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1.
Nature ; 616(7956): 332-338, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-37020020

RESUMEN

Biomolecular condensates formed by phase separation can compartmentalize and regulate cellular processes1,2. Emerging evidence has suggested that membraneless subcellular compartments in virus-infected cells form by phase separation3-8. Although linked to several viral processes3-5,9,10, evidence that phase separation contributes functionally to the assembly of progeny particles in infected cells is lacking. Here we show that phase separation of the human adenovirus 52-kDa protein has a critical role in the coordinated assembly of infectious progeny particles. We demonstrate that the 52-kDa protein is essential for the organization of viral structural proteins into biomolecular condensates. This organization regulates viral assembly such that capsid assembly is coordinated with the provision of viral genomes needed to produce complete packaged particles. We show that this function is governed by the molecular grammar of an intrinsically disordered region of the 52-kDa protein, and that failure to form condensates or to recruit viral factors that are critical for assembly results in failed packaging and assembly of only non-infectious particles. Our findings identify essential requirements for coordinated assembly of progeny particles and demonstrate that phase separation of a viral protein is critical for production of infectious progeny during adenovirus infection.


Asunto(s)
Adenovirus Humanos , Condensados Biomoleculares , Proteínas Virales , Humanos , Condensados Biomoleculares/química , Condensados Biomoleculares/metabolismo , Cápside/química , Cápside/metabolismo , Proteínas de la Cápside/química , Proteínas de la Cápside/metabolismo , Proteínas Virales/química , Proteínas Virales/metabolismo , Adenovirus Humanos/química , Adenovirus Humanos/crecimiento & desarrollo , Adenovirus Humanos/metabolismo , Proteínas Intrínsecamente Desordenadas/química , Proteínas Intrínsecamente Desordenadas/metabolismo
2.
EMBO J ; 43(2): 277-303, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38177504

RESUMEN

Biomolecular condensates (BMCs) play important roles in diverse biological processes. Many viruses form BMCs which have been implicated in various functions critical for the productive infection of host cells. The adenovirus L1-52/55 kilodalton protein (52K) was recently shown to form viral BMCs that coordinate viral genome packaging and capsid assembly. Although critical for packaging, we do not know how viral condensates are regulated during adenovirus infection. Here we show that phosphorylation of serine residues 28 and 75 within the N-terminal intrinsically disordered region of 52K modulates viral condensates in vitro and in cells, promoting liquid-like properties. Furthermore, we demonstrate that phosphorylation of 52K promotes viral genome packaging and the production of infectious progeny particles. Collectively, our findings provide insights into how viral condensate properties are regulated and maintained in a state conducive to their function in viral progeny production. In addition, our findings have implications for antiviral strategies aimed at targeting the regulation of viral BMCs to limit viral multiplication.


Asunto(s)
Condensados Biomoleculares , Virus , Fosforilación , Proteínas Virales/genética , Proteínas Virales/metabolismo , Replicación Viral
3.
EMBO J ; 2024 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-38886582

RESUMEN

Mutational patterns caused by APOBEC3 cytidine deaminase activity are evident throughout human cancer genomes. In particular, the APOBEC3A family member is a potent genotoxin that causes substantial DNA damage in experimental systems and human tumors. However, the mechanisms that ensure genome stability in cells with active APOBEC3A are unknown. Through an unbiased genome-wide screen, we define the Structural Maintenance of Chromosomes 5/6 (SMC5/6) complex as essential for cell viability when APOBEC3A is active. We observe an absence of APOBEC3A mutagenesis in human tumors with SMC5/6 dysfunction, consistent with synthetic lethality. Cancer cells depleted of SMC5/6 incur substantial genome damage from APOBEC3A activity during DNA replication. Further, APOBEC3A activity results in replication tract lengthening which is dependent on PrimPol, consistent with re-initiation of DNA synthesis downstream of APOBEC3A-induced lesions. Loss of SMC5/6 abrogates elongated replication tracts and increases DNA breaks upon APOBEC3A activity. Our findings indicate that replication fork lengthening reflects a DNA damage response to APOBEC3A activity that promotes genome stability in an SMC5/6-dependent manner. Therefore, SMC5/6 presents a potential therapeutic vulnerability in tumors with active APOBEC3A.

