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1.
Transl Med UniSa ; 19: 66-81, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31360670

RESUMO

Seventy four Reference Sites of the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA) have been recognised by the European Commission in 2016 for their commitment to excellence in investing and scaling up innovative solutions for active and healthy ageing. The Reference Site Collaborative Network (RSCN) brings together the EIP on AHA Reference Sites awarded by the European Commission, and Candidate Reference Sites into a single forum. The overarching goals are to promote cooperation, share and transfer good practice and solutions in the development and scaling up of health and care strategies, policies and service delivery models, while at the same time supporting the action groups in their work. The RSCN aspires to be recognized by the EU Commission as the principal forum and authority representing all EIP on AHA Reference Sites. The RSCN will contribute to achieve the goals of the EIP on AHA by improving health and care outcomes for citizens across Europe, and the development of sustainable economic growth and the creation of jobs.

2.
Allergy ; 73(8): 1622-1631, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29569295

RESUMO

BACKGROUND: Multimorbidity in allergic airway diseases is well known, but no data exist about the daily dynamics of symptoms and their impact on work. To better understand this, we aimed to assess the presence and control of daily allergic multimorbidity (asthma, conjunctivitis, rhinitis) and its impact on work productivity using a mobile technology, the Allergy Diary. METHODS: We undertook a 1-year prospective observational study in which 4 210 users and 32 585 days were monitored in 19 countries. Five visual analogue scales (VAS) assessed the daily burden of the disease (i.e., global evaluation, nose, eyes, asthma and work). Visual analogue scale levels <20/100 were categorized as "Low" burden and VAS levels ≥50/100 as "High" burden. RESULTS: Visual analogue scales global measured levels assessing the global control of the allergic disease were significantly associated with allergic multimorbidity. Eight hypothesis-driven patterns were defined based on "Low" and "High" VAS levels. There were <0.2% days of Rhinitis Low and Asthma High or Conjunctivitis High patterns. There were 5.9% days with a Rhinitis High-Asthma Low pattern. There were 1.7% days with a Rhinitis High-Asthma High-Conjunctivitis Low pattern. A novel Rhinitis High-Asthma High-Conjunctivitis High pattern was identified in 2.9% days and had the greatest impact on uncontrolled VAS global measured and impaired work productivity. Work productivity was significantly correlated with VAS global measured levels. CONCLUSIONS: In a novel approach examining daily symptoms with mobile technology, we found considerable intra-individual variability of allergic multimorbidity including a previously unrecognized extreme pattern of uncontrolled multimorbidity.


Assuntos
Hipersensibilidade/epidemiologia , Aplicativos Móveis , Multimorbidade , Rinite/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Avaliação de Resultados da Assistência ao Paciente , Prevalência , Estudos Prospectivos , Projetos de Pesquisa , Adulto Jovem
3.
Allergy ; 73(1): 77-92, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28600902

RESUMO

The overarching goals of the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA) are to enable European citizens to lead healthy, active and independent lives whilst ageing. The EIP on AHA includes 74 Reference Sites. The aim of this study was to transfer innovation from an app developed by the MACVIA-France EIP on AHA reference site (Allergy Diary) to other reference sites. The phenotypic characteristics of rhinitis and asthma multimorbidity in adults and the elderly will be compared using validated information and communication technology (ICT) tools (i.e. the Allergy Diary and CARAT: Control of Allergic Rhinitis and Asthma Test) in 22 Reference Sites or regions across Europe. This will improve the understanding, assessment of burden, diagnosis and management of rhinitis in the elderly by comparison with an adult population. Specific objectives will be: (i) to assess the percentage of adults and elderly who are able to use the Allergy Diary, (ii) to study the phenotypic characteristics and treatment over a 1-year period of rhinitis and asthma multimorbidity at baseline (cross-sectional study) and (iii) to follow-up using visual analogue scale (VAS). This part of the study may provide some insight into the differences between the elderly and adults in terms of response to treatment and practice. Finally (iv) work productivity will be examined in adults.


