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1.
Front Pharmacol ; 14: 1233617, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37886128

RESUMO

The past decade has seen the increasing influence and relevance of real-world data (RWD) and real-world evidence (RWE) in healthcare decision making. The value added by RWD/RWE has prompted the pharmaceutical industry to develop high performing systems and practices to harness the power of evidence generated at the global level. However, this worldwide transformation provides outstanding opportunities to support capability building within local affiliates and to impact key country-level stakeholders through resulting evidence. Therefore, we present an Evidence Blueprint Initiative, which links the global and local ("glocal") skills, and furthermore addresses the opportunities and gaps in evidence generation capabilities at the local level. Cross-functional experts were recruited at the local, regional, and global level to define best practices. A framework was developed to characterize the foundational expertise needed and to assess markets' existing capabilities. Subsequently, targeted roadmaps were developed and implemented to build capabilities in specific areas within each affiliate. The impact from the Blueprint is encouraging, resulting in improved local evidence plans, established evidence teams, enhanced RWD use and strategic implementation of patient centric science in local affiliates. The success of the Blueprint resides in empowering affiliates to realise their local evidence generation ambitions and to match them to their local context. It strengthens and expands the ties between various parts of the organisation and the external environment while building fit-for-future evidence capabilities from local affiliates.

2.
Water Res ; 235: 119824, 2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-36913811

RESUMO

Aluminum salts are widely used to immobilize phosphorus (P) in lakes suffering from internal loading. However, longevity of treatments varies among lakes; some lakes eutrophy faster than others. We conducted biogeochemical investigations of sediments of a closed artificial Lake Barleber, Germany that was successfully remediated with aluminum sulfate in 1986. The lake became mesotrophic for almost 30 years; a rather rapid re-eutrophication took place in 2016 leading to massive cyanobacterial blooms. We quantified internal loading from sediment and analyzed two environmental factors that might have contributed to the sudden shift in trophic state. Increase in lake P concentration started in 2016, reaching 0.3 mg L-1, and remained elevated into the spring of 2018. Reducible P fraction in the sediment was 37 - 58% of total P, indicating a high potential for mobilization of benthic P during anoxia. Estimated P release from sediments for 2017 was approximately 600 kg for the whole lake. This is consistent with sediment incubation results; higher temperature (20°C) and anoxia contributed to release of P (27.9 ± 7.1 mg m-2 d-1, 0.94 ± 0.23 mmol m-2 d-1) to the lake, triggering re-eutrophication. Loss of aluminum P adsorption capacity together with anoxia and high water temperatures (organic matter mineralization) are major drivers of re-eutrophication. Accordingly, treated lakes at some time require a repeated aluminum treatment for sustaining acceptable water quality and we recommend regular sediment monitoring in treated lakes. This is crucial given the effects of climate warming on duration of stratification in lakes which may result in the need for treatment of many lakes.


Assuntos
Alumínio , Lagos , Humanos , Fósforo/análise , Sedimentos Geológicos , Compostos de Alúmen , Eutrofização , Hipóxia , Monitoramento Ambiental
3.
Sci Total Environ ; 838(Pt 3): 156541, 2022 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-35679920

RESUMO

Dissolved oxygen (DO) dynamics of a temperate drinking water reservoir in the Harz Mountains (Germany) were investigated over a time period of 18 months. Via depth profiles in a fortnightly sampling resolution we were able to trace DO and temperature dynamics including the formation and breakdown of a Metalimnetic Oxygen Minimum (MOM) by means of DO concentration, saturation patterns and stable isotope ratios of dissolved oxygen (expressed as δ18ODO). Over the evaluation period, 19.4 % of the samples collected had δ18ODO values compatible with atmospheric equilibration (+24.6 ‰ ± 0.4 ‰). With values smaller and larger than this threshold, the remaining δ18ODO values showed that 40.8 % of our samples were dominated by photosynthesis and 39.8 % by respiration. From December to April the reservoir was mixed and DO consumption by respiration exceeded production via photosynthesis. During stratification period, quantification of respiration/photosynthesis rates (R/P) confirmed the epilimnion as a photosynthetic (i.e. net-autotrophic) environment while the hypolimnion was heterotrophic and dominated by respiration at various degrees. Samples of the MOM zone showed the highest R/P ratios and had among the most positive δ18ODO signals caused by respiration. This study showed that combinations of DO concentrations and their isotope ratios are promising to quantify critical zones of respiration and photosynthesis in aquatic environments.