4.
J Virol ; 97(12): e0095523, 2023 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-37991369

RESUMEN

IMPORTANCE: Mutations and genetic rearrangements are the primary driving forces of evolution. Viruses provide valuable model systems for investigating these mechanisms due to their rapid evolutionary rates and vast genetic variability. To investigate genetic rearrangements in the double-stranded DNA genome of herpes simplex virus type 1, the viral population was serially passaged in various cell types. The serial passaging led to formation of defective genomes, resulted from cell-specific non-canonical rearrangements (NCRs). Interestingly, we discovered shared sequence characteristics underlying the formation of these NCRs across all cell types. Moreover, most NCRs identified in clinical samples shared these characteristics. Based on our findings, we propose a model elucidating the formation of NCRs during viral replication within the nucleus of eukaryotic cells.


Asunto(s)
ADN Viral , Genoma Viral , Herpesvirus Humano 1 , Mutación , ADN Viral/genética , Genoma Viral/genética , Herpesvirus Humano 1/genética , Herpesvirus Humano 1/crecimiento & desarrollo , Replicación Viral , Células Eucariotas/virología , Núcleo Celular/virología , Pase Seriado , Humanos
5.
PLoS Pathog ; 18(9): e1010797, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-36095031

RESUMEN

Adenovirus is a common human pathogen that relies on host cell processes for transcription and processing of viral RNA and protein production. Although adenoviral promoters, splice junctions, and polyadenylation sites have been characterized using low-throughput biochemical techniques or short read cDNA-based sequencing, these technologies do not fully capture the complexity of the adenoviral transcriptome. By combining Illumina short-read and nanopore long-read direct RNA sequencing approaches, we mapped transcription start sites and RNA cleavage and polyadenylation sites across the adenovirus genome. In addition to confirming the known canonical viral early and late RNA cassettes, our analysis of splice junctions within long RNA reads revealed an additional 35 novel viral transcripts that meet stringent criteria for expression. These RNAs include fourteen new splice junctions which lead to expression of canonical open reading frames (ORFs), six novel ORF-containing transcripts, and 15 transcripts encoding for messages that could alter protein functions through truncation or fusion of canonical ORFs. In addition, we detect RNAs that bypass canonical cleavage sites and generate potential chimeric proteins by linking distinct gene transcription units. Among these chimeric proteins we detected an evolutionarily conserved protein containing the N-terminus of E4orf6 fused to the downstream DBP/E2A ORF. Loss of this novel protein, E4orf6/DBP, was associated with aberrant viral replication center morphology and poor viral spread. Our work highlights how long-read sequencing technologies combined with mass spectrometry can reveal further complexity within viral transcriptomes and resulting proteomes.


Asunto(s)
Adenoviridae , ARN Viral , Adenoviridae/genética , ADN Complementario , Humanos , Sistemas de Lectura Abierta/genética , Proteoma/metabolismo , Empalme del ARN/genética , ARN Viral/genética , ARN Viral/metabolismo , Proteínas Recombinantes de Fusión/metabolismo , Análisis de Secuencia de ARN/métodos , Transcriptoma
7.
Support Care Cancer ; 32(4): 229, 2024 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-38483623

RESUMEN

BACKGROUND: Up-to-date recommendations for the safe practice of acupuncture in integrative oncology are overdue with new cancer treatments and an increase in survivors with late effects of disease; 17 years have elapsed since Filshie and Hester's 2006 guidelines. During 2022/2023 an expert panel assembled to produce updated recommendations aiming to facilitate safe and appropriate care by acupuncturists working with people with cancer. METHODS: A core development team comprising three integrative oncology professionals comprehensively updated pre-existing unpublished recommendations. Twelve invited international experts (senior acupuncturists with and without experience of working in oncology settings, oncologists, physicians and nurses trained in integrative oncology, researchers, academics, and professional body representatives) reviewed the recommendations. In multiple iterations, the core team harmonised comments for final ratification. To aid dissemination and uptake the panel represents national and international integrative oncology associations and major cancer treatment centres in Europe, USA, Australia, and the Middle East. RESULTS: These recommendations facilitate safe care by articulating contra-indications, cautions, and risks for patients both on and off treatment (surgery, SACT, radiotherapy). Situations where acupuncture may be contra-indicated or practices need adapting are identified. "Red and Amber Flags" highlight where urgent referral is essential. CONCLUSION: These are the first international, multidisciplinary peer-reviewed recommendations for safe acupuncture practice in integrative oncology. Concerns about safety remain a significant barrier to appropriate referral from oncology teams, to use by acupuncturists and to uptake by patients. Disseminating trustworthy, widely accessible guidance should facilitate informed, confident practice of acupuncture in and outside of oncology healthcare settings.