Assuntos
Asma/epidemiologia , Rinite Alérgica/epidemiologia , Fatores Etários , Idoso , Tomada de Decisão Clínica , Comorbidade , Avaliação Geriátrica , Humanos , Avaliação de Resultados em Cuidados de Saúde , Vigilância da População
4.
J Nutr Health Aging ; 21(1): 92-104, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27999855

RESUMO

The Strategic Implementation Plan of the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA) proposed six Action Groups. After almost three years of activity, many achievements have been obtained through commitments or collaborative work of the Action Groups. However, they have often worked in silos and, consequently, synergies between Action Groups have been proposed to strengthen the triple win of the EIP on AHA. The paper presents the methodology and current status of the Task Force on EIP on AHA synergies. Synergies are in line with the Action Groups' new Renovated Action Plan (2016-2018) to ensure that their future objectives are coherent and fully connected. The outcomes and impact of synergies are using the Monitoring and Assessment Framework for the EIP on AHA (MAFEIP). Eight proposals for synergies have been approved by the Task Force: Five cross-cutting synergies which can be used for all current and future synergies as they consider overarching domains (appropriate polypharmacy, citizen empowerment, teaching and coaching on AHA, deployment of synergies to EU regions, Responsible Research and Innovation), and three cross-cutting synergies focussing on current Action Group activities (falls, frailty, integrated care and chronic respiratory diseases).


Assuntos
Envelhecimento , Comportamentos Relacionados com a Saúde , População Branca , Acidentes por Quedas/prevenção & controle , Idoso , Idoso de 80 Anos ou mais , Doença Crônica , Comportamento Cooperativo , Europa (Continente) , Idoso Fragilizado , Humanos , Múltiplas Afecções Crônicas , Inovação Organizacional , Polimedicação , Inquéritos e Questionários
5.
J Frailty Aging ; 5(4): 233-241, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27883170

RESUMO

The Région Languedoc Roussillon is the umbrella organisation for an interconnected and integrated project on active and healthy ageing (AHA). It covers the 3 pillars of the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA): (A) Prevention and health promotion, (B) Care and cure, (C) and (D) Active and independent living of elderly people. All sub-activities (poly-pharmacy, falls prevention initiative, prevention of frailty, chronic respiratory diseases, chronic diseases with multimorbidities, chronic infectious diseases, active and independent living and disability) have been included in MACVIA-LR which has a strong political commitment and involves all stakeholders (public, private, patients, policy makers) including CARSAT-LR and the Eurobiomed cluster. It is a Reference Site of the EIP on AHA. The framework of MACVIA-LR has the vision that the prevention and management of chronic diseases is essential for the promotion of AHA and for the reduction of handicap. The main objectives of MACVIA-LR are: (i) to develop innovative solutions for a network of Living labs in order to reduce avoidable hospitalisations and loss of autonomy while improving quality of life, (ii) to disseminate the innovation. The three years of MACVIA-LR activities are reported in this paper.


Assuntos
Envelhecimento , Política de Saúde , Promoção da Saúde , Vida Independente , Medicina Preventiva , Acidentes por Quedas/prevenção & controle , Idoso , Idoso de 80 Anos ou mais , Doença Crônica , Comorbidade , União Europeia , França , Hospitalização , Humanos , Múltiplas Afecções Crônicas , Saúde Bucal , Autonomia Pessoal , Polimedicação , Qualidade de Vida , Doenças Respiratórias
7.
J Nutr Health Aging ; 19(9): 955-60, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26482699

RESUMO

Health is a multi-dimensional concept, capturing how people feel and function. The broad concept of Active and Healthy Ageing was proposed by the World Health Organisation (WHO) as the process of optimizing opportunities for health to enhance quality of life as people age. It applies to both individuals and population groups. A universal Active and Healthy Ageing definition is not available and it may differ depending on the purpose of the definition and/or the questions raised. While the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA) has had a major impact, a definition of Active and Healthy Ageing is urgently needed. A meeting was organised in Montpellier, France, October 20-21, 2014 as the annual conference of the EIP on AHA Reference Site MACVIA-LR (Contre les Maladies Chroniques pour un Vieillissement Actif en Languedoc Roussillon) to propose an operational definition of Active and Healthy Ageing including tools that may be used for this. The current paper describes the rationale and the process by which the aims of the meeting will be reached.


Assuntos
Envelhecimento , Doença Crônica , Saúde , Vida Independente , Qualidade de Vida , Exercício Físico , França , Humanos , Meio Social
9.
Stud Health Technol Inform ; 210: 296-300, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25991153

RESUMO

This paper has two aims: 1) to describe the tele-expertise system implemented in the Montpellier University Hospital (France) in order to optimize antimicrobial use 2) to analyze the prescribers' adherence to this system. For the second purpose, an observational prospective study was conducted for 12 months. Data were collected from counselling advices, which were notified in the electronic medical records. 1386 tele-expertise actions were performed. Among them, 87% were made without clinical evaluation at the bedside. The prescribers' adherence rate to a diagnosis was 79%. For the therapeutic requests, 87% of answers were fully followed. The results outline how the tele-expertise system enables both infectious disease specialists and prescribers to make better decisions in particular cases.


