RESUMO
To understand the molecular mechanisms of cellular pathways, contemporary workflows typically require multiple techniques to identify proteins, track their localization, and determine their structures in vitro. Here, we combined cellular cryoelectron tomography (cryo-ET) and AlphaFold2 modeling to address these questions and understand how mammalian sperm are built in situ. Our cellular cryo-ET and subtomogram averaging provided 6.0-Å reconstructions of axonemal microtubule structures. The well-resolved tertiary structures allowed us to unbiasedly match sperm-specific densities with 21,615 AlphaFold2-predicted protein models of the mouse proteome. We identified Tektin 5, CCDC105, and SPACA9 as novel microtubule-associated proteins. These proteins form an extensive interaction network crosslinking the lumen of axonemal doublet microtubules, suggesting their roles in modulating the mechanical properties of the filaments. Indeed, Tekt5 -/- sperm possess more deformed flagella with 180° bends. Together, our studies presented a cellular visual proteomics workflow and shed light on the in vivo functions of Tektin 5.
Assuntos
Proteoma , Espermatozoides , Animais , Masculino , Camundongos , Axonema/química , Microscopia Crioeletrônica/métodos , Flagelos/metabolismo , Microtúbulos/metabolismo , Sêmen , Espermatozoides/química , Proteoma/análiseRESUMO
The nuclear RNA exosome is an essential multi-subunit complex that controls RNA homeostasis. Congenital mutations in RNA exosome genes are associated with neurodegenerative diseases. Little is known about the role of the RNA exosome in the cellular response to pathogens. Here, using NGS and human and mouse genetics, we show that influenza A virus (IAV) ribogenesis and growth are suppressed by impaired RNA exosome activity. Mechanistically, the nuclear RNA exosome coordinates the initial steps of viral transcription with RNAPII at host promoters. The viral polymerase complex co-opts the nuclear RNA exosome complex and cellular RNAs en route to 3' end degradation. Exosome deficiency uncouples chromatin targeting of the viral polymerase complex and the formation of cellular:viral RNA hybrids, which are essential RNA intermediates that license transcription of antisense genomic viral RNAs. Our results suggest that evolutionary arms races have shaped the cellular RNA quality control machinery.
Assuntos
Interações Hospedeiro-Patógeno , Vírus da Influenza A Subtipo H1N1/fisiologia , Vírus da Influenza A Subtipo H3N2/fisiologia , Influenza Humana/virologia , RNA Polimerase II/metabolismo , Células A549 , Animais , Imunoprecipitação da Cromatina , Exorribonucleases/genética , Complexo Multienzimático de Ribonucleases do Exossomo/genética , Exossomos/metabolismo , Humanos , Espectrometria de Massas , Camundongos , Mutação , Doenças Neurodegenerativas/virologia , Proteínas de Ligação a RNA/genética , Ribossomos/genética , Transcrição GênicaRESUMO
A newly described coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is the causative agent of coronavirus disease 2019 (COVID-19), has infected over 2.3 million people, led to the death of more than 160,000 individuals and caused worldwide social and economic disruption1,2. There are no antiviral drugs with proven clinical efficacy for the treatment of COVID-19, nor are there any vaccines that prevent infection with SARS-CoV-2, and efforts to develop drugs and vaccines are hampered by the limited knowledge of the molecular details of how SARS-CoV-2 infects cells. Here we cloned, tagged and expressed 26 of the 29 SARS-CoV-2 proteins in human cells and identified the human proteins that physically associated with each of the SARS-CoV-2 proteins using affinity-purification mass spectrometry, identifying 332 high-confidence protein-protein interactions between SARS-CoV-2 and human proteins. Among these, we identify 66 druggable human proteins or host factors targeted by 69 compounds (of which, 29 drugs are approved by the US Food and Drug Administration, 12 are in clinical trials and 28 are preclinical compounds). We screened a subset of these in multiple viral assays and found two sets of pharmacological agents that displayed antiviral activity: inhibitors of mRNA translation and predicted regulators of the sigma-1 and sigma-2 receptors. Further studies of these host-factor-targeting agents, including their combination with drugs that directly target viral enzymes, could lead to a therapeutic regimen to treat COVID-19.