Asunto(s)
Terapia por Acupuntura , Acupuntura , Neoplasias , Humanos , Testimonio de Experto , Neoplasias/terapia , Oncología Médica
8.
Nucleic Acids Res ; 50(3): 1201-1220, 2022 02 22.
Artículo en Inglés | MEDLINE | ID: mdl-34671803

RESUMEN

Eukaryotic cells recognize intracellular pathogens through pattern recognition receptors, including sensors of aberrant nucleic acid structures. Sensors of double-stranded RNA (dsRNA) are known to detect replication intermediates of RNA viruses. It has long been suggested that annealing of mRNA from symmetrical transcription of both top and bottom strands of DNA virus genomes can produce dsRNA during infection. Supporting this hypothesis, nearly all DNA viruses encode inhibitors of dsRNA-recognition pathways. However, direct evidence that DNA viruses produce dsRNA is lacking. Contrary to dogma, we show that the nuclear-replicating DNA virus adenovirus (AdV) does not produce detectable levels of dsRNA during infection. In contrast, abundant dsRNA is detected within the nucleus of cells infected with AdV mutants defective for viral RNA processing. In the presence of nuclear dsRNA, the cytoplasmic dsRNA sensor PKR is relocalized and activated within the nucleus. Accumulation of viral dsRNA occurs in the late phase of infection, when unspliced viral transcripts form intron/exon base pairs between top and bottom strand transcripts. We propose that DNA viruses actively limit dsRNA formation by promoting efficient splicing and mRNA processing, thus avoiding detection and restriction by host innate immune sensors of pathogenic nucleic acids.


Asunto(s)
Adenoviridae , Empalme del ARN , ARN Viral , Adenoviridae/genética , Adenoviridae/metabolismo , ARN Bicatenario/genética , ARN Bicatenario/metabolismo , ARN Mensajero/metabolismo , ARN Viral/genética , ARN Viral/metabolismo
9.
Breast Cancer Res Treat ; 202(2): 287-295, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37612534

RESUMEN

PURPOSE: Chronic musculoskeletal pain is common and debilitating among breast cancer survivors. The PEACE trial demonstrated that electro-acupuncture (EA) and battle field auricular acupuncture (BFAA) both reduced pain more than usual care (UC) in cancer survivors. However, the comparative effectiveness between EA and BFAA among breast cancer survivors is unknown. METHODS: EA and BFAA received ten weekly treatments. UC was offered ten EA treatments after week 12. The primary endpoint was change in mean Brief Pain Inventory (BPI) pain severity from baseline to week 12. We analyzed the subset of 165 (46%) trial participants with a breast cancer primary diagnosis. We conducted constrained linear mixed model analyses, which constrained all arms to a common pre-randomization baseline mean. Model-based mean estimates at weeks 12 and 24 were compared between arms using model contrasts. RESULTS: Among 165 breast cancer survivors, common pre-randomization mean pain severity was 5.35 [95% Confidence Interval (CI) 5.04, 5.66]. At week 12, BPI pain severity score was 2.69 (2.26. 3.13) in EA, 3.60 (3.17, 4.02) in BFAA, and 5.06 (4.47, 5.65) in UC. EA reduced pain severity significantly more than BFAA at weeks 12 [- 0.90 (- 1.45, - 0.36), p = 0.001] and 24 [- 0.82, (- 1.38, - 0.27), p = 0.004]. EA and BFAA significantly improved both Patient-Reported Outcomes Measurement Information System (PROMIS) - Global Health physical health and mental health component scores at week 12 compared to UC. Mild toxicities were reported. CONCLUSION: EA was more effective than BFAA at reducing pain severity, but both similarly improved physical and mental health scores. Breast cancer survivors with chronic musculoskeletal pain may consider EA before BFAA. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02979574. https://clinicaltrials.gov/ct2/show/NCT02979574.


