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1.
Sheng Wu Gong Cheng Xue Bao ; 37(9): 3020-3030, 2021 Sep 25.
Artigo em Chinês | MEDLINE | ID: mdl-34622614

RESUMO

P1B-ATPases are a group of proteins that can transport heavy metal ions across membranes by hydrolyzing ATP and they are a subclass of the P-type ATPase family. It was found that P1B-ATPases are mainly responsible for the active transport of heavy metal ions in plants and play an important role in the regulation of heavy metal homeostasis in plants. In this paper, we dissusses the mechanism of P1B-ATPases from the structure and classification of P1B-ATPases, and review the current research progress in the function of P1B-ATPases, in order to provide reference for future research and application of P1B-ATPases in improving crop quality and ecological environment management.


Assuntos
Adenosina Trifosfatases , Metais Pesados , Plantas/enzimologia , Adenosina Trifosfatases/metabolismo , Transporte Biológico
2.
Phys Rev Lett ; 127(13): 138101, 2021 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-34623846

RESUMO

The spatiotemporal organization of bacterial cells is crucial for the active segregation of replicating chromosomes. In several species, including Caulobacter crescentus, the ATPase ParA binds to DNA and forms a gradient along the long cell axis. The ParB partition complex on the newly replicated chromosome translocates up this ParA gradient, thereby contributing to chromosome segregation. A DNA-relay mechanism-deriving from the elasticity of the fluctuating chromosome-has been proposed as the driving force for this cargo translocation, but a mechanistic theoretical description remains elusive. Here, we propose a minimal model to describe force generation by the DNA-relay mechanism over a broad range of operational conditions. Conceptually, we identify four distinct force-generation regimes characterized by their dependence on chromosome fluctuations. These relay force regimes arise from an interplay of the imposed ParA gradient, chromosome fluctuations, and an emergent friction force due to chromosome-cargo interactions.


Assuntos
DNA Bacteriano/metabolismo , Modelos Biológicos , Adenosina Trifosfatases/genética , Adenosina Trifosfatases/metabolismo , Transporte Biológico , Caulobacter crescentus/genética , Caulobacter crescentus/metabolismo , Segregação de Cromossomos , Cromossomos Bacterianos , DNA Primase/química , DNA Primase/genética , DNA Primase/metabolismo , DNA Bacteriano/química , DNA Bacteriano/genética
3.
BMC Gastroenterol ; 21(1): 339, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34470610

RESUMO

AIM: To discover the novel ATP7B mutations in 103 southern Chinese patients with Wilson disease (WD), and to determine the spectrum and frequency of mutations in the ATP7B gene and genotype-phenotype correlation in a large-scale sample of Chinese WD patients. METHODS: One hundred three WD patients from 101 unrelated families in southern China were enrolled in this study. Genomic DNA was extracted from the peripheral blood. Direct sequencing of all 21 exons within ATP7B was performed. Subsequently, an extensive study of the overall spectrum and frequency of ATP7B mutations and genotype-phenotype correlation was performed in all Chinese patients eligible from the literature, combined with the current southern group. RESULTS: In 103 patients with WD, we identified 48 different mutations (42 missense mutations, 4 nonsense mutations and 2 frameshifts). Of these, 3 mutations had not been previously reported: c.1510_1511insA, c.2233C>A (p.Leu745Met) and c.3824T>C (p.Leu1275Ser). The c.2333G>T (p.Arg778 Leu) at exon 8, was the most common mutation with an allelic frequency of 18.8%, followed by c.2975C>T (p.Pro992Leu) at exon 13, with an allelic frequency of 13.4%. In the comprehensive study, 233 distinct mutations were identified, including 154 missense mutations, 23 nonsense mutations and 56 frameshifts. Eighty-five variants were identified as novel mutations. The c.2333G>T (p.Arg778 Leu) and c.2975C>T (p.Pro992Leu) were the most common mutations, with allelic frequencies of 28.6% and 13.0%, respectively. Exons 8, 12, 13, 16 and 18 were recognised as hotspot exons. Phenotype-genotype correlation analysis suggested that c.2333G>T (p.Arg778 Leu) was significantly associated with lower levels of serum ceruloplasmin (P = 0.034). c.2975C>T (p.Pro992Leu) was correlated with earlier age of disease onset (P = 0.002). Additionally, we found that the c.3809A>G (p.Asn1270Ser) mutation significantly indicated younger onset age (P = 0.012), and the c.3884C>T (p.Ala1295Val) mutation at exon 18 was significantly associated with hepatic presentation (P = 0.048). Moreover, the patients with mixed presentation displayed the initial WD features at an older onset age than the groups with either liver disease or neurological presentation (P = 0.039, P = 0.015, respectively). No significant difference was observed in the presence of KF rings among the three groups with different clinical manifestations. CONCLUSION: In this study, we identified three novel mutations in 103 WD patients from the southern part of China, which could enrich the previously established mutational spectrum of the ATP7B gene. Moreover, we tapped into a large-scale study of a Chinese WD cohort to characterise the overall phenotypic and genotypic spectra and assess the association between genotype and phenotype, which enhances the current knowledge about the population genetics of WD in China.


