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1.
Cell ; 187(13): 3357-3372.e19, 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38866018

RESUMO

Microbial hydrogen (H2) cycling underpins the diversity and functionality of diverse anoxic ecosystems. Among the three evolutionarily distinct hydrogenase superfamilies responsible, [FeFe] hydrogenases were thought to be restricted to bacteria and eukaryotes. Here, we show that anaerobic archaea encode diverse, active, and ancient lineages of [FeFe] hydrogenases through combining analysis of existing and new genomes with extensive biochemical experiments. [FeFe] hydrogenases are encoded by genomes of nine archaeal phyla and expressed by H2-producing Asgard archaeon cultures. We report an ultraminimal hydrogenase in DPANN archaea that binds the catalytic H-cluster and produces H2. Moreover, we identify and characterize remarkable hybrid complexes formed through the fusion of [FeFe] and [NiFe] hydrogenases in ten other archaeal orders. Phylogenetic analysis and structural modeling suggest a deep evolutionary history of hybrid hydrogenases. These findings reveal new metabolic adaptations of archaea, streamlined H2 catalysts for biotechnological development, and a surprisingly intertwined evolutionary history between the two major H2-metabolizing enzymes.


Assuntos
Archaea , Hidrogênio , Hidrogenase , Filogenia , Archaea/genética , Archaea/enzimologia , Proteínas Arqueais/metabolismo , Proteínas Arqueais/química , Proteínas Arqueais/genética , Genoma Arqueal , Hidrogênio/metabolismo , Hidrogenase/metabolismo , Hidrogenase/genética , Hidrogenase/química , Proteínas Ferro-Enxofre/metabolismo , Proteínas Ferro-Enxofre/genética , Proteínas Ferro-Enxofre/química , Modelos Moleculares , Estrutura Terciária de Proteína
2.
Nature ; 610(7933): 731-736, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36261517

RESUMO

Anaerobic methane oxidation exerts a key control on greenhouse gas emissions1, yet factors that modulate the activity of microorganisms performing this function remain poorly understood. Here we discovered extraordinarily large, diverse DNA sequences that primarily encode hypothetical proteins through studying groundwater, sediments and wetland soil where methane production and oxidation occur. Four curated, complete genomes are linear, up to approximately 1 Mb in length and share genome organization, including replichore structure, long inverted terminal repeats and genome-wide unique perfect tandem direct repeats that are intergenic or generate amino acid repeats. We infer that these are highly divergent archaeal extrachromosomal elements with a distinct evolutionary origin. Gene sequence similarity, phylogeny and local divergence of sequence composition indicate that many of their genes were assimilated from methane-oxidizing Methanoperedens archaea. We refer to these elements as 'Borgs'. We identified at least 19 different Borg types coexisting with Methanoperedens spp. in four distinct ecosystems. Borgs provide methane-oxidizing Methanoperedens archaea access to genes encoding proteins involved in redox reactions and energy conservation (for example, clusters of multihaem cytochromes and methyl coenzyme M reductase). These data suggest that Borgs might have previously unrecognized roles in the metabolism of this group of archaea, which are known to modulate greenhouse gas emissions, but further studies are now needed to establish their functional relevance.


Assuntos
Methanosarcinales , Aminoácidos/genética , Anaerobiose , Citocromos/genética , Citocromos/metabolismo , Ecossistema , Sedimentos Geológicos , Gases de Efeito Estufa/metabolismo , Metano/metabolismo , Methanosarcinales/classificação , Methanosarcinales/genética , Methanosarcinales/metabolismo , Oxirredução , Filogenia , Solo
3.
PLoS Biol ; 21(1): e3001980, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36701369

RESUMO

Borgs are huge, linear extrachromosomal elements associated with anaerobic methane-oxidizing archaea. Striking features of Borg genomes are pervasive tandem direct repeat (TR) regions. Here, we present six new Borg genomes and investigate the characteristics of TRs in all ten complete Borg genomes. We find that TR regions are rapidly evolving, recently formed, arise independently, and are virtually absent in host Methanoperedens genomes. Flanking partial repeats and A-enriched character constrain the TR formation mechanism. TRs can be in intergenic regions, where they might serve as regulatory RNAs, or in open reading frames (ORFs). TRs in ORFs are under very strong selective pressure, leading to perfect amino acid TRs (aaTRs) that are commonly intrinsically disordered regions. Proteins with aaTRs are often extracellular or membrane proteins, and functionally similar or homologous proteins often have aaTRs composed of the same amino acids. We propose that Borg aaTR-proteins functionally diversify Methanoperedens and all TRs are crucial for specific Borg-host associations and possibly cospeciation.