Assuntos
Água Potável , Oxigênio , Isótopos de Carbono/análise , Isótopos , Oxigênio/análise , Consumo de Oxigênio , Isótopos de Oxigênio/análise , Temperatura
4.
Ther Innov Regul Sci ; 55(4): 889-898, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33914297

RESUMO

In the new era of healthcare digitalization, there is a golden opportunity in the overlap between digital health and Real-World Evidence (RWE). In this commentary, we define RWE and digital health and investigate their intersection. We describe the stages in the RWE value chain critical to the evidence generation process, how these stages change with new digital technologies and the opportunities and challenges that arise from how these stages evolve-including their application for stakeholders such as patients, physicians and regulators. We also discuss the current published guidelines and frameworks regarding digital health. We categorise these publications in terms of their clarity as "Extensive", "Intermediate" or "Basic" and according to whether they encompass all levels of digital health or are more focussed in their guidance. Finally, we provide recommendations to increase synergy between RWE and digital health.

5.
Ther Innov Regul Sci ; 55(1): 90-96, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32632753

RESUMO

This commentary is authored by several industry real-world evidence (RWE) experts, with support from IQVIA, as part of the 'RWE Leadership Forum': a group of Industry Leaders who have come together as non-competitive partners to understand and respond to RWD/E challenges and opportunities with a single expert voice. Here, the forum discusses the value in bridging the industry disconnect between RTCs and RWE, with a view to promoting the use of RWE in the RCT environment. RCT endpoints are explored along several axes including their clinical relevance and their measure of direct patient benefit, and then compared with their real-world counterparts to identify suitable paths, or gaps, for assimilating RWE endpoints into the RCT environment.


Assuntos
Ensaios Clínicos Controlados Aleatórios como Assunto , Humanos
7.
Water Res ; 190: 116681, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33310439

RESUMO

In temperate lakes, it is generally assumed that light rather than temperature constrains phytoplankton growth in winter. Rapid winter warming and increasing observations of winter blooms warrant more investigation of these controls. We investigated the mechanisms regulating a massive winter diatom bloom in a temperate lake. High frequency data and process-based lake modeling demonstrated that phytoplankton growth in winter was dually controlled by light and temperature, rather than by light alone. Water temperature played a further indirect role in initiating the bloom through ice-thaw, which increased light exposure. The bloom was ultimately terminated by silicon limitation and sedimentation. These mechanisms differ from those typically responsible for spring diatom blooms and contributed to the high peak biomass. Our findings show that phytoplankton growth in winter is more sensitive to temperature, and consequently to climate change, than previously assumed. This has implications for nutrient cycling and seasonal succession of lake phytoplankton communities. The present study exemplifies the strength in integrating data analysis with different temporal resolutions and lake modeling. The new lake ecological model serves as an effective tool in analyzing and predicting winter phytoplankton dynamics for temperate lakes.


Assuntos
Diatomáceas , Lagos , Biomassa , Eutrofização , Fitoplâncton , Estações do Ano
8.
J Comp Eff Res ; 9(3): 155-159, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31964167

RESUMO

This White Paper is authored by 11 industry real-world evidence (RWE) experts, with support from IQVIA, as part of the 'RWE Leadership Forum': a group of industry leaders who come together as noncompetitive partners to understand and respond to internal or external RWD/E challenges and opportunities with a single expert voice. Herein we aim to clarify the rules of engagement between pharma and healthcare in order to establish trust-based partnerships, which will unlock unique value for society, including the medical community and the ultimate beneficiary, the patient.