Assuntos
Betacoronavirus/efeitos dos fármacos , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/metabolismo , Reposicionamento de Medicamentos , Terapia de Alvo Molecular , Pneumonia Viral/tratamento farmacológico , Pneumonia Viral/metabolismo , Mapas de Interação de Proteínas , Proteínas Virais/metabolismo , Animais , Antivirais/classificação , Antivirais/farmacologia , Betacoronavirus/genética , Betacoronavirus/metabolismo , Betacoronavirus/patogenicidade , COVID-19 , Chlorocebus aethiops , Clonagem Molecular , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Avaliação Pré-Clínica de Medicamentos , Células HEK293 , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Humanos , Imunidade Inata , Espectrometria de Massas , Pandemias , Pneumonia Viral/imunologia , Pneumonia Viral/virologia , Ligação Proteica , Biossíntese de Proteínas/efeitos dos fármacos , Domínios Proteicos , Mapeamento de Interação de Proteínas , Receptores sigma/metabolismo , SARS-CoV-2 , Proteínas Ligases SKP Culina F-Box/metabolismo , Células Vero , Proteínas Virais/genética , Tratamento Farmacológico da COVID-19RESUMO
During HIV infection of CD4+ T cells, ubiquitin pathways are essential to viral replication and host innate immune response; however, the role of specific E3 ubiquitin ligases is not well understood. Proteomics analyses identified 116 single-subunit E3 ubiquitin ligases expressed in activated primary human CD4+ T cells. Using a CRISPR-based arrayed spreading infectivity assay, we systematically knocked out 116 E3s from activated primary CD4+ T cells and infected them with NL4-3 GFP reporter HIV-1. We found 10 E3s significantly positively or negatively affected HIV infection in activated primary CD4+ T cells, including UHRF1 (pro-viral) and TRAF2 (anti-viral). Furthermore, deletion of either TRAF2 or UHRF1 in three JLat models of latency spontaneously increased HIV transcription. To verify this effect, we developed a CRISPR-compatible resting primary human CD4+ T cell model of latency. Using this system, we found that deletion of TRAF2 or UHRF1 initiated latency reactivation and increased virus production from primary human resting CD4+ T cells, suggesting these two E3s represent promising targets for future HIV latency reversal strategies. IMPORTANCE: HIV, the virus that causes AIDS, heavily relies on the machinery of human cells to infect and replicate. Our study focuses on the host cell's ubiquitination system which is crucial for numerous cellular processes. Many pathogens, including HIV, exploit this system to enhance their own replication and survival. E3 proteins are part of the ubiquitination pathway that are useful drug targets for host-directed therapies. We interrogated the 116 E3s found in human immune cells known as CD4+ T cells, since these are the target cells infected by HIV. Using CRISPR, a gene-editing tool, we individually removed each of these enzymes and observed the impact on HIV infection in human CD4+ T cells isolated from healthy donors. We discovered that 10 of the E3 enzymes had a significant effect on HIV infection. Two of them, TRAF2 and UHRF1, modulated HIV activity within the cells and triggered an increased release of HIV from previously dormant or "latent" cells in a new primary T cell assay. This finding could guide strategies to perturb hidden HIV reservoirs, a major hurdle to curing HIV. Our study offers insights into HIV-host interactions, identifies new factors that influence HIV infection in immune cells, and introduces a novel methodology for studying HIV infection and latency in human immune cells.