Assuntos
Proteínas de Transporte de Cátions , ATPases Transportadoras de Cobre , Degeneração Hepatolenticular , Adenosina Trifosfatases/genética , Adenosina Trifosfatases/metabolismo , Proteínas de Transporte de Cátions/genética , China , ATPases Transportadoras de Cobre/genética , Análise Mutacional de DNA , Estudos de Associação Genética , Genótipo , Degeneração Hepatolenticular/genética , Humanos , Mutação
4.
Neurosurg Focus ; 51(3): E5, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34469865

RESUMO

OBJECTIVE: Moyamoya disease (MMD) is an intracranial steno-occlusive pathology characterized by progressive narrowing of proximal large vessels, including the terminal internal carotid arteries (ICAs), middle cerebral arteries, or anterior cerebral arteries. Named for the "puff of smoke" appearance of the anomalous vascularization visualized on cerebral angiography, MMD lacks a well-defined etiology, although significant insights have been made, including the identification of a susceptibility gene, RNF213, in humans with the disease. A limitation to advancing the understanding and treatment of MMD has been the lack of experimental animal models that authentically reflect the clinical pathogenesis. In an effort to analyze characteristics of currently available models and identify strategies for future model generation, the authors performed a scoping review of experimental animal models that have been used to study MMD. METHODS: A systematic search of PubMed, Web of Science, and Scopus was performed to identify articles describing animal models used to study MMD. Additional articles were identified via citation searching. Study selection and data extraction were performed by two independent reviewers based on defined inclusion and exclusion criteria. RESULTS: A total of 44 articles were included for full-text review. The methods used to generate these animal models were broadly classified as surgical (n = 25, 56.8%), immunological (n = 7, 15.9%), genetic (n = 6, 13.6%), or a combination (n = 6, 13.6%). Surgical models typically involved permanent ligation of one or both of the common carotid arteries or ICAs to produce chronic cerebral hypoperfusion. Genetic models utilized known MMD or cerebrovascular disease-related genes, such as RNF213 or ACTA2, to induce heritable cerebral vasculopathy. Finally, immunological models attempted to induce vasculitis-type pathology by recapitulating the inflammatory milieu thought to underlie MMD. CONCLUSIONS: Models generated for MMD have involved three general approaches: surgical, immunological, and genetic. Although each reflects a key aspect of MMD pathogenesis, the failure of any individual model to recapitulate the development, progression, and consequences of the disease underscores the importance of future work in developing a multietiology model.


Assuntos
Doença de Moyamoya , Adenosina Trifosfatases/genética , Animais , Predisposição Genética para Doença , Humanos , Modelos Animais , Doença de Moyamoya/genética , Doença de Moyamoya/cirurgia , Ubiquitina-Proteína Ligases/genética
5.
Neurosurg Focus ; 51(3): E2, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34469872