Asunto(s)
Terapia por Acupuntura , Acupuntura Auricular , Neoplasias de la Mama , Supervivientes de Cáncer , Dolor Musculoesquelético , Humanos , Femenino , Neoplasias de la Mama/complicaciones , Neoplasias de la Mama/terapia , Dolor Musculoesquelético/terapia
10.
Bioinformatics ; 38(11): 3113-3115, 2022 05 26.
Artículo en Inglés | MEDLINE | ID: mdl-35426900

RESUMEN

MOTIVATION: The chemical modification of ribonucleotides regulates the structure, stability and interactions of RNAs. Profiling of these modifications using short-read (Illumina) sequencing techniques provides high sensitivity but low-to-medium resolution i.e. modifications cannot be assigned to specific transcript isoforms in regions of sequence overlap. An alternative strategy uses current fluctuations in nanopore-based long read direct RNA sequencing (DRS) to infer the location and identity of nucleotides that differ between two experimental conditions. While highly sensitive, these signal-level analyses require high-quality transcriptome annotations and thus are best suited to the study of model organisms. By contrast, the detection of RNA modifications in microbial organisms which typically have no or low-quality annotations requires an alternative strategy. Here, we demonstrate that signal fluctuations directly influence error rates during base-calling and thus provides an alternative approach for identifying modified nucleotides. RESULTS: DRUMMER (Detection of Ribonucleic acid Modifications Manifested in Error Rates) (i) utilizes a range of statistical tests and background noise correction to identify modified nucleotides with high confidence, (ii) operates with similar sensitivity to signal-level analysis approaches and (iii) correlates very well with orthogonal approaches. Using well-characterized DRS datasets supported by independent meRIP-Seq and miCLIP-Seq datasets we demonstrate that DRUMMER operates with high sensitivity and specificity. AVAILABILITY AND IMPLEMENTATION: DRUMMER is written in Python 3 and is available as open source in the GitHub repository: https://github.com/DepledgeLab/DRUMMER. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Asunto(s)
Secuenciación de Nanoporos , Programas Informáticos , Análisis de Secuencia de ARN/métodos , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , ARN/química , Nucleótidos
11.
EMBO Rep ; 22(9): e52145, 2021 09 06.
Artículo en Inglés | MEDLINE | ID: mdl-34347354

RESUMEN

The APOBEC3 cytidine deaminases are implicated as the cause of a prevalent somatic mutation pattern found in cancer genomes. The APOBEC3 enzymes act as viral restriction factors by mutating viral genomes. Mutation of the cellular genome is presumed to be an off-target activity of the enzymes, although the regulatory measures for APOBEC3 expression and activity remain undefined. It is therefore difficult to predict circumstances that enable APOBEC3 interaction with cellular DNA that leads to mutagenesis. The APOBEC3A (A3A) enzyme is the most potent deaminase of the family. Using proteomics, we evaluate protein interactors of A3A to identify potential regulators. We find that A3A interacts with the chaperonin-containing TCP-1 (CCT) complex, a cellular machine that assists in protein folding and function. Importantly, depletion of CCT results in A3A-induced DNA damage and cytotoxicity. Evaluation of cancer genomes demonstrates an enrichment of A3A mutational signatures in cancers with silencing mutations in CCT subunit genes. Together, these data suggest that the CCT complex interacts with A3A, and that disruption of CCT function results in increased A3A mutational activity.


Asunto(s)
Chaperonina con TCP-1 , Citidina Desaminasa , Chaperonina con TCP-1/genética , Citidina Desaminasa/genética , Mutagénesis , Proteínas/genética
12.
Cell ; 135(1): 49-60, 2008 Oct 03.
Artículo en Inglés | MEDLINE | ID: mdl-18854154

RESUMEN

Human Immunodeficiency Viruses (HIV-1 and HIV-2) rely upon host-encoded proteins to facilitate their replication. Here, we combined genome-wide siRNA analyses with interrogation of human interactome databases to assemble a host-pathogen biochemical network containing 213 confirmed host cellular factors and 11 HIV-1-encoded proteins. Protein complexes that regulate ubiquitin conjugation, proteolysis, DNA-damage response, and RNA splicing were identified as important modulators of early-stage HIV-1 infection. Additionally, over 40 new factors were shown to specifically influence the initiation and/or kinetics of HIV-1 DNA synthesis, including cytoskeletal regulatory proteins, modulators of posttranslational modification, and nucleic acid-binding proteins. Finally, 15 proteins with diverse functional roles, including nuclear transport, prostaglandin synthesis, ubiquitination, and transcription, were found to influence nuclear import or viral DNA integration. Taken together, the multiscale approach described here has uncovered multiprotein virus-host interactions that likely act in concert to facilitate the early steps of HIV-1 infection.


