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Single-domain antibodies ("nanobodies") derived from the variable region of camelid heavy-chain only antibody variants have proven to be widely useful tools for research, therapeutic, and diagnostic applications. In addition to traditional display techniques, methods to generate nanobodies using direct detection by mass spectrometry and DNA sequencing have been highly effective. However, certain technical challenges have limited widespread application. We have optimized a new pipeline for this approach that greatly improves screening sensitivity, depth of antibody coverage, antigen compatibility, and overall hit rate and affinity. We have applied this improved methodology to generate significantly higher affinity nanobody repertoires against widely used targets in biological research-i.e., GFP, tdTomato, GST, and mouse, rabbit, and goat immunoglobulin G. We have characterized these reagents in affinity isolations and tissue immunofluorescence microscopy, identifying those that are optimal for these particularly demanding applications, and engineering dimeric constructs for ultra-high affinity. This study thus provides new nanobody tools directly applicable to a wide variety of research problems, and improved techniques enabling future nanobody development against diverse targets.
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Nuclear pore complexes play central roles as gatekeepers of RNA and protein transport between the cytoplasm and nucleoplasm. However, their large size and dynamic nature have impeded a full structural and functional elucidation. Here we determined the structure of the entire 552-protein nuclear pore complex of the yeast Saccharomyces cerevisiae at sub-nanometre precision by satisfying a wide range of data relating to the molecular arrangement of its constituents. The nuclear pore complex incorporates sturdy diagonal columns and connector cables attached to these columns, imbuing the structure with strength and flexibility. These cables also tie together all other elements of the nuclear pore complex, including membrane-interacting regions, outer rings and RNA-processing platforms. Inwardly directed anchors create a high density of transport factor-docking Phe-Gly repeats in the central channel, organized into distinct functional units. This integrative structure enables us to rationalize the architecture, transport mechanism and evolutionary origins of the nuclear pore complex.
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Complexo de Proteínas Formadoras de Poros Nucleares/química , Complexo de Proteínas Formadoras de Poros Nucleares/metabolismo , Poro Nuclear/química , Poro Nuclear/metabolismo , Saccharomyces cerevisiae/química , Reagentes de Ligações Cruzadas/química , Espectrometria de Massas , Modelos Moleculares , Estabilidade Proteica , Transporte Proteico , Transporte de RNARESUMO
Picornaviruses are small RNA viruses that hijack host cell machinery to promote their replication. During infection, these viruses express two proteases, 2Apro and 3Cpro, which process viral proteins. They also subvert a number of host functions, including innate immune responses, host protein synthesis, and intracellular transport, by utilizing poorly understood mechanisms for rapidly and specifically targeting critical host proteins. Here, we used proteomic tools to characterize 2Apro interacting partners, functions, and targeting mechanisms. Our data indicate that, initially, 2Apro primarily targets just two cellular proteins: eukaryotic translation initiation factor eIF4G (a critical component of the protein synthesis machinery) and Nup98 (an essential component of the nuclear pore complex, responsible for nucleocytoplasmic transport). The protease appears to employ two different cleavage mechanisms; it likely interacts with eIF3L, utilizing the eIF3 complex to proteolytically access the eIF4G protein but also directly binds and degrades Nup98. This Nup98 cleavage results in only a marginal effect on nuclear import of proteins, while nuclear export of proteins and mRNAs were more strongly affected. Collectively, our data indicate that 2Apro selectively inhibits protein translation, key nuclear export pathways, and cellular mRNA localization early in infection to benefit viral replication at the expense of particular cell functions.