RESUMO

OBJECTIVE: Quasi-moyamoya disease (QMMD) is moyamoya disease (MMD) associated with additional underlying diseases. Although the ring finger protein 213 (RNF213) c.14576G>A mutation is highly correlated with MMD in the Asian population, its relationship to QMMD is unclear. Therefore, in this study the authors sought to investigate the RNF213 c.14576G>A mutation in the genetic diagnosis and classification of QMMD. METHODS: This case-control study was conducted among four core hospitals. A screening system for the RNF213 c.14576G>A mutation based on high-resolution melting curve analysis was designed. The prevalence of RNF213 c.14576G>A was investigated in 76 patients with MMD and 10 patients with QMMD. RESULTS: There were no significant differences in age, sex, family history, and mode of onset between the two groups. Underlying diseases presenting in patients with QMMD were hyperthyroidism (n = 6), neurofibromatosis type 1 (n = 2), Sjögren's syndrome (n = 1), and meningitis (n =1). The RNF213 c.14576G>A mutation was found in 64 patients (84.2%) with MMD and 8 patients (80%) with QMMD; no significant difference in mutation frequency was observed between cohorts. CONCLUSIONS: There are two forms of QMMD, one in which the vascular abnormality is associated with an underlying disease, and the other in which MMD is coincidentally complicated by an unrelated underlying disease. It has been suggested that the presence or absence of the RNF213 c.14576G>A mutation may be useful in distinguishing between these disease types.


Assuntos
Doença de Moyamoya , Adenosina Trifosfatases/genética , Estudos de Casos e Controles , Predisposição Genética para Doença/genética , Humanos , Doença de Moyamoya/epidemiologia , Doença de Moyamoya/genética , Ubiquitina-Proteína Ligases/genética
6.
Nat Commun ; 12(1): 5224, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34471130

RESUMO

The replication of chromosomes during S phase is critical for cellular and organismal function. Replicative stress can result in genome instability, which is a major driver of cancer. Yet how chromatin is made accessible during eukaryotic DNA synthesis is poorly understood. Here, we report the characterization of a chromatin remodeling enzyme-Yta7-entirely distinct from classical SNF2-ATPase family remodelers. Yta7 is a AAA+ -ATPase that assembles into ~1 MDa hexameric complexes capable of segregating histones from DNA. The Yta7 chromatin segregase promotes chromosome replication both in vivo and in vitro. Biochemical reconstitution experiments using purified proteins revealed that the enzymatic activity of Yta7 is regulated by S phase-forms of Cyclin-Dependent Kinase (S-CDK). S-CDK phosphorylation stimulates ATP hydrolysis by Yta7, promoting nucleosome disassembly and chromatin replication. Our results present a mechanism for how cells orchestrate chromatin dynamics in co-ordination with the cell cycle machinery to promote genome duplication during S phase.


Assuntos
Cromatina/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Quinases Ciclina-Dependentes/metabolismo , Replicação do DNA/fisiologia , Proteínas de Saccharomyces cerevisiae/metabolismo , Adenosina Trifosfatases/metabolismo , Pontos de Checagem do Ciclo Celular , Montagem e Desmontagem da Cromatina , Proteínas Cromossômicas não Histona/genética , DNA/metabolismo , Histonas/metabolismo , Humanos , Fosforilação , Fase S , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Fatores de Transcrição
7.
Proc Natl Acad Sci U S A ; 118(39)2021 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-34548395

RESUMO

Extracellular adenosine triphosphate (ATP) released by mucosal immune cells and by microbiota in the intestinal lumen elicits diverse immune responses that mediate the intestinal homeostasis via P2 purinergic receptors, while overactivation of ATP signaling leads to mucosal immune system disruption, which leads to pathogenesis of intestinal inflammation. In the small intestine, hydrolysis of luminal ATP by ectonucleoside triphosphate diphosphohydrolase (E-NTPD)7 in epithelial cells is essential for control of the number of T helper 17 (Th17) cells. However, the molecular mechanism by which microbiota-derived ATP in the colon is regulated remains poorly understood. Here, we show that E-NTPD8 is highly expressed in large-intestinal epithelial cells and hydrolyzes microbiota-derived luminal ATP. Compared with wild-type mice, Entpd8 -/- mice develop more severe dextran sodium sulfate-induced colitis, which can be ameliorated by either the depletion of neutrophils and monocytes by injecting with anti-Gr-1 antibody or the introduction of P2rx4 deficiency into hematopoietic cells. An increased level of luminal ATP in the colon of Entpd8 -/- mice promotes glycolysis in neutrophils through P2x4 receptor-dependent Ca2+ influx, which is linked to prolonged survival and elevated reactive oxygen species production in these cells. Thus, E-NTPD8 limits intestinal inflammation by controlling metabolic alteration toward glycolysis via the P2X4 receptor in myeloid cells.


