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1.
Patient ; 17(3): 229-237, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38421583

RESUMO

Interest in using patient preference (PP) data alongside traditional economic models in health technology assessment (HTA) is growing, including using PP data to quantify non-health benefits. However, this is limited by a lack of standardised methods. In this article, we describe a method for using discrete choice experiment (DCE) data to estimate the value of non-health benefits in terms of quality-adjusted survival equivalence (QASE), which is consistent with the concept of value prevalent among HTA agencies. We describe how PP data can be used to estimate QASE, assess the ability to test the face-validity of QASE estimates of changes in mode of administration calculated from five published DCE oncology studies and review the methodological and normative considerations associated with using QASE to support HTA. We conclude that QASE may have some methodological advantages over alternative methods, but this requires DCEs to estimate second-order effects between length and quality of life. In addition, empirical work has yet to be undertaken to substantiate this advantage and demonstrate the validity of QASE. Further work is also required to align QASE with normative objectives of HTA agencies. Estimating QASE would also have implications for the conduct of DCEs, including standardising and defining more clear attribute definitions.


Assuntos
Preferência do Paciente , Anos de Vida Ajustados por Qualidade de Vida , Avaliação da Tecnologia Biomédica , Humanos , Qualidade de Vida , Comportamento de Escolha , Análise Custo-Benefício
2.
PEC Innov ; 3: 100212, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37743956

RESUMO

Objective: Advancements in diagnostics and treatment options for cardiac amyloidosis have improved patient outcomes, yet few patient education materials exist to help patients understand the disease and diagnosis process. We sought to develop and evaluate a set of plain language, patient-centered infographics describing the condition and common diagnostic tests. Methods: Using health literacy best practices, we developed 7 infographics which were further revised based on multilevel stakeholder feedback. To evaluate the materials, we recruited 100 patients from healthcare settings in Chicago, IL; participants completed a web-assisted interview during which they were randomized 1:1 to first view either our infographics or a standard material. Participants completed a knowledge assessment on their assigned material and subsequently reported impressions of both materials. Results: No differences were found between study arms in knowledge. The infographics took significantly less time to read and were more highly rated by participants in terms of appearance and understandability. Over two-thirds of participants preferred the infographics to the standard. Conclusions: The infographics created may improve the learning process about a complex condition and diagnosis process unknown to most adults. Innovation: These infographics are the first of their kind for cardiac amyloidosis and were created using health literacy best practices.

3.
Nat Commun ; 12(1): 2298, 2021 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-33863903

RESUMO

Neutrophils play fundamental roles in innate immune response, shape adaptive immunity, and are a potentially causal cell type underpinning genetic associations with immune system traits and diseases. Here, we profile the binding of myeloid master regulator PU.1 in primary neutrophils across nearly a hundred volunteers. We show that variants associated with differential PU.1 binding underlie genetically-driven differences in cell count and susceptibility to autoimmune and inflammatory diseases. We integrate these results with other multi-individual genomic readouts, revealing coordinated effects of PU.1 binding variants on the local chromatin state, enhancer-promoter contacts and downstream gene expression, and providing a functional interpretation for 27 genes underlying immune traits. Collectively, these results demonstrate the functional role of PU.1 and its target enhancers in neutrophil transcriptional control and immune disease susceptibility.


Assuntos
Doenças Autoimunes/genética , Elementos Facilitadores Genéticos/genética , Regulação da Expressão Gênica/imunologia , Neutrófilos/imunologia , Proteínas Proto-Oncogênicas/metabolismo , Transativadores/metabolismo , Adulto , Idoso , Doenças Autoimunes/imunologia , Cromatina/metabolismo , Sequenciamento de Cromatina por Imunoprecipitação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neutrófilos/metabolismo , Regiões Promotoras Genéticas/genética , Locos de Características Quantitativas/genética , Locos de Características Quantitativas/imunologia , Adulto Jovem
4.
Clin Cancer Res ; 25(11): 3384-3391, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30846478

RESUMO

PURPOSE: Squamous cell carcinoma (SCC) of the skin is the leading cause of death in patients with the severe generalized form of the genetic disease recessive dystrophic epidermolysis bullosa (RDEB). Although emerging data are identifying why patients suffer this fatal complication, therapies for treatment of RDEB SCC are in urgent need.Experimental Design: We previously identified polo-like kinase 1 (PLK1) as a therapeutic target in skin SCC, including RDEB SCC. Here, we undertake a screen of 6 compounds originally designated as PLK1 inhibitors, and detail the efficacy of the lead compound, the multipathway allosteric inhibitor ON-01910, for targeting RDEB SCC in vitro and in vivo. RESULTS: ON-01910 (or rigosertib) exhibited significant specificity for RDEB SCC: in culture rigosertib induced apoptosis in 10 of 10 RDEB SCC keratinocyte populations while only slowing the growth of normal primary skin cells at doses 2 orders of magnitude higher. Furthermore, rigosertib significantly inhibited the growth of two RDEB SCC in murine xenograft studies with no apparent toxicity. Mechanistically, rigosertib has been shown to inhibit multiple signaling pathways. Comparison of PLK1 siRNA with MEK inhibition, AKT inhibition, and the microtubule-disrupting agent vinblastine in RDEB SCC shows that only PLK1 reduction exhibits a similar sensitivity profile to rigosertib. CONCLUSIONS: These data support a "first in RDEB" phase II clinical trial of rigosertib to assess tumor targeting in patients with late stage, metastatic, and/or unresectable SCC.