Assuntos
Proteínas Estimuladoras de Ligação a CCAAT , Infecções por HIV , HIV , Fator 2 Associado a Receptor de TNF , Ubiquitina-Proteína Ligases , Latência Viral , Humanos , Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Linfócitos T CD4-Positivos , Sistemas CRISPR-Cas , Fator 2 Associado a Receptor de TNF/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinas/metabolismo , Replicação Viral , HIV/fisiologiaRESUMO
Influenza A Virus (IAV) is a recurring respiratory virus with limited availability of antiviral therapies. Understanding host proteins essential for IAV infection can identify targets for alternative host-directed therapies (HDTs). Using affinity purification-mass spectrometry and global phosphoproteomic and protein abundance analyses using three IAV strains (pH1N1, H3N2, H5N1) in three human cell types (A549, NHBE, THP-1), we map 332 IAV-human protein-protein interactions and identify 13 IAV-modulated kinases. Whole exome sequencing of patients who experienced severe influenza reveals several genes, including scaffold protein AHNAK, with predicted loss-of-function variants that are also identified in our proteomic analyses. Of our identified host factors, 54 significantly alter IAV infection upon siRNA knockdown, and two factors, AHNAK and coatomer subunit COPB1, are also essential for productive infection by SARS-CoV-2. Finally, 16 compounds targeting our identified host factors suppress IAV replication, with two targeting CDK2 and FLT3 showing pan-antiviral activity across influenza and coronavirus families. This study provides a comprehensive network model of IAV infection in human cells, identifying functional host targets for pan-viral HDT.
Assuntos
COVID-19 , Virus da Influenza A Subtipo H5N1 , Vírus da Influenza A , Influenza Humana , Humanos , Vírus da Influenza A/genética , Influenza Humana/genética , Virus da Influenza A Subtipo H5N1/genética , Vírus da Influenza A Subtipo H3N2/metabolismo , Proteômica , Replicação Viral/genética , SARS-CoV-2 , Antivirais/metabolismo , Interações Hospedeiro-Patógeno/genéticaRESUMO
Human Immunodeficiency Virus (HIV) relies on host molecular machinery for replication. Systematic attempts to genetically or biochemically define these host factors have yielded hundreds of candidates, but few have been functionally validated in primary cells. Here, we target 426 genes previously implicated in the HIV lifecycle through protein interaction studies for CRISPR-Cas9-mediated knock-out in primary human CD4+ T cells in order to systematically assess their functional roles in HIV replication. We achieve efficient knockout (>50% of alleles) in 364 of the targeted genes and identify 86 candidate host factors that alter HIV infection. 47 of these factors validate by multiplex gene editing in independent donors, including 23 factors with restrictive activity. Both gene editing efficiencies and HIV-1 phenotypes are highly concordant among independent donors. Importantly, over half of these factors have not been previously described to play a functional role in HIV replication, providing numerous novel avenues for understanding HIV biology. These data further suggest that host-pathogen protein-protein interaction datasets offer an enriched source of candidates for functional host factor discovery and provide an improved understanding of the mechanics of HIV replication in primary T cells.
Assuntos
Infecções por HIV , HIV-1 , Linfócitos T CD4-Positivos/metabolismo , Edição de Genes , HIV-1/genética , Interações entre Hospedeiro e Microrganismos/genética , HumanosRESUMO
Genome engineering of primary human cells with CRISPR-Cas9 has revolutionized experimental and therapeutic approaches to cell biology, but human myeloid-lineage cells have remained largely genetically intractable. We present a method for the delivery of CRISPR-Cas9 ribonucleoprotein (RNP) complexes by nucleofection directly into CD14+ human monocytes purified from peripheral blood, leading to high rates of precise gene knockout. These cells can be efficiently differentiated into monocyte-derived macrophages or dendritic cells. This process yields genetically edited cells that retain transcript and protein markers of myeloid differentiation and phagocytic function. Genetic ablation of the restriction factor SAMHD1 increased HIV-1 infection >50-fold, demonstrating the power of this system for genotype-phenotype interrogation. This fast, flexible, and scalable platform can be used for genetic studies of human myeloid cells in immune signaling, inflammation, cancer immunology, host-pathogen interactions, and beyond, and could facilitate the development of myeloid cellular therapies.