Assuntos
Antibacterianos/uso terapêutico , Infecções Bacterianas/tratamento farmacológico , Sistemas de Apoio a Decisões Clínicas/estatística & dados numéricos , Registros Eletrônicos de Saúde/estatística & dados numéricos , Adesão à Medicação/estatística & dados numéricos , Consulta Remota/estatística & dados numéricos , França , Hospitais Universitários/estatística & dados numéricos , Humanos , Sistemas de Registro de Ordens Médicas/organização & administração , Sistemas de Registro de Ordens Médicas/estatística & dados numéricos
10.
Stud Health Technol Inform ; 210: 531-5, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25991204

RESUMO

The goal of this study was to examine the perceived usefulness and the perceived ease of use of a Hospital Information System (HIS) for the care staff. We administrated a questionnaire composed of open-end and closed questions. As results, the perceived usefulness and ease of use are correlated with medical occupations. Content analysis of open questions highlights three factors influencing these constructs: ergonomics, errors in the documenting process and insufficient compatibility with the medical department or the occupation. While the results are consistent with literature, they show medical occupations do not report the same low rate of perceived usefulness and of ease of use. The main explanation consists in the medical risk in the prescription process for anesthesiologists, surgeons and physicians.


Assuntos
Centros Médicos Acadêmicos/estatística & dados numéricos , Atitude do Pessoal de Saúde , Atitude Frente aos Computadores , Sistemas de Informação Hospitalar/estatística & dados numéricos , Uso Significativo/estatística & dados numéricos , Interface Usuário-Computador , Revisão da Utilização de Recursos de Saúde , França
11.
Rev Med Interne ; 36(10): 677-89, 2015 Oct.
Artigo em Francês | MEDLINE | ID: mdl-26003377

RESUMO

Drug-induced adverse effects are one of the main avoidable causes of hospitalization in older people. Numerous lists of potentially inappropriate medications for older people have been published, as national and international guidelines for appropriate prescribing in numerous diseases and for different age categories. The present review describes the general rules for an appropriate prescribing in older people and summarizes, for the main conditions encountered in older people, medications that are too often under-prescribed, the precautions of use of the main drugs that induce adverse effects, and drugs for which the benefit to risk ratio is unfavourable in older people. All these data are assembled in educational tables designed to be printed in a practical pocket format and used in daily practice by prescribers, whether physicians, surgeons or pharmacists.


Assuntos
Idoso , Prescrições de Medicamentos , Padrões de Prática Médica , Fatores Etários , Idoso de 80 Anos ou mais , Prescrições de Medicamentos/normas , Prescrições de Medicamentos/estatística & dados numéricos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/epidemiologia , Humanos , Prescrição Inadequada/prevenção & controle , Prescrição Inadequada/estatística & dados numéricos , Erros de Medicação/prevenção & controle , Erros de Medicação/estatística & dados numéricos , Padrões de Prática Médica/estatística & dados numéricos
12.
Thorax ; 70(6): 595-7, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25616486

RESUMO

Prenatal and peri-natal events play a fundamental role in health, development of diseases and ageing (Developmental Origins of Health and Disease (DOHaD)). Research on the determinants of active and healthy ageing is a priority to: (i) inform strategies for reducing societal and individual costs of an ageing population and (ii) develop effective novel prevention strategies. It is important to compare the trajectories of respiratory diseases with those of other chronic diseases.