Asunto(s)
Infecciones por VIH/virología , VIH-1/fisiología , Interacciones Huésped-Patógeno , Proteínas/metabolismo , Replicación Viral , Línea Celular , Humanos , Interferencia de ARN , Técnicas del Sistema de Dos Híbridos
13.
J Infect Dis ; 226(9): 1499-1509, 2022 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-35451492

RESUMEN

Herpes simplex virus (HSV) infection of the neonatal brain causes severe encephalitis and permanent neurologic deficits. However, infants infected with HSV at the time of birth follow varied clinical courses, with approximately half of infants experiencing only external infection of the skin rather than invasive neurologic disease. Understanding the cause of these divergent outcomes is essential to developing neuroprotective strategies. To directly assess the contribution of viral variation to neurovirulence, independent of human host factors, we evaluated clinical HSV isolates from neonates with different neurologic outcomes in neurologically relevant in vitro and in vivo models. We found that isolates taken from neonates with encephalitis are more neurovirulent in human neuronal culture and mouse models of HSV encephalitis, as compared to isolates collected from neonates with skin-limited disease. These findings suggest that inherent characteristics of the infecting HSV strain contribute to disease outcome following neonatal infection.


Asunto(s)
Enfermedades Transmisibles , Encefalitis por Herpes Simple , Herpes Simple , Animales , Ratones , Recién Nacido , Humanos , Herpesvirus Humano 2 , Encéfalo
14.
Nature ; 535(7610): 173-7, 2016 07 07.
Artículo en Inglés | MEDLINE | ID: mdl-27362237

RESUMEN

Viral proteins mimic host protein structure and function to redirect cellular processes and subvert innate defenses. Small basic proteins compact and regulate both viral and cellular DNA genomes. Nucleosomes are the repeating units of cellular chromatin and play an important part in innate immune responses. Viral-encoded core basic proteins compact viral genomes, but their impact on host chromatin structure and function remains unexplored. Adenoviruses encode a highly basic protein called protein VII that resembles cellular histones. Although protein VII binds viral DNA and is incorporated with viral genomes into virus particles, it is unknown whether protein VII affects cellular chromatin. Here we show that protein VII alters cellular chromatin, leading us to hypothesize that this has an impact on antiviral responses during adenovirus infection in human cells. We find that protein VII forms complexes with nucleosomes and limits DNA accessibility. We identified post-translational modifications on protein VII that are responsible for chromatin localization. Furthermore, proteomic analysis demonstrated that protein VII is sufficient to alter the protein composition of host chromatin. We found that protein VII is necessary and sufficient for retention in the chromatin of members of the high-mobility-group protein B family (HMGB1, HMGB2 and HMGB3). HMGB1 is actively released in response to inflammatory stimuli and functions as a danger signal to activate immune responses. We showed that protein VII can directly bind HMGB1 in vitro and further demonstrated that protein VII expression in mouse lungs is sufficient to decrease inflammation-induced HMGB1 content and neutrophil recruitment in the bronchoalveolar lavage fluid. Together, our in vitro and in vivo results show that protein VII sequesters HMGB1 and can prevent its release. This study uncovers a viral strategy in which nucleosome binding is exploited to control extracellular immune signaling.


Asunto(s)
Adenoviridae/química , Inmunidad Innata , Nucleosomas/metabolismo , Proteínas del Núcleo Viral/metabolismo , Alarminas/metabolismo , Animales , Líquido del Lavado Bronquioalveolar/citología , Líquido del Lavado Bronquioalveolar/inmunología , Línea Celular , Ensamble y Desensamble de Cromatina/efectos de los fármacos , Proteína HMGB1/metabolismo , Histonas/metabolismo , Humanos , Inmunidad Innata/efectos de los fármacos , Inflamación/inmunología , Inflamación/metabolismo , Pulmón/inmunología , Pulmón/metabolismo , Masculino , Ratones , Infiltración Neutrófila/efectos de los fármacos , Infiltración Neutrófila/inmunología , Nucleosomas/química , Nucleosomas/efectos de los fármacos , Nucleosomas/genética , Unión Proteica , Procesamiento Proteico-Postraduccional , Proteómica , Proteínas del Núcleo Viral/química , Proteínas del Núcleo Viral/farmacología
15.
Oncologist ; 26(11): e2070-e2078, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34390283