Assuntos
Adenosina Trifosfatases/fisiologia , Trifosfato de Adenosina/metabolismo , Colite/prevenção & controle , Glicólise , Células Mieloides/metabolismo , Receptores Purinérgicos P2X4/metabolismo , Células Th17/imunologia , Animais , Células Cultivadas , Colite/etiologia , Colite/metabolismo , Colite/patologia , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células Mieloides/imunologia , Células Mieloides/patologia , Receptores Purinérgicos P2X4/genética , Transdução de Sinais
8.
Phytochemistry ; 191: 112911, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34418773

RESUMO

The pleiotropic effects of zinc deficiency on ion homeostasis have already been described in several plants. Tobacco (Nicotiana tabacum) heavy metal ATPases HMA4.1 and HMA4.2 are involved in zinc and cadmium root-to-shoot translocation. In previous research, we have shown that N. tabacum HMA4 RNAi plants and HMA4 double-nonsense mutants exhibit strongly reduced zinc and cadmium levels in leaves as well as stunted growth. In this study, the ionome and transcriptome of these lines were investigated to better characterize the effect of reduced zinc levels and to understand the impaired growth phenotype. We found that, under standard greenhouse fertilization rates, these lines accumulated up to 4- to 6-fold more phosphorus, iron, manganese, and copper than their respective controls. Under field conditions, HMA4 double-mutant plants also exhibited similar accumulation phenotypes, albeit to a lower extent. In both HMA4 RNAi plants and HMA4 mutants, transcription analysis showed a local zinc-deficiency response in leaves as well as an FIT1-mediated iron-deficiency response in roots, likely contributing to iron and manganese uptake at the root level. A phosphate-starvation response involving HHO2 was also observed in HMA4-impaired plant leaves. The high level of phosphorus observed in HMA4-impaired plants is correlated with leaf swelling and necrosis. The upregulation of aquaporin genes is in line with cellular water influx and the observed leaf swelling phenotype. These results highlight the involvement of HMA4 in zinc homeostasis and related regulatory processes that balance the micro- and macroelements in above-ground organs.


Assuntos
Cádmio , Tabaco , Adenosina Trifosfatases/genética , Adenosina Trifosfatases/metabolismo , Cádmio/metabolismo , Regulação da Expressão Gênica de Plantas , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Tabaco/metabolismo , Zinco/metabolismo
9.
Viruses ; 13(8)2021 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-34452405

RESUMO

Transcriptomics, proteomics and pathogen-host interactomics data are being explored for the in silico-informed selection of drugs, prior to their functional evaluation. The effectiveness of this kind of strategy has been put to the test in the current COVID-19 pandemic, and it has been paying off, leading to a few drugs being rapidly repurposed as treatment against SARS-CoV-2 infection. Several neglected tropical diseases, for which treatment remains unavailable, would benefit from informed in silico investigations of drugs, as performed in this work for Dengue fever disease. We analyzed transcriptomic data in the key tissues of liver, spleen and blood profiles and verified that despite transcriptomic differences due to tissue specialization, the common mechanisms of action, "Adrenergic receptor antagonist", "ATPase inhibitor", "NF-kB pathway inhibitor" and "Serotonin receptor antagonist", were identified as druggable (e.g., oxprenolol, digoxin, auranofin and palonosetron, respectively) to oppose the effects of severe Dengue infection in these tissues. These are good candidates for future functional evaluation and clinical trials.


Assuntos
Antivirais/uso terapêutico , Dengue/tratamento farmacológico , Transcriptoma , Adenosina Trifosfatases/antagonistas & inibidores , Antagonistas Adrenérgicos/farmacologia , Antagonistas Adrenérgicos/uso terapêutico , Antivirais/farmacologia , Encéfalo/metabolismo , Simulação por Computador , Dengue/sangue , Dengue/genética , Dengue/metabolismo , Descoberta de Drogas , Avaliação Pré-Clínica de Medicamentos , Reposicionamento de Medicamentos , Humanos , Fígado/metabolismo , Redes e Vias Metabólicas/efeitos dos fármacos , NF-kappa B/metabolismo , Antagonistas da Serotonina/farmacologia , Antagonistas da Serotonina/uso terapêutico , Dengue Grave/sangue , Dengue Grave/tratamento farmacológico , Dengue Grave/genética , Dengue Grave/metabolismo , Baço/metabolismo
10.
Structure ; 29(8): 781-782, 2021 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-34358463

RESUMO

The bacterial Sec translocase transports unfolded proteins across membranes. In this issue of Structure, Krishnamurthy et al. (2021) report a nexus of conformational dynamics in the translocase motor protein, SecA. Their findings shed light on the Sec activation mechanism and suggest a general role for multi-level dynamics in protein functions.