Assuntos
Archaea , Sequências de Repetição em Tandem , Archaea/genética , Sequências de Repetição em Tandem/genética , Proteínas
4.
PLoS Comput Biol ; 20(2): e1011171, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38306398

RESUMO

Foldy is a cloud-based application that allows non-computational biologists to easily utilize advanced AI-based structural biology tools, including AlphaFold and DiffDock. With many deployment options, it can be employed by individuals, labs, universities, and companies in the cloud without requiring hardware resources, but it can also be configured to utilize locally available computers. Foldy enables scientists to predict the structure of proteins and complexes up to 6000 amino acids with AlphaFold, visualize Pfam annotations, and dock ligands with AutoDock Vina and DiffDock. In our manuscript, we detail Foldy's interface design, deployment strategies, and optimization for various user scenarios. We demonstrate its application through case studies including rational enzyme design and analyzing proteins with domains of unknown function. Furthermore, we compare Foldy's interface and management capabilities with other open and closed source tools in the field, illustrating its practicality in managing complex data and computation tasks. Our manuscript underlines the benefits of Foldy as a day-to-day tool for life science researchers, and shows how Foldy can make modern tools more accessible and efficient.


Assuntos
Proteínas , Software , Humanos , Aminoácidos
5.
BMC Biol ; 22(1): 41, 2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38369453

RESUMO

BACKGROUND: Prior to soil formation, phosphate liberated by rock weathering is often sequestered into highly insoluble lanthanide phosphate minerals. Dissolution of these minerals releases phosphate and lanthanides to the biosphere. Currently, the microorganisms involved in phosphate mineral dissolution and the role of lanthanides in microbial metabolism are poorly understood. RESULTS: Although there have been many studies of soil microbiology, very little research has investigated microbiomes of weathered rock. Here, we sampled weathered granite and associated soil to identify the zones of lanthanide phosphate mineral solubilisation and genomically define the organisms implicated in lanthanide utilisation. We reconstructed 136 genomes from 11 bacterial phyla and found that gene clusters implicated in lanthanide-based metabolism of methanol (primarily xoxF3 and xoxF5) are surprisingly common in microbial communities in moderately weathered granite. Notably, xoxF3 systems were found in Verrucomicrobia for the first time, and in Acidobacteria, Gemmatimonadetes and Alphaproteobacteria. The xoxF-containing gene clusters are shared by diverse Acidobacteria and Gemmatimonadetes, and include conserved hypothetical proteins and transporters not associated with the few well studied xoxF systems. Given that siderophore-like molecules that strongly bind lanthanides may be required to solubilise lanthanide phosphates, it is notable that candidate metallophore biosynthesis systems were most prevalent in bacteria in moderately weathered rock, especially in Acidobacteria with lanthanide-based systems. CONCLUSIONS: Phosphate mineral dissolution, putative metallophore production and lanthanide utilisation by enzymes involved in methanol oxidation linked to carbonic acid production co-occur in the zone of moderate granite weathering. In combination, these microbial processes likely accelerate the conversion of granitic rock to soil.


Assuntos
Elementos da Série dos Lantanídeos , Lantânio , Dióxido de Silício , Elementos da Série dos Lantanídeos/metabolismo , Metanol , Solo , Bactérias/genética , Fosfatos/metabolismo , Minerais/metabolismo
6.
Crit Care Med ; 52(3): 452-463, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-37921513