Assuntos
Envelhecimento , Desenvolvimento Infantil , Doença Crônica/prevenção & controle , Desenvolvimento Fetal , Adulto , Idoso , Doença de Alzheimer/prevenção & controle , Asma/prevenção & controle , Depressão/prevenção & controle , Diabetes Mellitus/prevenção & controle , Comportamento Alimentar , Feminino , Humanos , Hipersensibilidade/prevenção & controle , Lactente , Recém-Nascido , Auditoria Médica , Pessoa de Meia-Idade , Osteoporose/prevenção & controle , Fatores de Risco
13.
AMIA Annu Symp Proc ; 2015: 1001-7, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26958237

RESUMO

The goal of this study was to examine the perceived usefulness, the perceived ease of use and the perceived behavioral control of a Hospital Information System (HIS) for the care staff. We administrated a questionnaire composed of open-end and closed questions, based on the main concepts of Technology Acceptance Model. As results, the perceived usefulness, ease of use and behavioral control (self-efficacy and organizational support) are correlated with medical occupations. As an example, we found that a half of the medical secretaries consider the HIS is ease of use, at the opposite to the anesthesiologists, surgeons and physicians. Medical secretaries reported also the highest rate of PBC and a high rate of PU. Pharmacists reported the highest rate of PU but a low rate of PBC, which is similar to the rate of the surgeons and physicians. Content analysis of open questions highlights factors influencing these constructs: ergonomics, errors in the documenting process, insufficient compatibility with the medical department or the occupational group. Consequently, we suggest that the gap between the perceptions of the different occupational groups may be explained by the use of different modules and by interdependency of the care stare staff.


Assuntos
Atitude do Pessoal de Saúde , Atitude Frente aos Computadores , Sistemas de Informação Hospitalar , Hospitais Universitários , Humanos , Médicos
14.
Eur Respir J ; 44(2): 304-23, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24925919

RESUMO

The objective of Integrated Care Pathways for Airway Diseases (AIRWAYS-ICPs) is to launch a collaboration to develop multi-sectoral care pathways for chronic respiratory diseases in European countries and regions. AIRWAYS-ICPs has strategic relevance to the European Union Health Strategy and will add value to existing public health knowledge by: 1) proposing a common framework of care pathways for chronic respiratory diseases, which will facilitate comparability and trans-national initiatives; 2) informing cost-effective policy development, strengthening in particular those on smoking and environmental exposure; 3) aiding risk stratification in chronic disease patients, using a common strategy; 4) having a significant impact on the health of citizens in the short term (reduction of morbidity, improvement of education in children and of work in adults) and in the long-term (healthy ageing); 5) proposing a common simulation tool to assist physicians; and 6) ultimately reducing the healthcare burden (emergency visits, avoidable hospitalisations, disability and costs) while improving quality of life. In the longer term, the incidence of disease may be reduced by innovative prevention strategies. AIRWAYSICPs was initiated by Area 5 of the Action Plan B3 of the European Innovation Partnership on Active and Healthy Ageing. All stakeholders are involved (health and social care, patients, and policy makers).


Assuntos
Transtornos Respiratórios/terapia , Envelhecimento , Asma/terapia , Tomada de Decisões , Europa (Continente) , União Europeia , Guias como Assunto , Humanos , Cooperação Internacional , Área Carente de Assistência Médica , Doença Pulmonar Obstrutiva Crônica/terapia , Qualidade de Vida , Rinite/terapia , Fatores de Risco , Organização Mundial da Saúde
15.
Proc Natl Acad Sci U S A ; 98(11): 6003-8, 2001 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-11353835

RESUMO

CheY, a response regulator protein in bacterial chemotaxis, serves as a prototype for the analysis of response regulator function in two-component signal transduction. Phosphorylation of a conserved aspartate at the active site mediates a conformational change at a distal signaling surface that modulates interactions with the flagellar motor component FliM, the sensor kinase CheA, and the phosphatase CheZ. The objective of this study was to probe the conformational coupling between the phosphorylation site and the signaling surface of CheY in the reverse direction by quantifying phosphorylation activity in the presence and absence of peptides of CheA, CheZ, and FliM that specifically interact with CheY. Binding of these peptides dramatically impacted autophosphorylation of CheY by small molecule phosphodonors, which is indicative of reverse signal propagation in CheY. Autodephosphorylation and substrate affinity, however, were not significantly affected. Kinetic characterization of several CheY mutants suggested that conserved residues Thr-87, Tyr-106, and Lys-109, implicated in the activation mechanism, are not essential for conformational coupling. These findings provide structural and conceptual insights into the mechanism of CheY activation. Our results are consistent with a multistate thermodynamic model of response regulator activation.