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Peptídeo Hidrolases , Picornaviridae , Fator de Iniciação Eucariótico 4G/metabolismo , Peptídeo Hidrolases/metabolismo , Picornaviridae/enzimologia , Picornaviridae/genética , Proteômica , RNA Mensageiro/metabolismoRESUMO
BACKGROUND: Fetal magnetic resonance imaging (MRI) may reveal sonographically occult ocular abnormalities. When discovered, acquired causes and genetic associations must be sought. OBJECTIVE: We aim to evaluate a fetal cohort with orbit and/or globe malformations to determine whether there are imaging patterns that suggest the underlying cause. MATERIALS AND METHODS: We searched all fetal MRI reports performed at an academic children's hospital over 9 consecutive years for orbit and/or globe abnormalities. Each positive exam and all follow-up MRIs were evaluated for interocular distance, globe size, shape and signal, and brain malformations. Genetic and clinical diagnoses were recorded from the medical record. RESULTS: Seventy-six of 3,085 fetuses (2.5%) were diagnosed with ocular and/or globe abnormalities; 50% had postnatal follow-up MR exams, all confirming the fetal MRI findings. Ninety-two percent (70/76) had concurrent brain malformations. Sixty-seven percent (51/76) were diagnosed with an underlying disorder and 39% of these were genetically proven. The most common diagnoses with ocular globe abnormalities included CHARGE (coloboma of the eye, heart anomaly, choanal atresia, retardation and genital and ear anomalies) syndrome, trisomy 13 syndrome, dystroglycanopathy, holoprosencephaly and diencephalic-mesencephalic junction dysplasia. Genetic diagnoses were more likely with ocular globe abnormalities than isolated orbital abnormalities (P=0.04). Sixty-seven percent of fetuses with ocular calcifications, hemorrhage and/or lens abnormalities had potential maternal risk factors (P=0.03). CONCLUSION: Malformed ocular globes are associated with brain malformations and genetic abnormalities. Ocular calcifications, hemorrhage and/or lens abnormalities may be associated with maternal risk factors. Genetic work-up should be considered when an ocular globe size or shape abnormality is detected.
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Feto , Malformações do Sistema Nervoso , Feminino , Humanos , Gravidez , Feto/anormalidades , Imageamento por Ressonância Magnética/métodos , Diagnóstico Pré-Natal/métodosRESUMO
Protein lysine methylation is one of the most widespread post-translational modifications in the nuclei of eukaryotic cells. Methylated lysines on histones and nonhistone proteins promote the formation of protein complexes that control gene expression and DNA replication and repair. In the cytoplasm, however, the role of lysine methylation in protein complex formation is not well established. Here we report that the cytoplasmic protein chaperone Hsp90 is methylated by the lysine methyltransferase Smyd2 in various cell types. In muscle, Hsp90 methylation contributes to the formation of a protein complex containing Smyd2, Hsp90, and the sarcomeric protein titin. Deficiency in Smyd2 results in the loss of Hsp90 methylation, impaired titin stability, and altered muscle function. Collectively, our data reveal a cytoplasmic protein network that employs lysine methylation for the maintenance and function of skeletal muscle.
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Citoplasma/metabolismo , Proteínas de Choque Térmico HSP90/metabolismo , Histona-Lisina N-Metiltransferase/metabolismo , Músculo Esquelético/metabolismo , Miofibrilas/metabolismo , Animais , Embrião de Galinha , Conectina , Citoplasma/enzimologia , Histona-Lisina N-Metiltransferase/genética , Humanos , Lisina/metabolismo , Metilação , Proteínas Musculares/metabolismo , Miocárdio/metabolismo , Proteínas Quinases/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Peixe-ZebraRESUMO
INTRODUCTION: Historically, heterogeneous outcome assessments have been used to measure recovery of consciousness in patients with disorders of consciousness (DoC) following traumatic brain injury (TBI), making it difficult to compare across studies. To date, however, there is no comprehensive review of clinical outcome assessments that are used in intervention studies of adults with DoC. The objective of this scoping review is to develop a comprehensive inventory of clinical outcome assessments for recovery of consciousness that have been used in clinical studies of adults with DoC following TBI. METHODS AND ANALYSIS: The methodological framework for this review is: (1) identify the research questions, (2) identify relevant studies, (3) select studies, (4) chart the data, (5) collate, summarise and report results and (6) consult stakeholders to drive knowledge translation. We will identify relevant studies by searching the following electronic bibliographic databases: PubMed, Scopus, EMBASE, PsycINFO and The Cochrane Library (including Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials and Cochrane Methodology Register). Criteria for article inclusion are published in the English-language, peer-reviewed studies of interventions aimed at facilitating recovery of consciousness among adults (> 18 years) with DoC following a severe TBI, published from January 1986 to December 2020. Articles meeting inclusion criteria at this stage will undergo a full text review. We will chart the data by applying the WHO International Classification of Functioning, Disability and Health Framework to identify the content areas of clinical outcome assessments. To support knowledge translation efforts, we will involve clinicians and researchers experienced in TBI care throughout the project from conceptualisation of the study through dissemination of results. ETHICS AND DISSEMINATION: No ethical approval is required for this study as it is not determined to be human subjects research. Results will be presented at national conferences and published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: CRD42017058383.