RESUMO

OBJECTIVES: Although delirium is well described in patients with sepsis, there are limited data on other neurologic complications. We aimed to systematically review the prevalence, neuromonitoring tools, and neurocognitive outcomes in sepsis patients with neurologic complications. DATA SOURCES: MEDLINE and six other databases (Embase, Web of Science, Cochrane CENTRAL, and ClinicalTrials.gov ) were searched through January 2023. STUDY SELECTION: Studies of adult patients with sepsis reported neurologic complications, use of neuromonitoring tools, neuropathology, and cognitive outcomes. DATA EXTRACTION: Two independent reviewers extracted the data. Random-effect meta-analyses were used to pool data. DATA SYNTHESIS: Seventy-four studies ( n = 146,855) were included. Neurologic complications were reported in 38 studies ( n = 142,193) including septic encephalopathy (36%, 95% CI, 27-46%; I 2 = 99%), ischemic stroke (5%, 95% CI, 2.1-11.5; I 2 = 99%), intracranial hemorrhage (2%, 95% CI, 1.0-4.4%; I 2 = 96%), seizures (1%, 95% CI, 0.2-7%; I 2 = 96%), posterior reversible encephalopathy syndrome (9%), and hypoxic-ischemic brain injury (7%). In the meta-regression analysis, pulmonary infection, sepsis induced by a gram-positive organism, higher sequential organ failure assessment score, acute physiology and chronic health evaluation II score at admission, and longer ICU length of stay were associated with higher risk of developing septic encephalopathy. Three studies ( n = 159) reported postmortem neuropathological findings, acute brain injury was noted in 47% of patients. Twenty-six studies ( n = 1,358) reported the use of neuromonitoring tools, electroencephalogram was the most used tool for seizure detection. Transcranial Doppler and near infrared spectroscopy were used for monitoring cerebral hemodynamic changes to detect early ischemia. Six studies reported cognitive outcomes ( n = 415) up to 12 months postdischarge and cognitive impairment (≥ one domain) was reported in 30%. CONCLUSIONS: In-hospital neurologic complications are common in patients with sepsis. However, the mechanism and timing of those sepsis-associated complications are poorly understood and there are limited data on standardized neuromonitoring in this population.


Assuntos
Síndrome da Leucoencefalopatia Posterior , Sepse , Adulto , Humanos , Assistência ao Convalescente , Alta do Paciente , Sepse/complicações , Sepse/epidemiologia , Hospitais
7.
J Am Chem Soc ; 145(16): 8822-8832, 2023 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-37057992

RESUMO

Modular polyketide synthases (PKSs) are polymerases that employ α-carboxyacyl-CoAs as extender substrates. This enzyme family contains several catalytic modules, where each module is responsible for a single round of polyketide chain extension. Although PKS modules typically use malonyl-CoA or methylmalonyl-CoA for chain elongation, many other malonyl-CoA analogues are used to diversify polyketide structures in nature. Previously, we developed a method to alter an extension substrate of a given module by exchanging an acyltransferase (AT) domain while maintaining protein folding. Here, we report in vitro polyketide biosynthesis by 13 PKSs (the wild-type PKS and 12 AT-exchanged PKSs with unusual ATs) and 14 extender substrates. Our ∼200 in vitro reactions resulted in 13 structurally different polyketides, including several polyketides that have not been reported. In some cases, AT-exchanged PKSs produced target polyketides by >100-fold compared to the wild-type PKS. These data also indicate that most unusual AT domains do not incorporate malonyl-CoA and methylmalonyl-CoA but incorporate various rare extender substrates that are equal to in size or slightly larger than natural substrates. We developed a computational workflow to predict the approximate AT substrate range based on active site volumes to support the selection of ATs. These results greatly enhance our understanding of rare AT domains and demonstrate the benefit of using the proposed PKS engineering strategy to produce novel chemicals in vitro.


Assuntos
Policetídeo Sintases , Policetídeos , Policetídeo Sintases/metabolismo , Aciltransferases/química , Domínio Catalítico , Policetídeos/metabolismo , Especificidade por Substrato
8.
Mol Cell Proteomics ; 19(2): 362-374, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31888963

RESUMO

FcγRIIIa (CD16a) and FcγRIIa (CD32a) on monocytes are essential for proper effector functions including antibody dependent cellular cytotoxicity (ADCC) and phagocytosis (ADCP). Indeed, therapeutic monoclonal antibodies (mAbs) that bind FcγRs with greater affinity exhibit greater efficacy. Furthermore, post-translational modification impacts antibody binding affinity, most notably the composition of the asparagine(N)-linked glycan at N162 of CD16a. CD16a is widely recognized as the key receptor for the monocyte response, however the post-translational modifications of CD16a from endogenous monocytes are not described. Here we isolated monocytes from individual donors and characterized the composition of CD16a and CD32a N-glycans from all modified sites. The composition of CD16a N-glycans varied by glycosylation site and donor. CD16a displayed primarily complex-type biantennary N-glycans at N162, however some individuals expressed CD16a V158 with ∼20% hybrid and oligomannose types which increased affinity for IgG1 Fc according to surface plasmon resonance binding analyses. The CD16a N45-glycans contain markedly less processing than other sites with >75% hybrid and oligomannose forms. N38 and N74 of CD16a both contain highly processed complex-type N-glycans with N-acetyllactosamine repeats and complex-type biantennary N-glycans dominate at N169. The composition of CD16a N-glycans isolated from monocytes included a higher proportion of oligomannose-type N-glycans at N45 and less sialylation plus greater branch fucosylation than we observed in a recent analysis of NK cell CD16a. The additional analysis of CD32a from monocytes revealed different features than observed for CD16a including the presence of a predominantly biantennary complex-type N-glycans with two sialic acids at both sites (N64 and N145).