RESUMEN

BACKGROUND: Chemotherapy-induced peripheral neuropathy (CIPN) is a common, debilitating adverse effect of neurotoxic chemotherapy that significantly worsens the quality of life of cancer survivors. MATERIALS AND METHODS: Survivors of solid tumors with persistent moderate-to-severe CIPN defined as numbness, tingling, or pain rated ≥4 on an 11-point numeric rating scale (NRS) were randomized in a 1:1:1 ratio to 8 weeks of real acupuncture (RA) versus sham acupuncture (SA) versus usual care (UC). We previously reported the primary endpoint (NRS); here we report the following health-related quality of life endpoints: Functional Assessment of Cancer Therapy/Gynecologic Oncology Group-Neurotoxicity (FACT/GOG-Ntx), Hospital Anxiety and Depression Scale (HADS), Insomnia Severity Index (ISI), and Brief Fatigue Inventory (BFI). For each endpoint, the mean changes from baseline and 95% confidence intervals were estimated within each arm and compared between arms using linear mixed models. RESULTS: We enrolled 75 survivors of solid tumors with moderate-to-severe CIPN into the study. Compared with baseline, at week 8, FACT/GOG-Ntx, HADS anxiety, and ISI scores significantly improved in RA and SA, but not in UC. Compared with UC, at week 8, FACT/GOG-Ntx scores significantly increased in RA and SA arms indicating improved CIPN-related symptoms and quality of life (p = .001 and p = .01). There was no statistically significant difference between RA and SA. There was no difference in HADS depression or BFI among RA, SA, and UC at weeks 8 and 12. CONCLUSION: Acupuncture may improve CIPN-related symptoms and quality of life in cancer survivors with persistent CIPN. Further large sample size studies are needed to delineate placebo effects. IMPLICATIONS FOR PRACTICE: The authors conducted a randomized sham acupuncture- and usual care-controlled clinical trial to evaluate the impact of acupuncture on health-related quality of life outcomes in patients with solid tumors with chemotherapy-induced peripheral neuropathy (CIPN). Statistically significant improvements in quality of life, anxiety, insomnia, and fatigue were achieved with 8 weeks of real acupuncture when compared with baseline, without statistically significant differences between real and sham acupuncture. These findings suggest that acupuncture may be effective for improving CIPN-related symptoms and quality of life and reducing anxiety and insomnia in cancer survivors with persistent CIPN, with further study needed to delineate placebo effects.


Asunto(s)
Terapia por Acupuntura , Antineoplásicos , Supervivientes de Cáncer , Neoplasias , Enfermedades del Sistema Nervioso Periférico , Antineoplásicos/efectos adversos , Femenino , Humanos , Neoplasias/tratamiento farmacológico , Enfermedades del Sistema Nervioso Periférico/inducido químicamente , Calidad de Vida
16.
FASEB J ; 33(8): 9388-9403, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31107607

RESUMEN

Homologous recombination (HR) is considered a major driving force of evolution because it generates and expands genetic diversity. Evidence of HR between coinfecting herpesvirus DNA genomes can be found frequently both in vitro and in clinical isolates. Each herpes simplex virus type 1 (HSV-1) replication compartment (RC) derives from a single incoming genome and maintains a specific territory within the nucleus. This raises intriguing questions about where and when coinfecting viral genomes interact. To study the spatiotemporal requirements for intergenomic recombination, we developed an assay with dual-color FISH that enables detection of HR between different pairs of coinfecting HSV-1 genomes. Our results revealed that HR increases intermingling of RCs derived from different genomes. Furthermore, inhibition of RC movement reduces the rate of HR events among coinfecting viruses. Finally, we observed correlation between nuclear size and the number of RCs per nucleus. Our findings suggest that both viral replication and recombination are subject to nuclear spatial constraints. Other DNA viruses and cellular DNA are likely to encounter similar restrictions.-Tomer, E., Cohen, E. M., Drayman, N., Afriat, A., Weitzman, M. D., Zaritsky, A., Kobiler, O. Coalescing replication compartments provide the opportunity for recombination between coinfecting herpesviruses.