Assuntos
Proteínas de Bactérias , Proteínas de Membrana Transportadoras , Adenosina Trifosfatases/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Transporte Proteico , Canais de Translocação SEC/genética , Proteínas SecA
11.
Nat Commun ; 12(1): 4750, 2021 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-34362907

RESUMO

Budding yeast Dpb4 (POLE3/CHRAC17 in mammals) is a highly conserved histone fold protein that is shared by two protein complexes: the chromatin remodeler ISW2/hCHRAC and the DNA polymerase ε (Pol ε) holoenzyme. In Saccharomyces cerevisiae, Dpb4 forms histone-like dimers with Dls1 in the ISW2 complex and with Dpb3 in the Pol ε complex. Here, we show that Dpb4 plays two functions in sensing and processing DNA double-strand breaks (DSBs). Dpb4 promotes histone removal and DSB resection by interacting with Dls1 to facilitate the association of the Isw2 ATPase to DSBs. Furthermore, it promotes checkpoint activation by interacting with Dpb3 to facilitate the association of the checkpoint protein Rad9 to DSBs. Persistence of both Isw2 and Rad9 at DSBs is enhanced by the A62S mutation that is located in the Dpb4 histone fold domain and increases Dpb4 association at DSBs. Thus, Dpb4 exerts two distinct functions at DSBs depending on its interactors.


Assuntos
Quebras de DNA de Cadeia Dupla , DNA Polimerase II/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Adenosina Trifosfatases/metabolismo , Montagem e Desmontagem da Cromatina , DNA/metabolismo , Dano ao DNA , Reparo do DNA , Histonas/metabolismo , Mutação , Fatores de Transcrição
12.
Nat Commun ; 12(1): 5166, 2021 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-34453062

RESUMO

The efficient segregation of replicated genetic material is an essential step for cell division. Bacterial cells use several evolutionarily-distinct genome segregation systems, the most common of which is the type I Par system. It consists of an adapter protein, ParB, that binds to the DNA cargo via interaction with the parS DNA sequence; and an ATPase, ParA, that binds nonspecific DNA and mediates cargo transport. However, the molecular details of how this system functions are not well understood. Here, we report the cryo-EM structure of the Vibrio cholerae ParA2 filament bound to DNA, as well as the crystal structures of this protein in various nucleotide states. These structures show that ParA forms a left-handed filament on DNA, stabilized by nucleotide binding, and that ParA undergoes profound structural rearrangements upon DNA binding and filament assembly. Collectively, our data suggest the structural basis for ParA's cooperative binding to DNA and the formation of high ParA density regions on the nucleoid.


Assuntos
Adenosina Trifosfatases/química , Adenosina Trifosfatases/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , DNA Bacteriano/química , DNA Bacteriano/metabolismo , Vibrio cholerae/metabolismo , Adenosina Trifosfatases/genética , Proteínas de Bactérias/genética , Segregação de Cromossomos , Microscopia Crioeletrônica , Cristalografia por Raios X , DNA Bacteriano/genética , Conformação de Ácido Nucleico , Conformação Proteica , Vibrio cholerae/química , Vibrio cholerae/enzimologia , Vibrio cholerae/genética
13.
Nat Commun ; 12(1): 5098, 2021 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-34429416

RESUMO

KdpFABC, a high-affinity K+ pump, combines the ion channel KdpA and the P-type ATPase KdpB to secure survival at K+ limitation. Here, we apply a combination of cryo-EM, biochemical assays, and MD simulations to illuminate the mechanisms underlying transport and the coupling to ATP hydrolysis. We show that ions are transported via an intersubunit tunnel through KdpA and KdpB. At the subunit interface, the tunnel is constricted by a phenylalanine, which, by polarized cation-π stacking, controls K+ entry into the canonical substrate binding site (CBS) of KdpB. Within the CBS, ATPase coupling is mediated by the charge distribution between an aspartate and a lysine. Interestingly, individual elements of the ion translocation mechanism of KdpFABC identified here are conserved among a wide variety of P-type ATPases from different families. This leads us to the hypothesis that KdpB might represent an early descendant of a common ancestor of cation pumps.