Assuntos
Imunoglobulina G/metabolismo , Monócitos/metabolismo , Polissacarídeos/metabolismo , Receptores de IgG/metabolismo , Glicosilação , Células HEK293 , Humanos
9.
Glycobiology ; 30(7): 427-432, 2020 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-31967297

RESUMO

Fc γ receptor IIIa/CD16a is an activating cell surface receptor with a well-defined role in natural killer (NK) cell and monocyte effector function. The extracellular domain is decorated with five asparagine (N)-linked glycans; N-glycans at N162 and N45 directly contribute to high-affinity antibody binding and protein stability. N-glycan structures at N162 showed significant donor-dependent variation in a recent study of CD16a isolated from primary human NK cells, but structures at N45 were relatively homogeneous. In this study, we identified variations in N45 glycan structures associated with a polymorphism coding for histidine instead of leucine at position 48 of CD16a from two heterozygous donors. It is known that H48 homozygous individuals suffer from immunodeficiency and recurrent viral infections. A mass spectrometry analysis of protein isolated from the primary natural killer cells of individuals expressing both CD16a L48 and H48 variants demonstrated clear processing differences at N45. CD16a H48 displayed a greater proportion of complex-type N45 glycans compared to the more common L48 allotype with predominantly hybrid N45-glycoforms. Structures at the four other N-glycosylation sites showed minimal differences from data collected on donors expressing only the predominant L48 variant. CD16a H48 purified from a pool of monocytes similarly displayed increased processing at N45. Here, we provide evidence that CD16a processing is affected by the H48 residue in primary NK cells and monocytes from healthy human donors.


Assuntos
Células Matadoras Naturais/imunologia , Monócitos/imunologia , Polissacarídeos/imunologia , Receptores de IgG/imunologia , Afinidade de Anticorpos , Humanos , Receptores de IgG/análise
10.
PLoS Pathog ; 14(10): e1007328, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30308062

RESUMO

Streptococcus pneumoniae (pneumococcus) is an opportunistic pathogen that causes otitis media, sinusitis, pneumonia, meningitis and sepsis. The progression to this pathogenic lifestyle is preceded by asymptomatic colonization of the nasopharynx. This colonization is associated with biofilm formation; the competence pathway influences the structure and stability of biofilms. However, the molecules that link the competence pathway to biofilm formation are unknown. Here, we describe a new competence-induced gene, called briC, and demonstrate that its product promotes biofilm development and stimulates colonization in a murine model. We show that expression of briC is induced by the master regulator of competence, ComE. Whereas briC does not substantially influence early biofilm development on abiotic surfaces, it significantly impacts later stages of biofilm development. Specifically, briC expression leads to increases in biofilm biomass and thickness at 72h. Consistent with the role of biofilms in colonization, briC promotes nasopharyngeal colonization in the murine model. The function of BriC appears to be conserved across pneumococci, as comparative genomics reveal that briC is widespread across isolates. Surprisingly, many isolates, including strains from clinically important PMEN1 and PMEN14 lineages, which are widely associated with colonization, encode a long briC promoter. This long form captures an instance of genomic plasticity and functions as a competence-independent expression enhancer that may serve as a precocious point of entry into this otherwise competence-regulated pathway. Moreover, overexpression of briC by the long promoter fully rescues the comE-deletion induced biofilm defect in vitro, and partially in vivo. These findings indicate that BriC may bypass the influence of competence in biofilm development and that such a pathway may be active in a subset of pneumococcal lineages. In conclusion, BriC is a part of the complex molecular network that connects signaling of the competence pathway to biofilm development and colonization.