Assuntos
Sistemas CRISPR-Cas/genética , Genoma/genética , Células Mieloides/metabolismo , Ribonucleoproteínas/metabolismo , Animais , Humanos , CamundongosRESUMO
The fate of influenza A virus (IAV) infection in the host cell depends on the balance between cellular defence mechanisms and viral evasion strategies. To illuminate the landscape of IAV cellular restriction, we generated and integrated global genetic loss-of-function screens with transcriptomics and proteomics data. Our multi-omics analysis revealed a subset of both IFN-dependent and independent cellular defence mechanisms that inhibit IAV replication. Amongst these, the autophagy regulator TBC1 domain family member 5 (TBC1D5), which binds Rab7 to enable fusion of autophagosomes and lysosomes, was found to control IAV replication in vitro and in vivo and to promote lysosomal targeting of IAV M2 protein. Notably, IAV M2 was observed to abrogate TBC1D5-Rab7 binding through a physical interaction with TBC1D5 via its cytoplasmic tail. Our results provide evidence for the molecular mechanism utilised by IAV M2 protein to escape lysosomal degradation and traffic to the cell membrane, where it supports IAV budding and growth.
Assuntos
Autofagia , Evasão da Resposta Imune , Vírus da Influenza A/fisiologia , Antivirais/metabolismo , Proteínas Ativadoras de GTPase/genética , Proteínas Ativadoras de GTPase/metabolismo , Interações Hospedeiro-Patógeno , Humanos , Vírus da Influenza A/patogenicidade , Lisossomos/metabolismo , Ligação Proteica , Proteínas da Matriz Viral/metabolismo , Replicação Viral , Proteínas rab de Ligação ao GTP/metabolismo , proteínas de unión al GTP Rab7RESUMO
The COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a grave threat to public health and the global economy. SARS-CoV-2 is closely related to the more lethal but less transmissible coronaviruses SARS-CoV-1 and Middle East respiratory syndrome coronavirus (MERS-CoV). Here, we have carried out comparative viral-human protein-protein interaction and viral protein localization analyses for all three viruses. Subsequent functional genetic screening identified host factors that functionally impinge on coronavirus proliferation, including Tom70, a mitochondrial chaperone protein that interacts with both SARS-CoV-1 and SARS-CoV-2 ORF9b, an interaction we structurally characterized using cryo-electron microscopy. Combining genetically validated host factors with both COVID-19 patient genetic data and medical billing records identified molecular mechanisms and potential drug treatments that merit further molecular and clinical study.
Assuntos
COVID-19/metabolismo , Proteínas do Nucleocapsídeo de Coronavírus/metabolismo , Interações entre Hospedeiro e Microrganismos , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Mapas de Interação de Proteínas , SARS-CoV-2/metabolismo , Síndrome Respiratória Aguda Grave/metabolismo , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/metabolismo , Sequência Conservada , Proteínas do Nucleocapsídeo de Coronavírus/genética , Microscopia Crioeletrônica , Humanos , Proteínas de Transporte da Membrana Mitocondrial/genética , Proteínas do Complexo de Importação de Proteína Precursora Mitocondrial , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Conformação ProteicaRESUMO
An outbreak of the novel coronavirus SARS-CoV-2, the causative agent of COVID-19 respiratory disease, has infected over 290,000 people since the end of 2019, killed over 12,000, and caused worldwide social and economic disruption 1,2 . There are currently no antiviral drugs with proven efficacy nor are there vaccines for its prevention. Unfortunately, the scientific community has little knowledge of the molecular details of SARS-CoV-2 infection. To illuminate this, we cloned, tagged and expressed 26 of the 29 viral proteins in human cells and identified the human proteins physically associated with each using affinity-purification mass spectrometry (AP-MS), which identified 332 high confidence SARS-CoV-2-human protein-protein interactions (PPIs). Among these, we identify 66 druggable human proteins or host factors targeted by 69 existing FDA-approved drugs, drugs in clinical trials and/or preclinical compounds, that we are currently evaluating for efficacy in live SARS-CoV-2 infection assays. The identification of host dependency factors mediating virus infection may provide key insights into effective molecular targets for developing broadly acting antiviral therapeutics against SARS-CoV-2 and other deadly coronavirus strains.
