate viral replication. Cell Rep 2022; 38:110469. [PMID: 35263605 PMCID: PMC8924372 DOI: 10.1016/j.celrep.2022.110469] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 11/29/2021] [Accepted: 02/10/2022] [Indexed: 12/21/2022] Open
Abstract
Human cytomegalovirus (HCMV) replicates its DNA genome in specialized replication compartments (RCs) in the host cell nucleus. These membrane-less organelles originate as spherical structures and grow in size over time. However, the mechanism of RC biogenesis has remained understudied. Using live-cell imaging and photo-oligomerization, we show that a central component of RCs, the UL112-113 proteins, undergo liquid-liquid phase separation (LLPS) to form RCs in the nucleus. We show that the self-interacting domain and large intrinsically disordered regions of UL112-113 are required for LLPS. Importantly, viral DNA induces local clustering of these proteins and lowers the threshold for phase separation. The formation of phase-separated compartments around viral genomes is necessary to recruit the viral DNA polymerase for viral genome replication. Thus, HCMV uses its UL112-113 proteins to generate RCs around viral genomes by LLPS to ensure the formation of a pro-replicative environment.
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Affiliation(s)
- Enrico Caragliano
- Leibniz Institute for Experimental Virology (HPI), 20251 Hamburg, Germany; Centre for Structural Systems Biology, 22607 Hamburg, Germany; Institute of Virology, Hannover Medical School, 30625 Hannover, Germany
| | - Stefano Bonazza
- Leibniz Institute for Experimental Virology (HPI), 20251 Hamburg, Germany
| | - Giada Frascaroli
- Leibniz Institute for Experimental Virology (HPI), 20251 Hamburg, Germany
| | - Jiajia Tang
- Leibniz Institute for Experimental Virology (HPI), 20251 Hamburg, Germany
| | - Timothy K Soh
- Leibniz Institute for Experimental Virology (HPI), 20251 Hamburg, Germany; Centre for Structural Systems Biology, 22607 Hamburg, Germany; Institute of Virology, Hannover Medical School, 30625 Hannover, Germany; Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany
| | - Kay Grünewald
- Leibniz Institute for Experimental Virology (HPI), 20251 Hamburg, Germany; Centre for Structural Systems Biology, 22607 Hamburg, Germany; Institute of Biochemistry and Molecular Biology, University of Hamburg, 20146 Hamburg, Germany; Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany
| | - Jens B Bosse
- Leibniz Institute for Experimental Virology (HPI), 20251 Hamburg, Germany; Centre for Structural Systems Biology, 22607 Hamburg, Germany; Institute of Virology, Hannover Medical School, 30625 Hannover, Germany; Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany.
| | - Wolfram Brune
- Leibniz Institute for Experimental Virology (HPI), 20251 Hamburg, Germany; German Center for Infection Research (DZIF), Partner Site Hamburg-Lübeck-Borstel-Riems, Hamburg, Germany.
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A panel of KSHV mutants in the polycistronic kaposin locus for precise analysis of individual protein products. J Virol 2021; 96:e0156021. [PMID: 34936820 PMCID: PMC8906436 DOI: 10.1128/jvi.01560-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Kaposi’s sarcoma-associated herpesvirus (KSHV) is the cause of several human cancers, including the endothelial cell (EC) malignancy, Kaposi’s sarcoma. Unique KSHV genes absent from other human herpesvirus genomes, the “K-genes,” are important for KSHV replication and pathogenesis. Among these, the kaposin transcript is highly expressed in all phases of infection, but its complex polycistronic nature has hindered functional analysis to date. At least three proteins are produced from the kaposin transcript: Kaposin A (KapA), B (KapB), and C (KapC). To determine the relative contributions of kaposin proteins during KSHV infection, we created a collection of mutant viruses unable to produce kaposin proteins individually or in combination. In previous work, we showed KapB alone recapitulated the elevated proinflammatory cytokine transcripts associated with KS via the disassembly of RNA granules called processing bodies (PBs). Using the new ΔKapB virus, we showed that KapB was necessary for this effect during latent KSHV infection. Moreover, we observed that despite the ability of all kaposin-deficient latent iSLK cell lines to produce virions, all displayed low viral episome copy number, a defect that became more pronounced after primary infection of naive ECs. For ΔKapB, provision of KapB in trans failed to complement the defect, suggesting a requirement for the kaposin locus in cis. These findings demonstrate that our panel of kaposin-deficient viruses enables precise analysis of the respective contributions of individual kaposin proteins to KSHV replication. Moreover, our mutagenesis approach serves as a guide for the functional analysis of other complex multicistronic viral loci. IMPORTANCE Kaposi’s sarcoma-associated herpesvirus (KSHV) expresses high levels of the kaposin transcript during both latent and lytic phases of replication. Due to its repetitive, GC-rich nature and polycistronic coding capacity, until now no reagents existed to permit a methodical analysis of the role of individual kaposin proteins in KSHV replication. We report the creation of a panel of recombinant viruses and matched producer cell lines that delete kaposin proteins individually or in combination. We demonstrate the utility of this panel by confirming the requirement of one kaposin translation product to a key KSHV latency phenotype. This study describes a new panel of molecular tools for the KSHV field to enable precise analysis of the roles of individual kaposin proteins during KSHV infection.
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Abstract
Viruses have evolved precise mechanisms for using the cellular physiological pathways for their perpetuation. These virus-driven biochemical events must be separated in space and time from those of the host cell. In recent years, granular structures, known for over a century for rabies virus, were shown to host viral gene function and were named using terms such as viroplasms, replication sites, inclusion bodies, or viral factories (VFs). More recently, these VFs were shown to be liquid-like, sharing properties with membrane-less organelles driven by liquid–liquid phase separation (LLPS) in a process widely referred to as biomolecular condensation. Some of the best described examples of these structures come from negative stranded RNA viruses, where micrometer size VFs are formed toward the end of the infectious cycle. We here discuss some basic principles of LLPS in connection with several examples of VFs and propose a view, which integrates viral replication mechanisms with the biochemistry underlying liquid-like organelles. In this view, viral protein and RNA components gradually accumulate up to a critical point during infection where phase separation is triggered. This yields an increase in transcription that leads in turn to increased translation and a consequent growth of initially formed condensates. According to chemical principles behind phase separation, an increase in the concentration of components increases the size of the condensate. A positive feedback cycle would thus generate in which crucial components, in particular nucleoproteins and viral polymerases, reach their highest levels required for genome replication. Progress in understanding viral biomolecular condensation leads to exploration of novel therapeutics. Furthermore, it provides insights into the fundamentals of phase separation in the regulation of cellular gene function given that virus replication and transcription, in particular those requiring host polymerases, are governed by the same biochemical principles.
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