Assuntos
Proteínas de Bactérias/metabolismo , Biofilmes/crescimento & desenvolvimento , Fragmentos de Peptídeos/metabolismo , Infecções Pneumocócicas/microbiologia , Streptococcus pneumoniae/crescimento & desenvolvimento , Virulência , Sequência de Aminoácidos , Animais , Chinchila , Feminino , Camundongos , Infecções Pneumocócicas/genética , Infecções Pneumocócicas/metabolismo , Regiões Promotoras Genéticas , Homologia de Sequência , Streptococcus pneumoniae/genética , Streptococcus pneumoniae/metabolismo
11.
Mol Ecol ; 29(21): 4074-4090, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32911576

RESUMO

Janzen's influential "mountain passes are higher in the tropics" hypothesis predicts restricted gene flow and genetic isolation among populations spanning elevational gradients in the tropics. Few studies have tested this prediction, and studies that focus on population genetic structure in Southeast Asia are particularly underrepresented in the literature. Here, we test the hypothesis that mountain treeshrews (Tupaia montana) exhibit limited dispersal across their broad elevational range which spans ~2,300 m on two peaks in Kinabalu National Park (KNP) in Borneo: Mt Tambuyukon (MT) and Mt Kinabalu (MK). We sampled 83 individuals across elevations on both peaks and performed population genomics analyses on mitogenomes and single nucleotide polymorphisms from 4,106 ultraconserved element loci. We detected weak genetic structure and infer gene flow both across elevations and between peaks. We found higher genetic differentiation on MT than MK despite its lower elevation and associated environmental variation. This implies that, contrary to our hypothesis, genetic structure in this system is not primarily shaped by elevation. We propose that this pattern may instead be the result of historical processes and limited upslope gene flow on MT. Importantly, our results serve as a foundational estimate of genetic diversity and population structure from which to track potential future effects of climate change on mountain treeshrews in KNP, an important conservation stronghold for the mountain treeshrew and other montane species.


Assuntos
Altitude , Fluxo Gênico , Animais , Bornéu , Estruturas Genéticas , Humanos , Mamíferos
12.
Curr Pain Headache Rep ; 24(9): 52, 2020 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-32705357

RESUMO

PURPOSE OF REVIEW: Sickle cell disease (SCD) remains among the most common and severe monogenic disorders present in the world today. Although sickle cell pain has been traditionally characterized as nociceptive, a significant portion of sickle cell patients has reported neuropathic pain symptoms. Our review article will discuss clinical aspects of SCD-related neuropathic pain, epidemiology of neuropathic pain among individuals with SCD, pain mechanisms, and current and future potential pharmacological interventions. RECENT FINDINGS: Neuropathic pain in SCD is a complicated condition that often has a lifelong and significant negative impact on life; therefore, improved pain management is considered a significant and unmet need. Neuropathic pain mechanisms are heterogeneous, and the difficulty in determining their individual contribution to specific pain types may contribute to poor treatment outcomes in this population. Our review article outlines several pharmacological modalities which may be employed to treat neuropathic pain in SCD patients.


Assuntos
Anemia Falciforme/terapia , Neuralgia/etiologia , Neuralgia/terapia , Manejo da Dor , Anemia Falciforme/complicações , Anemia Falciforme/diagnóstico , Humanos , Neuralgia/complicações , Medição da Dor , Qualidade de Vida , Resultado do Tratamento
13.
J Biol Chem ; 293(51): 19899-19908, 2018 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-30361439

RESUMO

Therapeutic mAbs engage Fc γ receptor III (CD16) to elicit a protective cell-mediated response and destroy the target tissue. Newer drugs designed to bind CD16a with increased affinity surprisingly also elicit protective CD16b-mediated responses. However, it is unclear why IgG binds CD16a with more than 10-fold higher affinity than CD16b even though these receptors share more than 97% identity. Here we identified one residue, Gly-129, that contributes to the greater IgG binding affinity of CD16a. The CD16b variant D129G bound IgG1 Fc with 2-fold higher affinity than CD16a and with 90-fold higher affinity than the WT. Conversely, the binding affinity of CD16a-G129D was decreased 128-fold relative to WT CD16a and comparably to that of WT CD16b. The interaction of IgG1 Fc with CD16a, but not with CD16b, is known to be sensitive to the composition of the asparagine-linked carbohydrates (N-glycans) attached to the receptor. CD16a and CD16b-D129G displaying minimally processed oligomannose N-glycans bound to IgG1 Fc with about 5.2-fold increased affinity compared with variants with highly processed complex-type N-glycans. CD16b and the CD16a-G129D variant exhibited a smaller 1.9-fold affinity increase with oligomannose N-glycans. A model of glycosylated CD16b bound to IgG1 Fc determined to 2.2 Šresolution combined with a 250-ns all-atom molecular dynamics simulation showed that the larger Asp-129 residue deformed the Fc-binding surface. These results reveal how Asp-129 in CD16b affects its binding affinity for IgG1 Fc and suggest that antibodies engineered to engage CD16b with high affinity must accommodate the Asp-129 side chain.