Assuntos
Adenosina Trifosfatases/química , Adenosina Trifosfatases/metabolismo , Proteínas de Transporte de Cátions/química , Proteínas de Transporte de Cátions/metabolismo , Transporte de Íons/fisiologia , Ácido Aspártico/metabolismo , Sítios de Ligação , Proteínas de Transporte de Cátions/genética , Microscopia Crioeletrônica , Escherichia coli/metabolismo , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Lisina/metabolismo , Simulação de Dinâmica Molecular , Mutação , Fenilalanina , Potássio/metabolismo , Subunidades Proteicas , ATPase Trocadora de Sódio-Potássio
14.
Antimicrob Agents Chemother ; 65(10): e0077121, 2021 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-34339273

RESUMO

Among novel compounds under recent investigation as potential new antimalarial drugs are three independently developed inhibitors of the Plasmodium falciparum P-type ATPase (PfATP4): KAE609 (cipargamin), PA92, and SJ733. We assessed ex vivo susceptibilities to these compounds of 374 fresh P. falciparum isolates collected in Tororo and Busia districts, Uganda, from 2016 to 2019. Median IC50s were 65 nM for SJ733, 9.1 nM for PA92, and 0.5 nM for KAE609. Sequencing of pfatp4 for 218 of these isolates demonstrated many nonsynonymous single nucleotide polymorphisms; the most frequent mutations were G1128R (69% of isolates mixed or mutant), Q1081K/R (68%), G223S (25%), N1045K (16%), and D1116G/N/Y (16%). The G223S mutation was associated with decreased susceptibility to SJ733, PA92, and KAE609. The D1116G/N/Y mutations were associated with decreased susceptibility to SJ733, and the presence of mutations at both codons 223 and 1116 was associated with decreased susceptibility to PA92 and SJ733. In all of these cases, absolute differences in susceptibilities of wild-type (WT) and mutant parasites were modest. Analysis of clones separated from mixed field isolates consistently identified mutant clones as less susceptible than WT. Analysis of isolates from other sites demonstrated the presence of the G223S and D1116G/N/Y mutations across Uganda. Our results indicate that malaria parasites circulating in Uganda have a number of polymorphisms in PfATP4 and that modestly decreased susceptibility to PfATP4 inhibitors is associated with some mutations now present in Ugandan parasites.


Assuntos
Antimaláricos , Malária Falciparum , Adenosina Trifosfatases , Antimaláricos/farmacologia , Antimaláricos/uso terapêutico , Resistência a Medicamentos/genética , Genótipo , Humanos , Malária Falciparum/tratamento farmacológico , Plasmodium falciparum/genética , Proteínas de Protozoários/genética , Proteínas de Protozoários/uso terapêutico , Uganda
15.
Science ; 373(6552): 306-315, 2021 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-34437148

RESUMO

Mammalian SWI/SNF (mSWI/SNF) adenosine triphosphate-dependent chromatin remodelers modulate genomic architecture and gene expression and are frequently mutated in disease. However, the specific chromatin features that govern their nucleosome binding and remodeling activities remain unknown. We subjected endogenously purified mSWI/SNF complexes and their constituent assembly modules to a diverse library of DNA-barcoded mononucleosomes, performing more than 25,000 binding and remodeling measurements. Here, we define histone modification-, variant-, and mutation-specific effects, alone and in combination, on mSWI/SNF activities and chromatin interactions. Further, we identify the combinatorial contributions of complex module components, reader domains, and nucleosome engagement properties to the localization of complexes to selectively permissive chromatin states. These findings uncover principles that shape the genomic binding and activity of a major chromatin remodeler complex family.