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Lesões Encefálicas Traumáticas , Estado de Consciência , Adulto , Humanos , Avaliação de Resultados em Cuidados de Saúde , Revisão por Pares , Projetos de Pesquisa , Literatura de Revisão como Assunto , Revisões Sistemáticas como AssuntoRESUMO
OBJECTIVE: We assessed the relationship between ultraviolet (UV)-associated dermatological carcinomas (basal cell carcinoma [BCC] and squamous cell carcinoma [SCC]) and exfoliation syndrome (XFS) or exfoliation glaucoma (XFG). DESIGN: Case-control study. PARTICIPANTS: Between 2019 and 2021, 321 participants and control subjects (XFS or XFG = 98; primary open-angle glaucoma [POAG] = 117; controls = 106; ages 50-90 years) were recruited. METHODS: A cross-sectional survey assessing medical history, maximum known intraocular pressure, cup-to-disc ratio, Humphrey visual field 24-2, the propensity to tan or burn in early life, history of BCC or SCC, and XFS or XFG diagnosis. The multivariable models adjusted for age, sex, medical history, eye color, hair color, and likeliness of tanning versus burning at a young age. MAIN OUTCOME MEASURES: History of diagnosed XFS or XFG. RESULTS: Any history of BCC or SCC in the head and neck region was associated with a 2-fold higher risk of having XFS or XFG versus having POAG or being a control subject (odds ratio [OR], 2.01; 95% confidence interval [CI], 1.04-3.89) in a multivariable-adjusted analysis. We observed a dose-response association in which the chance of having XFS or XFG increased by 67% per head and neck BCC or SCC occurrence (OR, 1.67; 95% CI, 1.09-2.56). When we excluded POAG participants, head and neck BCC or SCC was associated with a 2.8-fold higher risk of XFS or XFG (OR, 2.80; 95% CI, 1.12-7.02), and each additional occurrence had a 2-fold higher risk of XFS or XFG (OR, 1.97; 95% CI, 1.09-3.58). The association between head and neck region BCC or SCC and POAG compared with the control subjects was null (OR, 1.42; 95% CI, 0.58-3.48). With BCC or SCC located anywhere on the body, there was a nonsignificantly higher risk of having XFS or XFG compared with having POAG or being a control subject (OR, 1.65; 95% CI, 0.88-3.09). CONCLUSIONS: Head and neck region BCCs or SCCs are associated with a higher risk of having XFS or XFG. These findings support prior evidence that head and neck UV exposure may be a risk factor for XFS.