Assuntos
Afinidade de Anticorpos , Imunoglobulina G/imunologia , Receptores de IgG/química , Receptores de IgG/imunologia , Sequência de Aminoácidos , Glicosilação , Células HEK293 , Humanos , Simulação de Dinâmica Molecular , Polissacarídeos/química , Polissacarídeos/metabolismo , Conformação Proteica , Receptores de IgG/metabolismo
14.
J Biol Chem ; 293(10): 3477-3489, 2018 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-29330305

RESUMO

CD16a/Fc γ receptor IIIa is the most abundant antibody Fc receptor expressed on human natural killer (NK) cells and activates a protective cytotoxic response following engagement with antibody clustered on the surface of a pathogen or diseased tissue. Therapeutic monoclonal antibodies (mAbs) with greater Fc-mediated affinity for CD16a show superior therapeutic outcome; however, one significant factor that promotes antibody-CD16a interactions, the asparagine-linked carbohydrates (N-glycans), remains undefined. Here, we purified CD16a from the primary NK cells of three donors and identified a large proportion of hybrid (22%) and oligomannose N-glycans (23%). These proportions indicated restricted N-glycan processing and were unlike those of the recombinant CD16a forms, which have predominantly complex-type N-glycans (82%). Tethering recombinant CD16a to the membrane by including the transmembrane and intracellular domains and via coexpression with the Fc ϵ receptor γ-chain in HEK293F cells was expected to produce N-glycoforms similar to NK cell-derived CD16a but yielded N-glycoforms different from NK cell-derived CD16a and recombinant soluble CD16a. Of note, these differences in CD16a N-glycan composition affected antibody binding: CD16a with oligomannose N-glycans bound IgG1 Fc with 12-fold greater affinity than did CD16a having primarily complex-type and highly branched N-glycans. The changes in binding activity mirrored changes in NMR spectra of the two CD16a glycoforms, indicating that CD16a glycan composition also affects the glycoprotein's structure. These results indicated that CD16a from primary human NK cells is compositionally, and likely also functionally, distinct from commonly used recombinant forms. Furthermore, our study provides critical evidence that cell lineage determines CD16a N-glycan composition and antibody-binding affinity.


Assuntos
Fragmentos Fc das Imunoglobulinas/metabolismo , Células Matadoras Naturais/metabolismo , Modelos Moleculares , Polissacarídeos/metabolismo , Processamento de Proteína Pós-Traducional , Receptores de IgG/metabolismo , Idoso , Anticorpos Monoclonais/química , Anticorpos Monoclonais/genética , Anticorpos Monoclonais/metabolismo , Anticorpos Monoclonais/farmacologia , Sequência de Carboidratos , Linhagem da Célula , Células Cultivadas , Glicosilação , Células HEK293 , Humanos , Fragmentos Fc das Imunoglobulinas/química , Fragmentos Fc das Imunoglobulinas/genética , Células Matadoras Naturais/citologia , Células Matadoras Naturais/efeitos dos fármacos , Células Matadoras Naturais/imunologia , Ligantes , Masculino , Fragmentos de Peptídeos/agonistas , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/metabolismo , Polissacarídeos/química , Conformação Proteica , Domínios e Motivos de Interação entre Proteínas , Receptores de IgG/agonistas , Receptores de IgG/química , Receptores de IgG/genética , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Solubilidade
15.
Mol Microbiol ; 105(4): 554-571, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28557053