Asunto(s)
Genoma Viral/genética , Herpesvirus Humano 1/genética , Replicación Viral/fisiología , Animales , Línea Celular Tumoral , Chlorocebus aethiops , Replicación del ADN/genética , Replicación del ADN/fisiología , Femenino , Herpesvirus Humano 1/fisiología , Humanos , Hibridación Fluorescente in Situ , Recombinación Genética/genética , Células Vero , Replicación Viral/genética
17.
Mol Cell ; 46(1): 79-90, 2012 Apr 13.
Artículo en Inglés | MEDLINE | ID: mdl-22405594

RESUMEN

Viral hijacking of cellular processes relies on the ability to mimic the structure or function of cellular proteins. Many viruses encode ubiquitin ligases to facilitate infection, although the mechanisms by which they select their substrates are often unknown. The Herpes Simplex Virus type-1-encoded E3 ubiquitin ligase, ICP0, promotes infection through degradation of cellular proteins, including the DNA damage response E3 ligases RNF8 and RNF168. Here we describe a mechanism by which this viral E3 hijacks a cellular phosphorylation-based targeting strategy to degrade RNF8. By mimicking a cellular phosphosite, ICP0 binds RNF8 via the RNF8 forkhead associated (FHA) domain. Phosphorylation of ICP0 T67 by CK1 recruits RNF8 for degradation and thereby promotes viral transcription, replication, and progeny production. We demonstrate that this mechanism may constitute a broader viral strategy to target other cellular factors, highlighting the importance of this region of the ICP0 protein in countering intrinsic antiviral defenses.


Asunto(s)
Proteínas de Unión al ADN/metabolismo , Herpesvirus Humano 1/fisiología , Proteínas Inmediatas-Precoces/metabolismo , Imitación Molecular/fisiología , Proteolisis , Ubiquitina-Proteína Ligasas/metabolismo , Replicación Viral/fisiología , Animales , Chlorocebus aethiops , Proteínas de Unión al ADN/genética , Células HeLa , Humanos , Proteínas Inmediatas-Precoces/genética , Fosforilación , Unión Proteica , Estructura Terciaria de Proteína , Transcripción Genética/fisiología , Ubiquitina-Proteína Ligasas/genética , Células Vero
18.
J Am Chem Soc ; 141(18): 7275-7282, 2019 05 08.
Artículo en Inglés | MEDLINE | ID: mdl-30994345

RESUMEN

Dyes with environment-sensitive fluorescence have proven useful to study the spatiotemporal dynamics of protein activity in living cells. When attached to proteins, their fluorescence can reflect protein conformational changes, post-translational modifications, or protein interactions. However, the utility of such dye-protein conjugates has been limited because it is difficult to load them into cells. They usually must be introduced using techniques that perturb cell physiology, limit throughput, or generate fluorescent vesicles (e.g., electroporation, microinjection, or membrane transduction peptides). Here we circumvent these problems by modifying a proven, environment-sensitive biosensor fluorophore so that it can pass through cell membranes without staining intracellular compartments and can be attached to proteins within living cells using unnatural amino acid (UAA) mutagenesis. Reactive groups were incorporated for attachment to UAAs or small molecules (mero166, azide; mero167, alkyne; mero76, carboxylic acid). These dyes are bright and fluoresce at long wavelengths (reaching ε = 100 000 M-1 cm-1, ϕ = 0.24, with excitation 565 nm and emission 594 nm). The utility of mero166 was demonstrated by in-cell labeling of a UAA to generate a biosensor for the small GTPase Cdc42. In addition, conjugation of mero166 to a small molecule produced a membrane-permeable probe that reported the localization of the DNA methyltransferase G9a in cells. This approach provides a strategy to access biosensors for many targets and to more practically harness the varied environmental sensitivities of synthetic dyes.


Asunto(s)
Benzopiranos/química , Técnicas Biosensibles , Fibroblastos/citología , Colorantes Fluorescentes/química , Indoles/química , Imagen Óptica , Animales , Células HeLa , Humanos , Ratones , Estructura Molecular
19.
Nature ; 503(7477): 525-529, 2013 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-24153179