Assuntos
Montagem e Desmontagem da Cromatina , Cromatina/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Nucleossomos/metabolismo , Fatores de Transcrição/metabolismo , Adenosina Trifosfatases/química , Adenosina Trifosfatases/metabolismo , Trifosfato de Adenosina/metabolismo , Proteínas Cromossômicas não Histona/química , Código das Histonas , Histonas/química , Histonas/metabolismo , Humanos , Modelos Moleculares , Complexos Multiproteicos/metabolismo , Mutação , Nucleossomos/química , Ligação Proteica , Domínios Proteicos , Subunidades Proteicas/química , Subunidades Proteicas/metabolismo , Fatores de Transcrição/química
16.
Chem Biol Interact ; 347: 109582, 2021 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-34302802

RESUMO

Different aspects of reproductive functions are regulated by mitochondrial-controlled events. This study investigated the effect of plumbagin (PL) on testicular mitochondria with a view to unravelling the mechanism of the antifertility potential of plumbagin in testis of healthy rats. Thirty-two male Wistar strain albino rats were randomly allocated into four groups of eight animals each. The control or healthy group received orally 0.1 % DMSO while animals in the remaining three groups received 2.5 mg PL/kg bdwt, 5.0 mg PL/kg bdwt and 10 mg PL/kg bdwt, respectively, for 14 days. In study two, twenty-four male Wistar rats were randomly divided into three (3) groups and were orally administered 0.1% DMSO (control), 30 and 100 mg/kg PL, respectively once daily for 72 h. Rat testis mitochondria were isolated using differential centrifugation. The mitochondrial Permeability Transition (mPT) pore, mitochondrial ATPase (mATPase) activity and mitochondrial lipid peroxidation were assessed spectrophotometrically. Expression of apoptotic proteins (p53, Bax, Bcl-2) and the release of cytochrome c were determined by immunochemical technique. Reproductive receptors (FSH, PR), the expression of aromatase, Testis Specific Kinase-1 {TESK-1} were quantified by RT-PCR. The various doses of plumbagin (2.5, 5.0 and 10 mg/kg bdwt) induced opening of the testicular mPT pore by 2, 5 and 8 folds, respectively, after 14 days of oral administration. These doses of plumbagin also caused enhancement of mATPase activity, elevated generation of mLPO as well as increases in the concentrations of caspases 9 and 3. Sperm analysis revealed that these doses of PL also caused significant decreases in sperm count and motility and increased sperm abnormalities compared to control. Interestingly, these effects were accompanied by dose-dependent expressions of the Bak, p53 and cytochrome c release. Conversely, the abundance of anti-apoptotic Bcl-2 protein decreased relative to control. The levels of transcripts of FSH and progesterone receptors as well as TESK-1 and aromatase decreased significantly relative to control. Furthermore, PL strongly inhibited p53-MDM2 compared to control. Altogether, these findings show that plumbagin damages testicular cells through the activation of mitochondrial pathway involving the p53 protein network.


Assuntos
Morte Celular/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Naftoquinonas/farmacologia , Testículo/efeitos dos fármacos , Adenosina Trifosfatases/metabolismo , Animais , Apoptose/efeitos dos fármacos , Caspase 9/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Mitocôndrias/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Ratos , Ratos Wistar , Transdução de Sinais/efeitos dos fármacos , Espermatozoides/efeitos dos fármacos , Espermatozoides/metabolismo , Testículo/metabolismo , Proteína Supressora de Tumor p53/metabolismo
17.
Biomolecules ; 11(7)2021 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-34206878

RESUMO

Helicase proteins are known to use the energy of ATP to unwind nucleic acids and to remodel protein-nucleic acid complexes. They are involved in almost every aspect of DNA and RNA metabolisms and participate in numerous repair mechanisms that maintain cellular integrity. The archaeal Lhr-type proteins are SF2 helicases that are mostly uncharacterized. They have been proposed to be DNA helicases that act in DNA recombination and repair processes in Sulfolobales and Methanothermobacter. In Thermococcales, a protein annotated as an Lhr2 protein was found in the network of proteins involved in RNA metabolism. To investigate this, we performed in-depth phylogenomic analyses to report the classification and taxonomic distribution of Lhr-type proteins in Archaea, and to better understand their relationship with bacterial Lhr. Furthermore, with the goal of envisioning the role(s) of aLhr2 in Thermococcales cells, we deciphered the enzymatic activities of aLhr2 from Thermococcus barophilus (Tbar). We showed that Tbar-aLhr2 is a DNA/RNA helicase with a significant annealing activity that is involved in processes dependent on DNA and RNA transactions.