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Síndrome de Exfoliação , Glaucoma de Ângulo Aberto , Neoplasias , Humanos , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Síndrome de Exfoliação/complicações , Síndrome de Exfoliação/diagnóstico , Síndrome de Exfoliação/epidemiologia , Glaucoma de Ângulo Aberto/diagnóstico , Estudos de Casos e Controles , Estudos Transversais , Neoplasias/complicaçõesRESUMO
BACKGROUND: The growing population of patients over the age of 65 faces particular vulnerability following discharge after hospitalization or an emergency room visit. Specific areas of concern include a high risk for falls and poor comprehension of discharge instructions. Emergency medical technicians (EMTs), who frequently transport these patients home from the hospital, are uniquely positioned to aid in mitigating transition of care risks and are both trained and utilized to do so using the Transport PLUS intervention. METHODS: Existing literature and focus groups of various stakeholders were utilized to develop two checklists: the fall safety assessment (FSA) and the discharge comprehension assessment (DCA). EMTs were trained to administer the intervention to eligible patients in the geriatric population. Using data from the checklists, follow-up phone calls, and electronic health records, we measured the presence of hazards, removal of hazards, the presence of discharge comprehension issues, and correction or reinforcement of comprehension. These results were validated during home visits by community health workers (CHWs). Feasibility outcomes included patient acceptance of the Transport PLUS intervention and accuracy of the EMT assessment. Qualitative feedback via focus groups was also obtained. Clinical outcomes measured included 3-day and 30-day readmission or ED revisit. RESULTS: One-hundred three EMTs were trained to administer the intervention and participated in 439 patient encounters. The intervention was determined to be feasible, and patients were highly amenable to the intervention, as evidenced by a 92% and 74% acceptance rate of the DCA and FSA, respectively. The majority of patients also reported that they found the intervention helpful (90%) and self-reported removing 40% of fall hazards; 85% of such changes were validated by CHWs. Readmission/revisit rates are also reported. CONCLUSIONS: The Transport PLUS intervention is a feasible, easily implemented tool in preventative community paramedicine with high levels of patient acceptance. Further study is merited to determine the effectiveness of the intervention in reducing rates of readmission or revisit. A randomized control trial has since begun utilizing the knowledge gained within this study.
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Despite the great promise of vaccines, the COVID-19 pandemic is ongoing and future serious outbreaks are highly likely, so that multi-pronged containment strategies will be required for many years. Nanobodies are the smallest naturally occurring single domain antigen binding proteins identified to date, possessing numerous properties advantageous to their production and use. We present a large repertoire of high affinity nanobodies against SARS-CoV-2 Spike protein with excellent kinetic and viral neutralization properties, which can be strongly enhanced with oligomerization. This repertoire samples the epitope landscape of the Spike ectodomain inside and outside the receptor binding domain, recognizing a multitude of distinct epitopes and revealing multiple neutralization targets of pseudoviruses and authentic SARS-CoV-2, including in primary human airway epithelial cells. Combinatorial nanobody mixtures show highly synergistic activities, and are resistant to mutational escape and emerging viral variants of concern. These nanobodies establish an exceptional resource for superior COVID-19 prophylactics and therapeutics.
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The emergence of SARS-CoV-2 variants threatens current vaccines and therapeutic antibodies and urgently demands powerful new therapeutics that can resist viral escape. We therefore generated a large nanobody repertoire to saturate the distinct and highly conserved available epitope space of SARS-CoV-2 spike, including the S1 receptor binding domain, N-terminal domain, and the S2 subunit, to identify new nanobody binding sites that may reflect novel mechanisms of viral neutralization. Structural mapping and functional assays show that indeed these highly stable monovalent nanobodies potently inhibit SARS-CoV-2 infection, display numerous neutralization mechanisms, are effective against emerging variants of concern, and are resistant to mutational escape. Rational combinations of these nanobodies that bind to distinct sites within and between spike subunits exhibit extraordinary synergy and suggest multiple tailored therapeutic and prophylactic strategies.
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COVID-19/imunologia , SARS-CoV-2/imunologia , Anticorpos de Domínio Único/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Sítios de Ligação , Camelídeos Americanos/imunologia , Epitopos/genética , Epitopos/imunologia , Células HEK293 , Humanos , Masculino , Testes de Neutralização , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/genéticaRESUMO
Glaucoma is a neurodegenerative eye disease that results in retinal ganglion cell loss and ultimately loss of vision. Elevated intraocular pressure (IOP) is the most common known risk factor for retinal ganglion cell damage and visual field loss, and the only modifiable risk factor proven to reduce the development and progression of glaucoma. This has greatly influenced our approach and assessment in terms of diagnosis and treatment. However, as many as ≥50% of patients with progressive vision loss from primary open angle glaucoma without IOP elevation (≤22 mm Hg) have been reported in the United States and Canada; 90% in Japan and 80% in Korea. Extensive research is currently underway to identify the etiology of risk factors for glaucoma other than or in addition to elevated IOP (so-called "normal-tension" glaucoma; NTG) and use this knowledge to expand available treatment options. Currently, Food and Drug Administration-approved medications for glaucoma exclusively target elevated IOP, suggesting the need for additional approaches to treatment options beyond the current scope as the definition of glaucoma changes to encompass cellular and molecular mechanisms. This review focuses on alternative medical approaches, specifically Ginkgo Biloba extract, as a potential treatment option for normal-tension glaucoma.