Assuntos
Proteínas de Bactérias/metabolismo , Quimiotaxia/fisiologia , Proteínas de Membrana/metabolismo , Sequência de Aminoácidos , Cinética , Proteínas de Membrana/química , Proteínas de Membrana/genética , Proteínas Quimiotáticas Aceptoras de Metil , Dados de Sequência Molecular , Mutagênese , Fosforilação , Conformação Proteica , Relação Estrutura-Atividade
16.
J Biol Chem ; 276(21): 18478-84, 2001 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-11278903

RESUMO

CheY is a response regulator in the well studied two-component system that mediates bacterial chemotaxis. Phosphorylation of CheY at Asp(57) enhances its interaction with the flagellar motor. Asn(59) is located near the phosphorylation site, and possible roles this residue may play in CheY function were explored by mutagenesis. Cells containing CheY59NR or CheY59NH exhibited hyperactive phenotypes (clockwise flagellar rotation), and CheY59NR was characterized biochemically. A continuous enzyme-linked spectroscopic assay that monitors P(i) concentration was the primary method for kinetic analysis of phosphorylation and dephosphorylation. CheY59NR autodephosphorylated at the same rate as wild-type CheY and phosphorylated similarly to wild type with acetyl phosphate and faster (4-14x) with phosphoramidate and monophosphoimidazole. CheY59NR was extremely resistant to CheZ, requiring at least 250 times more CheZ than wild-type CheY to achieve the same dephosphorylation rate enhancement, whereas CheY59NA was CheZ-sensitive. However, several independent approaches demonstrated that CheY59NR bound tightly to CheZ. A submicromolar K(d) for CheZ binding to CheY59NR-P or CheY.BeF(3)(-) was inferred from fluorescence anisotropy measurements of fluoresceinated-CheZ. A complex between CheY59NR-P and CheZ was isolated by analytical gel filtration, and the elution position from the column was indistinguishable from that of the CheZ dimer. Therefore, we were not able to detect large CheY-P.CheZ complexes that have been inferred using other methods. Possible structural explanations for the specific inhibition of CheZ activity as a result of the arginyl substitution at CheY position 59 are discussed.


Assuntos
Proteínas de Bactérias , Quimiotaxia , Proteínas de Membrana/metabolismo , Escherichia coli , Proteínas de Escherichia coli , Proteínas Quimiotáticas Aceptoras de Metil , Fosforilação
17.
J Bacteriol ; 182(12): 3544-52, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10852888

RESUMO

The Escherichia coli CheZ protein stimulates dephosphorylation of CheY, a response regulator in the chemotaxis signal transduction pathway, by an unknown mechanism. Genetic analysis of CheZ has lagged behind biochemical and biophysical characterization. To identify putative regions of functional importance in CheZ, we subjected cheZ to random mutagenesis and isolated 107 nonchemotactic CheZ mutants. Missense mutations clustered in six regions of cheZ, whereas nonsense and frameshift mutations were scattered reasonably uniformly across the gene. Intragenic complementation experiments showed restoration of swarming activity when compatible plasmids containing genes for the truncated CheZ(1-189) peptide and either CheZA65V, CheZL90S, or CheZD143G were both present, implying the existence of at least two independent functional domains in each chain of the CheZ dimer. Six mutant CheZ proteins, one from each cluster of loss-of-function missense mutations, were purified and characterized biochemically. All of the tested mutant proteins were defective in their ability to dephosphorylate CheY-P, with activities ranging from 0.45 to 16% of that of wild-type CheZ. There was good correlation between the phosphatase activity of CheZ and the ability to form large chemically cross-linked complexes with CheY in the presence of the CheY phosphodonor acetyl phosphate. In consideration of both the genetic and biochemical data, the most severe functional impairments in this set of CheZ mutants seemed to be concentrated in regions which are located in a proposed large N-terminal domain of the CheZ protein.


Assuntos
Proteínas de Bactérias , Quimiotaxia/fisiologia , Escherichia coli/genética , Escherichia coli/fisiologia , Proteínas de Membrana/genética , Mutação , Sequência de Aminoácidos , Proteínas de Escherichia coli , Teste de Complementação Genética , Espectrometria de Massas , Proteínas de Membrana/química , Proteínas de Membrana/metabolismo , Proteínas Quimiotáticas Aceptoras de Metil , Dados de Sequência Molecular , Fosforilação , Ligação Proteica , Alinhamento de Sequência
18.
J Biol Chem ; 275(26): 19752-8, 2000 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-10748173