Assuntos
DNA Helicases/genética , RNA Helicases/genética , Thermococcales/enzimologia , Adenosina Trifosfatases/genética , Proteínas Arqueais/química , DNA/química , DNA Helicases/isolamento & purificação , DNA Helicases/metabolismo , Filogenia , RNA/química , RNA Helicases/isolamento & purificação , RNA Helicases/metabolismo , Homologia de Sequência de Aminoácidos , Thermococcales/genética , Thermococcales/metabolismo
18.
Biomolecules ; 11(7)2021 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-34209820

RESUMO

Evidence indicates that patients with Alzheimer's dementia (AD) show signs of copper (Cu) dyshomeostasis. This study aimed at evaluating the potential of Cu dysregulation as an AD susceptibility factor. We performed a meta-analysis of 56 studies investigating Cu biomarkers in brain specimens (pooled total of 182 AD and 166 healthy controls, HC) and in serum/plasma (pooled total of 2929 AD and 3547 HC). We also completed a replication study of serum Cu biomarkers in 97 AD patients and 70 HC screened for rs732774 and rs1061472 ATP7B, the gene encoding for the Cu transporter ATPase7B. Our meta-analysis showed decreased Cu in AD brain specimens, increased Cu and nonbound ceruloplasmin (Non-Cp) Cu in serum/plasma samples, and unchanged ceruloplasmin. Serum/plasma Cu excess was associated with a three to fourfold increase in the risk of having AD. Our replication study confirmed meta-analysis results and showed that carriers of the ATP7B AG haplotype were significantly more frequent in the AD group. Overall, our study shows that AD patients fail to maintain a Cu metabolic balance and reveals the presence of a percentage of AD patients carrying ATP7B AG haplotype and presenting Non-Cp Cu excess, which suggest that a subset of AD subjects is prone to Cu imbalance. This AD subtype can be the target of precision medicine-based strategies tackling Cu dysregulation.


Assuntos
Doença de Alzheimer/metabolismo , ATPases Transportadoras de Cobre/genética , Cobre/metabolismo , Adenosina Trifosfatases/genética , Doença de Alzheimer/genética , Biomarcadores/análise , Encéfalo/metabolismo , Proteínas de Transporte de Cátions/genética , Ceruloplasmina/análise , Cobre/sangue , Suscetibilidade a Doenças , Haplótipos/genética , Homeostase , Humanos , Polimorfismo de Nucleotídeo Único/genética , Fatores de Risco
19.
Nucleic Acids Res ; 49(13): 7618-7627, 2021 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-34197619

RESUMO

Transcription induced CAG repeat instability is associated with fatal neurological disorders. Genetic approaches found transcription-coupled nucleotide excision repair (TC-NER) factor CSB protein and TFIIS play critical roles in modulating the repeat stability. Here, we took advantage of an in vitro reconstituted yeast transcription system to investigate the underlying mechanism of RNA polymerase II (Pol II) transcriptional pausing/stalling by CAG slip-out structures and the functions of TFIIS and Rad26, the yeast ortholog of CSB, in modulating transcriptional arrest. We identified length-dependent and strand-specific mechanisms that account for CAG slip-out induced transcriptional arrest. We found substantial R-loop formation for the distal transcriptional pausing induced by template strand (TS) slip-out, but not non-template strand (NTS) slip-out. In contrast, Pol II backtracking was observed at the proximal transcriptional pausing sites induced by both NTS and TS slip-out blockage. Strikingly, we revealed that Rad26 and TFIIS can stimulate bypass of NTS CAG slip-out, but not TS slip-out induced distal pausing. Our biochemical results provide new insights into understanding the mechanism of CAG slip-out induced transcriptional pausing and functions of transcription factors in modulating transcription-coupled CAG repeat instability, which may pave the way for developing potential strategies for the treatment of repeat sequence associated human diseases.


Assuntos
Adenosina Trifosfatases/metabolismo , RNA Polimerase II/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Elongação da Transcrição Genética , Fatores de Elongação da Transcrição/metabolismo , Repetições de Trinucleotídeos , Estruturas R-Loop
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