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Pressão Intraocular/fisiologia , Glaucoma de Baixa Tensão/terapia , Extratos Vegetais/farmacologia , Ginkgo biloba , Humanos , Glaucoma de Baixa Tensão/fisiopatologiaRESUMO
U small nuclear RNAs (snRNAs) and mRNAs are both transcribed by RNA polymerase II (Pol II), but the snRNAs have unusual TATA-less promoters and are neither spliced nor polyadenylated; instead, 3' processing is directed by a highly conserved 3' end formation signal that requires initiation from an snRNA promoter. Here we show that the C-terminal domain (CTD) of Pol II is required for efficient U2 snRNA transcription, as it is for mRNA transcription. However, CTD kinase inhibitors, such as 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole (DRB) and 1-(5-isoquinolinesulfonyl)-2-methylpiperazine (H7), that block mRNA elongation do not affect U2 transcription, although 3' processing of the U2 primary transcript is impaired. We show further that U2 transcription is preferentially inhibited by low doses of UV irradiation or actinomycin D, which induce CTD kinase activity, and that UV inhibition can be rescued by treatment with DRB or H7. We propose that Pol II complexes transcribing snRNAs and mRNAs have distinct CTD phosphorylation patterns. mRNA promoters recruit factors including kinases that hyperphosphorylate the CTD, and the CTD in turn recruits proteins needed for mRNA splicing and polyadenylation. We predict that snRNA promoters recruit factors including a CTD kinase(s) whose snRNA-specific phosphorylation pattern recruits factors required for promoter-coupled 3' end formation.
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RNA Polimerase II/metabolismo , RNA Nuclear Pequeno/genética , RNA Nuclear Pequeno/metabolismo , 1-(5-Isoquinolinasulfonil)-2-Metilpiperazina/farmacologia , Sequência de Bases , Linhagem Celular , DNA/genética , Diclororribofuranosilbenzimidazol/farmacologia , Inibidores Enzimáticos/farmacologia , Humanos , Fosforilação , Regiões Promotoras Genéticas , Inibidores de Proteínas Quinases , Proteínas Quinases/metabolismo , Estrutura Terciária de Proteína , RNA Polimerase II/antagonistas & inibidores , RNA Polimerase II/química , Processamento Pós-Transcricional do RNA/efeitos dos fármacos , Processamento Pós-Transcricional do RNA/efeitos da radiação , Transcrição Gênica/efeitos dos fármacos , Transcrição Gênica/efeitos da radiação , Raios UltravioletaRESUMO
Although genetically compact, HIV-1 commandeers vast arrays of cellular machinery to sustain and protect it during cycles of viral outgrowth. Transposon-mediated saturation linker scanning mutagenesis was used to isolate fully replication-competent viruses harbouring a potent foreign epitope tag. Using these viral isolates, we performed differential isotopic labelling and affinity-capture mass spectrometric analyses on samples obtained from cultures of human lymphocytes to classify the vicinal interactomes of the viral Env and Vif proteins as they occur during natural infection. Importantly, interacting proteins were recovered without bias, regardless of their potential for positive, negative or neutral impact on viral replication. We identified specific host associations made with trimerized Env during its biosynthesis, at virological synapses, with innate immune effectors (such as HLA-E) and with certain cellular signalling pathways (for example, Notch1). We also defined Vif associations with host proteins involved in the control of nuclear transcription and nucleoside biosynthesis as well as those interacting stably or transiently with the cytoplasmic protein degradation apparatus. Our approach is broadly applicable to elucidating pathogen-host interactomes, providing high-certainty identification of interactors by their direct access during cycling infection. Understanding the pathophysiological consequences of these associations is likely to provide strategic targets for antiviral intervention.