Assuntos
Atenção à Saúde , Indústria Farmacêutica , Confiança , Humanos , Parcerias Público-Privadas
9.
Physiol Genomics ; 42(3): 397-405, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20460602

RESUMO

Mechanical unloading by ventricular assist devices (VAD) leads to significant gene expression changes often summarized as reverse remodeling. However, little is known on individual transcriptome changes during VAD support and its relationship to nonfailing hearts (NF). In addition no data are available for the transcriptome regulation during nonpulsatile VAD support. Therefore we analyzed the gene expression patterns of 30 paired samples from VAD-supported (including 8 nonpulsatile VADs) and 8 nonfailing control hearts (NF) using the first total human genome array available. Transmural myocardial samples were collected for RNA isolation. RNA was isolated by commercial methods and processed according to chip-manufacturer recommendations. cRNA were hybridized on Affymetrix HG-U133 Plus 2.0 arrays, providing coverage of the whole human genome Array. Data were analyzed using Microarray Analysis Suite 5.0 (Affymetrix) and clustered by Expressionist software (Genedata). We found 352 transcripts were differentially regulated between samples from VAD implantation and NF, whereas 510 were significantly regulated between VAD transplantation and NF (paired t-test P < 0.001, fold change >or=1.6). Remarkably, only a minor fraction of 111 transcripts was regulated in heart failure (HF) and during VAD support. Unsupervised hierarchical clustering of paired VAD and NF samples revealed separation of HF and NF samples; however, individual differentiation of VAD implantation and VAD transplantation was not accomplished. Clustering of pulsatile and nonpulsatile VAD did not lead to robust separation of gene expression patterns. During VAD support myocardial gene expression changes do not indicate reversal of the HF phenotype but reveal a distinct HF-related pattern. Transcriptome analysis of pulsatile and nonpulsatile VAD-supported hearts did not provide evidence for a pump mode-specific transcriptome pattern.


Assuntos
Insuficiência Cardíaca/genética , Insuficiência Cardíaca/terapia , Coração Auxiliar , Miocárdio/metabolismo , Adulto , Estudos de Casos e Controles , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/fisiologia , Insuficiência Cardíaca/metabolismo , Insuficiência Cardíaca/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Miocárdio/patologia , Análise de Sequência com Séries de Oligonucleotídeos , Fluxo Pulsátil
10.
Physiol Genomics ; 38(1): 7-15, 2009 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-19293330

RESUMO

Cardiomyocytes derived from pluripotent embryonic stem cells (ESC) have the advantage of providing a source for standardized cell cultures. However, little is known on the regulation of the genome during differentiation of ESC to cardiomyocytes. Here, we characterize the transcriptome of the mouse ESC line CM7/1 during differentiation into beating cardiomyocytes and compare the gene expression profiles with those from primary adult murine cardiomyocytes and left ventricular myocardium. We observe that the cardiac gene expression pattern of fully differentiated CM7/1-ESC is highly similar to adult primary cardiomyocytes and murine myocardium, respectively. This finding is underlined by demonstrating pharmacological effects of catecholamines and endothelin-1 on ESC-derived cardiomyocytes. Furthermore, we monitor the temporal changes in gene expression pattern during ESC differentiation with a special focus on transcription factors involved in cardiomyocyte differentiation. Thus, CM7/1-ESC-derived cardiomyocytes are a promising new tool for functional studies of cardiomyocytes in vitro and for the analysis of the transcription factor network regulating pluripotency and differentiation to cardiomyocytes.


Assuntos
Células-Tronco Embrionárias/metabolismo , Perfilação da Expressão Gênica , Miocárdio/metabolismo , Recombinação Genética , Fatores de Transcrição/genética , Animais , Diferenciação Celular , Linhagem Celular , Células-Tronco Embrionárias/citologia , Camundongos , Reação em Cadeia da Polimerase Via Transcriptase Reversa
11.
J Heart Lung Transplant ; 27(6): 589-96, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18503956