RESUMO

In Escherichia coli, swimming behavior is mediated by the phosphorylation state of the response regulator CheY. In its active, phosphorylated form, CheY exhibits enhanced binding to a switch component, FliM, at the flagellar motor, which induces a change from counterclockwise to clockwise flagellar rotation. When Ile(95) of CheY is replaced by a valine, increased clockwise rotation correlates with enhanced binding to FliM. A possible explanation for the hyperactivity of this mutant is that residue 95 affects the conformation of nearby residues that potentially interact with FliM. In order to assess this possibility directly, the crystal structure of CheY95IV was determined. We found that CheY95IV is structurally almost indistinguishable from wild-type CheY. Several other mutants with substitutions at position 95 were characterized to establish the structural requirements for switch binding and clockwise signaling at this position and to investigate a general relationship between the two properties. The various rotational phenotypes of these mutants can be explained solely by the amount of phosphorylated CheY bound to the switch, which was inferred from the phosphorylation properties of the mutant CheY proteins and their binding affinities to FliM. Combined genetic, biochemical, and crystallographic results suggest that residue 95 itself is critical in mediating the surface complementarity between CheY and FliM.


Assuntos
Quimiotaxia , Escherichia coli/citologia , Escherichia coli/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Cristalografia por Raios X , Proteínas de Escherichia coli , Flagelos , Cinética , Proteínas de Membrana/química , Proteínas de Membrana/metabolismo , Proteínas Quimiotáticas Aceptoras de Metil , Dados de Sequência Molecular , Movimento , Mutagênese , Peptídeos/metabolismo , Fenótipo , Fosforilação , Plasmídeos , Ligação Proteica , Conformação Proteica , Tirosina/química
19.
Mol Microbiol ; 34(5): 915-25, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10594818

RESUMO

The site of phosphorylation of the chemotaxis response regulator CheY is aspartate 57. When Asp-57 is replaced with an asparagine, the resultant protein can be phosphorylated at an alternative site. We report here that phosphorylation of this mutant protein, CheY D57N, at the alternative site affords the protein activity in vivo in the absence of CheZ. Using a direct phosphopeptide mapping approach, we identified the alternate phosphorylation site as serine 56. Introduction of a Ser-->Ala substitution at this position in wild-type CheY had no effect on function. However, replacement of Ser-56 with Ala in CheY D57N abrogated the activity seen in vivo for the CheY D57N single mutant protein, and no phosphorylation of the CheY S56A/D57N double mutant protein was observed in vitro. Construction and analysis of double mutants CheY D57N/T87A and CheY D57N/K109R, which were both inactive, suggested that phosphorylation at Ser-56 or Asp-57 may activate the protein by similar mechanisms. In contrast to CheY D57N, mutant CheY D57E displayed no activity in vivo, despite its ability to be phosphorylated in vitro. Acid-base stability analysis indicated that CheY D57E phosphorylates on an acidic residue, presumably Glu-57. These data suggest that a key determinant of the ability of a phosphoryl group to activate CheY is proximity to the hydrophobic core of the protein, with consequent opportunity to reposition key residues, irrespective of the chemical nature of the linkage attaching the phosphoryl group to CheY.


Assuntos
Proteínas de Bactérias , Escherichia coli/genética , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Mutação , Substituição de Aminoácidos , Quimiotaxia , Escherichia coli/fisiologia , Proteínas de Escherichia coli , Flagelos/fisiologia , Proteínas de Membrana/fisiologia , Proteínas Quimiotáticas Aceptoras de Metil , Mapeamento de Peptídeos/métodos , Fosforilação , Fosfosserina/metabolismo , Proteínas Quinases/metabolismo , Transdução de Sinais
20.
Trends Microbiol ; 7(1): 16-22, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10068993

RESUMO

In Escherichia coli chemotaxis, the switch from counterclockwise to clockwise rotation of the flagella occurs as a result of binding of the phosphorylated CheY protein to the base of the flagellum. Analysis of CheY variants has provided a picture of the surface of CheY that undergoes conformational shifts, as a result of phosphorylation, to interact directly with the flagellum. Whether phospho-CheY binding and flagellar switching are sequential steps or can occur in a concerted fashion has yet to be determined.


Assuntos
Proteínas de Bactérias/metabolismo , Quimiotaxia , Escherichia coli/fisiologia , Proteínas de Membrana/metabolismo , Transdução de Sinais , Escherichia coli/genética , Proteínas de Escherichia coli , Flagelos/metabolismo , Proteínas de Membrana/química , Proteínas de Membrana/genética , Proteínas Quimiotáticas Aceptoras de Metil , Modelos Biológicos
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