RESUMO

Streptococcus pneumoniae (pneumococcus) is a major human pathogen. It is a common colonizer of the human respiratory track, where it utilizes cell-cell communication systems to coordinate population-level behaviors. We reasoned that secreted peptides that are highly expressed during infection are pivotal for virulence. Thus, we used in silico pattern searches to define a pneumococcal secretome and analyzed the transcriptome of the clinically important PMEN1 lineage to identify which peptide-encoding genes are highly expressed in vivo. In this study, we characterized virulence peptide 1 (vp1), a highly expressed Gly-Gly peptide-encoding gene in chinchilla middle ear effusions. The vp1 gene is widely distributed across pneumococcus as well as encoded in related species. Studies in the chinchilla model of middle ear infection demonstrated that VP1 is a virulence determinant. The vp1 gene is positively regulated by a transcription factor from the Rgg family and its cognate SHP (short hydrophobic peptide). In vitro data indicated that VP1 promotes increased thickness and biomass for biofilms grown on chinchilla middle ear epithelial cells. Furthermore, the wild-type biofilm is restored with the exogenous addition of synthetic VP1. We conclude that VP1 is a novel streptococcal regulatory peptide that controls biofilm development and pneumococcal pathogenesis.


Assuntos
Biofilmes/crescimento & desenvolvimento , Streptococcus pneumoniae/metabolismo , Virulência/genética , Animais , Proteínas de Bactérias/metabolismo , Comunicação Celular/fisiologia , Chinchila , Bases de Dados de Ácidos Nucleicos , Orelha Média/microbiologia , Regulação Bacteriana da Expressão Gênica/genética , Otite Média/microbiologia , Peptídeos/metabolismo , Infecções Pneumocócicas/metabolismo , Análise de Sequência de DNA/métodos , Streptococcus/metabolismo , Streptococcus pneumoniae/genética , Fatores de Virulência/genética , Fatores de Virulência/metabolismo
16.
Biol Reprod ; 96(3): 551-562, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28203719

RESUMO

Obesity has been linked with a host of metabolic and reproductive disorders including polycystic ovary syndrome (PCOS). While a clear association exists between obesity and PCOS, the exact nature of this relationship remains unexplained. The primary symptoms of PCOS include hyperandrogenism, anovulation, and polycystic ovaries. Most animal models utilize androgen treatments to induce PCOS. However, these models often fail to address the underlying causes of the disease and do not effectively reproduce key metabolic features such as hyperinsulinemia. Here, we present a novel rodent model of diet-induced obesity that recapitulates both the metabolic and reproductive phenotypes of human PCOS. Rats on a high-fat high-sugar (HFHS) diet not only demonstrated signs of metabolic impairment, but they also developed polycystic ovaries and experienced irregular estrous cycling. Though hyperandrogenism was not characteristic of HFHS animals as a group, elevated testosterone levels were predictive of high numbers of ovarian cysts. Alterations in steroidogenesis and folliculogenesis gene expression were also found via RNA sequencing of ovarian tissue. Importantly, the PCOS-like symptoms induced in these rats may share a similar etiology to PCOS in humans. Therefore, this model offers a unique opportunity to study PCOS at its genesis rather than following the development of disease symptoms.

17.
ACS Synth Biol ; 13(1): 206-219, 2024 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-38113125

RESUMO

In this study, we explored the development of engineered inducible systems. Publicly available data from previous transposon sequencing assays were used to identify regulators of metabolism in Pseudomonas putida KT2440. For AraC family regulators (AFRs) represented in these data, we posited AFR/promoter/inducer groupings. Twelve promoters were characterized for a response to their proposed inducers in P. putida, and the resultant data were used to create and test nine two-plasmid sensor systems in Escherichia coli. Several of these were further developed into a palette of single-plasmid inducible systems. From these experiments, we observed an unreported inducer response from a previously characterized AFR, demonstrated that the addition of a P. putida transporter improved the sensor dynamics of an AFR in E. coli, and identified an uncharacterized AFR with a novel potential inducer specificity. Finally, targeted mutations in an AFR, informed by structural predictions, enabled the further diversification of these inducible plasmids.