RESUMO

BACKGROUND: In this study we analyzed putative biomarkers for myocardial remodeling in plasma from 55 endstage heart failure patients with the need for mechanical circulatory support (MCS). We compared our data to 40 healthy controls and examined if MCS by either ventricular assist devices or total artificial hearts has an impact on plasma concentrations of remodeling biomarkers. METHODS & RESULTS: Plasma biomarkers were analysed pre and 30 days post implantation of a MCS device using commercially available enzyme linked immunosorbent assays (ELISA). We observed that the plasma concentrations of remodeling biomarkers: tissue inhibitor of metalloproteinase 1 (TIMP1), tenascin C (TNC), galectin 3 (LGALS3), osteopontin (OPN) and of neurohumoral biomarker brain natriuretic peptide (BNP), are significantly elevated in patients with terminal heart failure compared to healthy controls. We did not find elevated plasma concentrations for matrix metalloproteinase 2 (MMP2) and procollagen I C-terminal peptide (PCIP). However, only BNP plasma levels were reduced by MCS, whereas the concentrations of remodeling biomarkers remained elevated or even increased further 30 days after MCS. LGALS3 plasma concentrations at device implantation were significantly higher in patients who did not survive MCS due to multi organ failure (MOF). CONCLUSIONS: Our findings indicate that mechanical unloading in endstage heart failure is not reflected by a rapid reduction of remodeling plasma biomarkers.


Assuntos
Fibrose Endomiocárdica/sangue , Insuficiência Cardíaca/sangue , Insuficiência Cardíaca/fisiopatologia , Coração Auxiliar , Remodelação Ventricular , Adolescente , Adulto , Idoso , Biomarcadores/sangue , Estudos de Casos e Controles , Ensaio de Imunoadsorção Enzimática , Feminino , Galectina 3/sangue , Insuficiência Cardíaca/cirurgia , Humanos , Masculino , Metaloproteinase 1 da Matriz/sangue , Metaloproteinase 2 da Matriz/sangue , Pessoa de Meia-Idade , Peptídeo Natriurético Encefálico/sangue , Osteopontina/sangue , Índice de Gravidade de Doença , Tenascina/sangue
12.
Carcinogenesis ; 28(1): 49-59, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16774935

RESUMO

Insulin-like growth factor (IGF) signaling is a key regulator of breast development and breast cancer. We have analyzed the expression of the IGF signaling cascade in 17 human breast cancer and 4 mammary epithelial cell lines. Five cell lines expressed high levels of IGF1 receptor, insulin (INS)/IGF receptor substrate 1, IGF-binding proteins 2 and 4, as well as the estrogen receptor (ESR), indicating a co-activation of IGF and ESR signaling. Next, we stably overexpressed IGF1 and IGF2 in MCF7 breast cancer cells, which did not affect their epithelial characteristics and the expression and localization of the epithelial marker genes E-cadherin and beta-catenin. Conversely, IGF1 and IGF2 overexpression potently increased cellular proliferation rates and the efficiency of tumor formation in mouse xenograft experiments, whereas the resistance to chemotherapeutic drugs such as taxol was unaltered. Expression profiling of overexpressing cells with whole-genome oligonucleotide microarrays revealed that 21 genes were upregulated >2-fold by both IGF1 and IGF2, 9 by IGF1, and 9 by IGF2. Half of the genes found to be upregulated are involved in transport and biosynthesis of amino acids, including several amino acid transport proteins, argininosuccinate and asparagine synthetases, and methionyl-tRNA synthetase. Upregulation of these genes constitutes a novel mechanism apparently contributing to the stimulatory effects of IGF signaling on the global protein synthesis rate. We conclude that the induction of cell proliferation and tumor formation by long-term IGF stimulation may primarily be due to anabolic effects, in particular increased amino acid production and uptake.


Assuntos
Neoplasias da Mama/metabolismo , Fator de Crescimento Insulin-Like II/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Transdução de Sinais , Transcrição Gênica , Animais , Western Blotting , Proliferação de Células , Sobrevivência Celular , Resistencia a Medicamentos Antineoplásicos , Feminino , Imunofluorescência , Genoma Humano , Humanos , Técnicas Imunoenzimáticas , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Camundongos SCID , Análise de Sequência com Séries de Oligonucleotídeos , Paclitaxel/farmacologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Timidina/metabolismo , Transplante Heterólogo , Células Tumorais Cultivadas
13.
Clin Cancer Res ; 11(23): 8348-57, 2005 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-16322295