RESUMO
Living organisms have evolved protein phosphorylation, a rapid and versatile mechanism that drives signaling and regulates protein function. We report the phosphoproteomes of 18 fungal species and a phylogenetic-based approach to study phosphosite evolution. We observe rapid divergence, with only a small fraction of phosphosites conserved over hundreds of millions of years. Relative to recently acquired phosphosites, ancient sites are enriched at protein interfaces and are more likely to be functionally important, as we show for sites on H2A1 and eIF4E. We also observe a change in phosphorylation motif frequencies and kinase activities that coincides with the whole-genome duplication event. Our results provide an evolutionary history for phosphosites and suggest that rapid evolution of phosphorylation can contribute strongly to phenotypic diversity.
Assuntos
Evolução Molecular , Proteínas Fúngicas/metabolismo , Fungos/metabolismo , Fosfoproteínas/metabolismo , Processamento de Proteína Pós-Traducional , Sequência de Aminoácidos , Proteínas Fúngicas/classificação , Proteínas Fúngicas/genética , Fungos/genética , Genoma Fúngico , Genômica , Fenótipo , Fosfoproteínas/classificação , Fosfoproteínas/genética , Fosforilação/genética , Filogenia , Proteínas Serina-Treonina Quinases/classificação , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteoma/genética , Proteoma/metabolismo , Transdução de SinaisRESUMO
Triple-negative breast cancer is a heterogeneous disease characterized by poor clinical outcomes and a shortage of targeted treatment options. To discover molecular features of triple-negative breast cancer, we performed quantitative proteomics analysis of twenty human-derived breast cell lines and four primary breast tumors to a depth of more than 12,000 distinct proteins. We used this data to identify breast cancer subtypes at the protein level and demonstrate the precise quantification of biomarkers, signaling proteins, and biological pathways by mass spectrometry. We integrated proteomics data with exome sequence resources to identify genomic aberrations that affect protein expression. We performed a high-throughput drug screen to identify protein markers of drug sensitivity and understand the mechanisms of drug resistance. The genome and proteome provide complementary information that, when combined, yield a powerful engine for therapeutic discovery. This resource is available to the cancer research community to catalyze further analysis and investigation.
Assuntos
Biomarcadores Tumorais/metabolismo , Proteoma/metabolismo , Neoplasias de Mama Triplo Negativas/metabolismo , Antineoplásicos/farmacologia , Biomarcadores Tumorais/genética , Resistencia a Medicamentos Antineoplásicos , Feminino , Ensaios de Triagem em Larga Escala , Humanos , Proteoma/efeitos dos fármacos , Proteoma/genética , Neoplasias de Mama Triplo Negativas/genéticaRESUMO
The field of cellular signaling is fueled by the discovery of novel protein phosphorylation events. Phosphoproteomics focuses on the large-scale identification and characterization of serine, threonine, and tyrosine phosphorylation of proteins. Phosphopeptide enrichment followed by mass spectrometry has emerged as the most powerful technique for unbiased, discovery-driven analysis by offering high sensitivity, resolution, and speed. Methods for mass spectrometry-based phosphoproteomics analysis have improved substantially over the last decade, making the discipline more approachable to the broader scientific community. Herein we describe the status of the field of phosphoproteomics and provide a robust workflow covering the major aspects of large-scale phosphorylation analysis from phosphopeptide enrichment via IMAC to data analysis.