Assuntos
Proteínas de Escherichia coli , Pseudomonas putida , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Regiões Promotoras Genéticas/genética , Pseudomonas putida/genética , Pseudomonas putida/metabolismo , Plasmídeos/genética , Regulação Bacteriana da Expressão Gênica/genética , Proteínas de Escherichia coli/genética , Fator de Transcrição AraC/genética
18.
JAMA Cardiol ; 9(4): 397-404, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38381449

RESUMO

Importance: Implementation of guideline-directed medical therapy (GDMT) in real-world practice remains suboptimal. It is unclear which interventions are most effective at addressing current barriers to GDMT in patients with heart failure with reduced ejection fraction (HFrEF). Objective: To perform a systematic review to identify which types of system-level initiatives are most effective at improving GDMT use among patients with HFrEF. Evidence Review: PubMed, Embase, Cochrane, CINAHL, and Web of Science databases were queried from January 2010 to November 2023 for randomized clinical trials that implemented a quality improvement intervention with GDMT use as a primary or secondary outcome. References from related review articles were also included for screening. Quality of studies and bias assessment were graded based on the Cochrane Risk of Bias tool and Oxford Centre for Evidence-Based Medicine. Findings: Twenty-eight randomized clinical trials were included with an aggregate sample size of 19 840 patients. Studies were broadly categorized as interdisciplinary interventions (n = 15), clinician education (n = 5), electronic health record initiatives (n = 6), or patient education (n = 2). Overall, interdisciplinary titration clinics were associated with significant increases in the proportion of patients on target doses of GDMT with a 10% to 60% and 2% to 53% greater proportion of patients on target doses of ß-blockers and renin-angiotensin-aldosterone system inhibitors, respectively, in intervention groups compared with usual care. Other interventions, such as audits, clinician and patient education, or electronic health record alerts, were also associated with some improvements in GDMT utilization, though these findings were inconsistent across studies. Conclusions and Relevance: This review summarizes interventions aimed at optimization of GDMT in clinical practice. Initiatives that used interdisciplinary teams, largely comprised of nurses and pharmacists, most consistently led to improvements in GDMT. Additional large, randomized studies are necessary to better understand other types of interventions, as well as their long-term efficacy and sustainability.


Assuntos
Insuficiência Cardíaca , Disfunção Ventricular Esquerda , Humanos , Insuficiência Cardíaca/tratamento farmacológico , Insuficiência Cardíaca/diagnóstico , Volume Sistólico , Antagonistas Adrenérgicos beta/uso terapêutico , Disfunção Ventricular Esquerda/tratamento farmacológico , Melhoria de Qualidade
19.
Nat Microbiol ; 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38918468

RESUMO

Methane emissions are mitigated by anaerobic methane-oxidizing archaea, including Methanoperedens. Some Methanoperedens host huge extrachromosomal genetic elements (ECEs) called Borgs that may modulate their activity, yet the broader diversity of Methanoperedens ECEs is understudied. Here we report small enigmatic linear ECEs, circular viruses and unclassified ECEs that are predicted to replicate within Methanoperedens. Linear ECEs have inverted terminal repeats, tandem repeats and coding patterns that are strongly reminiscent of Borgs, but they are only 52-145 kb in length. As they share proteins with Borgs and Methanoperedens, we refer to them as mini-Borgs. Mini-Borgs are genetically diverse and can be assigned to at least five family-level groups. We identify eight families of Methanoperedens viruses, some of which encode multi-haem cytochromes, and circular ECEs encoding transposon-associated TnpB genes with proximal population-heterogeneous CRISPR arrays. These ECEs exchange genetic information with each other and with Methanoperedens, probably impacting their archaeal host activity and evolution.

20.
Cell Host Microbe ; 32(1): 35-47.e6, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38096814

RESUMO

Bacteriophages are key components of gut microbiomes, yet the phage colonization process in the infant gut remains uncertain. Here, we establish a large phage sequence database and use strain-resolved analyses to investigate DNA phage succession in infants throughout the first 3 years of life. Analysis of 819 fecal metagenomes collected from 28 full-term and 24 preterm infants and their mothers revealed that early-life phageome richness increases over time and reaches adult-like complexity by age 3. Approximately 9% of early phage colonizers, which are mostly maternally transmitted and infect Bacteroides, persist for 3 years and are more prevalent in full-term than in preterm infants. Although rare, phages with stop codon reassignment are more likely to persist than non-recoded phages and generally display an increase in in-frame reassigned stop codons over 3 years. Overall, maternal seeding, stop codon reassignment, host CRISPR-Cas locus prevalence, and diverse phage populations contribute to stable viral colonization.


Assuntos
Bacteriófagos , Microbioma Gastrointestinal , Lactente , Feminino , Adulto , Humanos , Recém-Nascido , Pré-Escolar , Bacteriófagos/genética , Códon de Terminação , Recém-Nascido Prematuro , Microbioma Gastrointestinal/genética , DNA
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