RESUMO

PURPOSE: Accurate testing of HER2 is centrally important for breast cancer therapy and prognosis. Immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) are current standard testing methods. As a potential alternative for assessment of HER2, we explored quantitative real-time reverse transcription-PCR (RT-PCR), a fast and inexpensive method yielding quantitative results insensitive to interobserver variability and amenable to standardized scoring. EXPERIMENTAL DESIGN: We assessed HER2 status at the DNA, mRNA, and protein levels with FISH, quantitative RT-PCR, and IHC in 136 tumor samples from 85 breast cancer patients. Expression of GRB7, MLN64, and p21, genes coregulated with HER2, was also quantified with quantitative RT-PCR and correlated with the overall survival (OS) and disease-free survival (DFS) individually and in combination with HER2. RESULTS: Twenty-nine percent and 19% of the patients scored HER2 positive with IHC and quantitative RT-PCR, respectively. In 18 of 19 cases, HER2 statuses in tumors and lymph node metastases were identical. HER2 status significantly correlated with DFS when determined by IHC (P < 0.01), quantitative RT-PCR (P < 0.003), but not with FISH (P = 0.09). The combination of HER2 with MLN64, but not with GRB7 or p21, enhanced the prognostic power for the DFS (P < 0.00005) and OS (P < 0.0008). CONCLUSIONS: Quantitative RT-PCR seems to be clinically as useful in the assessment of HER2 status as IHC and FISH, yielding comparable correlations of HER2 status with the OS and DFS. Thus, quantitative RT-PCR analysis of HER2 or HER2 plus MLN64 is a promising complement or alternative to current methods for HER2 testing, particularly in laboratories lacking FISH or IHC technology.


Assuntos
Neoplasias da Mama/genética , Proteínas de Transporte/genética , Proteína Adaptadora GRB7/genética , Regulação Neoplásica da Expressão Gênica , Proteínas de Membrana/genética , Receptor ErbB-2/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/genética , Carcinoma Ductal de Mama/metabolismo , Carcinoma Ductal de Mama/patologia , Carcinoma Lobular/genética , Carcinoma Lobular/metabolismo , Carcinoma Lobular/patologia , Proteínas de Transporte/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , DNA de Neoplasias/análise , Feminino , Proteína Adaptadora GRB7/metabolismo , Amplificação de Genes , Humanos , Técnicas Imunoenzimáticas , Hibridização in Situ Fluorescente , Metástase Linfática/patologia , Proteínas de Membrana/metabolismo , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Receptor ErbB-2/metabolismo , Estudos Retrospectivos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Taxa de Sobrevida
14.
Mol Cell Biol ; 23(22): 8124-36, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14585972

RESUMO

RanBP type proteins have been reported to increase the catalytic efficiency of the RanGAP-mediated GTPase reaction on Ran. Since the structure of the Ran-RanBP1-RanGAP complex showed RanBP1 to be located away from the active site, we reinvestigated the reaction using fluorescence spectroscopy under pre-steady-state conditions. We can show that RanBP1 indeed does not influence the rate-limiting step of the reaction, which is the cleavage of GTP and/or the release of product P(i). It does, however, influence the dynamics of the Ran-RanGAP interaction, its most dramatic effect being the 20-fold stimulation of the already very fast association reaction such that it is under diffusion control (4.5 x 10(8) M(-1) s(-1)). Having established a valuable kinetic system for the interaction analysis, we also found, in contrast to previous findings, that the highly conserved acidic C-terminal end of RanGAP is not required for the switch-off reaction. Rather, genetic experiments in Saccharomyces cerevisiae demonstrate a profound effect of the acidic tail on microtubule organization during mitosis. We propose that the acidic tail of RanGAP is required for a process during mitosis.