RESUMEN

Identifying cellular and molecular differences between human and non-human primates (NHPs) is essential to the basic understanding of the evolution and diversity of our own species. Until now, preserved tissues have been the main source for most comparative studies between humans, chimpanzees (Pan troglodytes) and bonobos (Pan paniscus). However, these tissue samples do not fairly represent the distinctive traits of live cell behaviour and are not amenable to genetic manipulation. We propose that induced pluripotent stem (iPS) cells could be a unique biological resource to determine relevant phenotypical differences between human and NHPs, and that those differences could have potential adaptation and speciation value. Here we describe the generation and initial characterization of iPS cells from chimpanzees and bonobos as new tools to explore factors that may have contributed to great ape evolution. Comparative gene expression analysis of human and NHP iPS cells revealed differences in the regulation of long interspersed element-1 (L1, also known as LINE-1) transposons. A force of change in mammalian evolution, L1 elements are retrotransposons that have remained active during primate evolution. Decreased levels of L1-restricting factors APOBEC3B (also known as A3B) and PIWIL2 (ref. 7) in NHP iPS cells correlated with increased L1 mobility and endogenous L1 messenger RNA levels. Moreover, results from the manipulation of A3B and PIWIL2 levels in iPS cells supported a causal inverse relationship between levels of these proteins and L1 retrotransposition. Finally, we found increased copy numbers of species-specific L1 elements in the genome of chimpanzees compared to humans, supporting the idea that increased L1 mobility in NHPs is not limited to iPS cells in culture and may have also occurred in the germ line or embryonic cells developmentally upstream to germline specification during primate evolution. We propose that differences in L1 mobility may have differentially shaped the genomes of humans and NHPs and could have continuing adaptive significance.


Asunto(s)
Elementos de Nucleótido Esparcido Largo/genética , Pan paniscus/genética , Pan troglodytes/genética , Células Madre Pluripotentes/metabolismo , Animales , Proteínas Argonautas/metabolismo , Línea Celular , Forma de la Célula , Citidina Desaminasa/metabolismo , Evolución Molecular , Genoma Humano/genética , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Cariotipificación , Ratones Desnudos , Antígenos de Histocompatibilidad Menor , Pan paniscus/metabolismo , Pan troglodytes/metabolismo , Células Madre Pluripotentes/citología , ARN Mensajero/análisis , ARN Mensajero/genética , Análisis de Secuencia de ARN , Especificidad de la Especie
20.
Mol Cell Proteomics ; 16(4 suppl 1): S92-S107, 2017 04.
Artículo en Inglés | MEDLINE | ID: mdl-28179408

RESUMEN

Herpes simplex virus (HSV-1) lytic infection results in global changes to the host cell proteome and the proteins associated with host chromatin. We present a system level characterization of proteome dynamics during infection by performing a multi-dimensional analysis during HSV-1 lytic infection of human foreskin fibroblast (HFF) cells. Our study includes identification and quantification of the host and viral proteomes, phosphoproteomes, chromatin bound proteomes and post-translational modifications (PTMs) on cellular histones during infection. We analyzed proteomes across six time points of virus infection (0, 3, 6, 9, 12 and 15 h post-infection) and clustered trends in abundance using fuzzy c-means. Globally, we accurately quantified more than 4000 proteins, 200 differently modified histone peptides and 9000 phosphorylation sites on cellular proteins. In addition, we identified 67 viral proteins and quantified 571 phosphorylation events (465 with high confidence site localization) on viral proteins, which is currently the most comprehensive map of HSV-1 phosphoproteome. We investigated chromatin bound proteins by proteomic analysis of the high-salt chromatin fraction and identified 510 proteins that were significantly different in abundance during infection. We found 53 histone marks significantly regulated during virus infection, including a steady increase of histone H3 acetylation (H3K9ac and H3K14ac). Our data provide a resource of unprecedented depth for human and viral proteome dynamics during infection. Collectively, our results indicate that the proteome composition of the chromatin of HFF cells is highly affected during HSV-1 infection, and that phosphorylation events are abundant on viral proteins. We propose that our epi-proteomics approach will prove to be important in the characterization of other model infectious systems that involve changes to chromatin composition.


Asunto(s)
Cromatina/virología , Prepucio/virología , Herpes Simple/metabolismo , Herpesvirus Humano 1/metabolismo , Proteómica/métodos , Proteínas Virales/metabolismo , Células Cultivadas , Cromatina/metabolismo , Proteínas Cromosómicas no Histona/metabolismo , Fibroblastos/citología , Fibroblastos/metabolismo , Fibroblastos/virología , Prepucio/citología , Prepucio/metabolismo , Lógica Difusa , Regulación Viral de la Expresión Génica , Células HeLa , Histonas/metabolismo , Humanos , Masculino , Fosforilación , Procesamiento Proteico-Postraduccional
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