Assuntos
Proteínas Ativadoras de GTPase/química , Proteínas Ativadoras de GTPase/metabolismo , Proteínas Nucleares/química , Proteínas Nucleares/metabolismo , Proteína ran de Ligação ao GTP/química , Proteína ran de Ligação ao GTP/metabolismo , Sequência de Aminoácidos , Sítios de Ligação , Proteínas Ativadoras de GTPase/genética , Humanos , Técnicas In Vitro , Cinética , Substâncias Macromoleculares , Modelos Biológicos , Modelos Moleculares , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Proteínas Nucleares/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Schizosaccharomyces/genética , Schizosaccharomyces/metabolismo , Proteínas de Schizosaccharomyces pombe/química , Proteínas de Schizosaccharomyces pombe/genética , Proteínas de Schizosaccharomyces pombe/metabolismo , Deleção de Sequência , Homologia de Sequência de Aminoácidos , Espectrometria de Fluorescência , Proteína ran de Ligação ao GTP/genética
15.
EMBO J ; 22(5): 1088-100, 2003 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-12606574

RESUMO

Here, we analyse the RanGTPase system and its coupling to receptor-mediated nuclear transport. Our simulations predict nuclear RanGTP levels in HeLa cells to be very sensitive towards the cellular energy charge and to exceed the cytoplasmic concentration approximately 1000-fold. The steepness of the RanGTP gradient appears limited by both the cytoplasmic RanGAP concentration and the imperfect retention of nuclear RanGTP by nuclear pore complexes (NPCs), but not by the nucleotide exchange activity of RCC1. Neither RanBP1 nor the NPC localization of RanGAP has a significant direct impact on the RanGTP gradient. NTF2-mediated import of Ran appears to be the bottleneck for maximal capacity of Ran-driven nuclear transport. We show that unidirectional nuclear transport can be faithfully simulated without the assumption of a vectorial NPC passage; transport receptors only need to reversibly cross NPCs and switch their affinity for cargo in response to the RanGTP gradient. A significant RanGTP gradient after nuclear envelope (NE) breakdown can apparently exist only in large cytoplasm. This indicates that RanGTP gradients can provide positional information for mitotic spindle and NE assembly in early embryonic cells, but hardly any in small somatic cells.


Assuntos
Transporte Ativo do Núcleo Celular/fisiologia , Simulação por Computador , Proteína ran de Ligação ao GTP/metabolismo , Proteínas Ativadoras de GTPase/metabolismo , Guanosina Difosfato/metabolismo , Guanosina Trifosfato/metabolismo , Células HeLa , Humanos , Cinética , Poro Nuclear/metabolismo , Proteínas de Transporte Nucleocitoplasmático/metabolismo , beta Carioferinas/metabolismo
16.
Nature ; 415(6872): 662-6, 2002 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-11832950

RESUMO

GTPase-activating proteins (GAPs) increase the rate of GTP hydrolysis on guanine nucleotide-binding proteins by many orders of magnitude. Studies with Ras and Rho have elucidated the mechanism of GAP action by showing that their catalytic machinery is both stabilized by GAP binding and complemented by the insertion of a so-called 'arginine finger' into the phosphate-binding pocket. This has been proposed as a universal mechanism for GAP-mediated GTP hydrolysis. Ran is a nuclear Ras-related protein that regulates both transport between the nucleus and cytoplasm during interphase, and formation of the mitotic spindle and/or nuclear envelope in dividing cells. Ran-GTP is hydrolysed by the combined action of Ran-binding proteins (RanBPs) and RanGAP. Here we present the three-dimensional structure of a Ran-RanBP1-RanGAP ternary complex in the ground state and in a transition-state mimic. The structure and biochemical experiments show that RanGAP does not act through an arginine finger, that the basic machinery for fast GTP hydrolysis is provided exclusively by Ran and that correct positioning of the catalytic glutamine is essential for catalysis.


Assuntos
Arginina/metabolismo , Proteínas Ativadoras de GTPase/metabolismo , Guanosina Trifosfato/metabolismo , Proteína ran de Ligação ao GTP/metabolismo , Arginina/química , Domínio Catalítico , Cristalografia por Raios X , Escherichia coli , Proteínas Ativadoras de GTPase/química , Guanosina Trifosfato/química , Humanos , Hidrólise , Modelos Moleculares , Proteínas Nucleares/química , Proteínas Nucleares/metabolismo , Conformação Proteica , Estrutura Terciária de Proteína , Proteínas Recombinantes , Schizosaccharomyces/química , Schizosaccharomyces/metabolismo , Proteína ran de Ligação ao GTP/química
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