Assuntos
Antineoplásicos/uso terapêutico , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/etiologia , Epidermólise Bolhosa Distrófica/complicações , Epidermólise Bolhosa Distrófica/genética , Glicina/análogos & derivados , Neoplasias Cutâneas/tratamento farmacológico , Neoplasias Cutâneas/etiologia , Sulfonas/uso terapêutico , Antineoplásicos/farmacologia , Apoptose , Carcinoma de Células Escamosas/diagnóstico , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Técnicas de Silenciamento de Genes , Genes Recessivos , Glicina/farmacologia , Glicina/uso terapêutico , Humanos , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Terapia de Alvo Molecular , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , RNA Mensageiro , RNA Interferente Pequeno , Neoplasias Cutâneas/diagnóstico , Sulfonas/farmacologia , Quinase 1 Polo-Like
5.
Cell ; 167(5): 1398-1414.e24, 2016 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-27863251

RESUMO

Characterizing the multifaceted contribution of genetic and epigenetic factors to disease phenotypes is a major challenge in human genetics and medicine. We carried out high-resolution genetic, epigenetic, and transcriptomic profiling in three major human immune cell types (CD14+ monocytes, CD16+ neutrophils, and naive CD4+ T cells) from up to 197 individuals. We assess, quantitatively, the relative contribution of cis-genetic and epigenetic factors to transcription and evaluate their impact as potential sources of confounding in epigenome-wide association studies. Further, we characterize highly coordinated genetic effects on gene expression, methylation, and histone variation through quantitative trait locus (QTL) mapping and allele-specific (AS) analyses. Finally, we demonstrate colocalization of molecular trait QTLs at 345 unique immune disease loci. This expansive, high-resolution atlas of multi-omics changes yields insights into cell-type-specific correlation between diverse genomic inputs, more generalizable correlations between these inputs, and defines molecular events that may underpin complex disease risk.


Assuntos
Epigenômica , Doenças do Sistema Imunitário/genética , Monócitos/metabolismo , Neutrófilos/metabolismo , Linfócitos T/metabolismo , Transcrição Gênica , Adulto , Idoso , Processamento Alternativo , Feminino , Predisposição Genética para Doença , Células-Tronco Hematopoéticas/metabolismo , Código das Histonas , Humanos , Masculino , Pessoa de Meia-Idade , Locos de Características Quantitativas , Adulto Jovem
6.
Postgrad Med ; 128(5): 502-15, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27166559

RESUMO

Chronic pain substantially impacts patient function and quality of life and is a burden to society at large in terms of increased health care utilization and loss of productivity. As a result, there is an increasing recognition of chronic pain as a public health crisis. However, there remains wide variability in clinical practices related to the prevention, assessment, and treatment of chronic pain. Certain fundamental aspects of chronic pain are often neglected including the contribution of the psychological, social, and contextual factors associated with chronic pain. Also commonly overlooked is the importance of understanding the likely neurobiological mechanism(s) of the presenting pain and how they can guide treatment selection. Finally, physicians may not recognize the value of using electronic medical records to systematically capture data on pain and its impact on mood, function, and sleep. Such data can be used to monitor onset and maintenance of treatments effects at the patient level and evaluate costs at the systems level. In this review we explain how these factors play a critical role in the development of a coordinated, evidence-based treatment approach tailored to meet specific needs of the patient. We also discuss some practical approaches and techniques that can be implemented by clinicians in order to enhance the assessment and management of individuals with chronic pain in primary care settings.


Assuntos
Analgésicos Opioides/uso terapêutico , Dor Crônica/terapia , Manejo da Dor/métodos , Atenção Primária à Saúde/métodos , Analgésicos não Narcóticos/uso terapêutico , Anti-Inflamatórios não Esteroides/uso terapêutico , Dor Crônica/classificação , Dor Crônica/etiologia , Terapias Complementares , Fibromialgia/terapia , Humanos , Neuralgia/terapia , Dor Nociceptiva/terapia
8.
PLoS One ; 10(9): e0137639, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26380979

RESUMO

Recessive dystrophic epidermolysis bullosa (RDEB) is caused by mutations in COL7A1 resulting in reduced or absent type VII collagen, aberrant anchoring fibril formation and subsequent dermal-epidermal fragility. Here, we identify a significant decrease in PLOD3 expression and its encoded protein, the collagen modifying enzyme lysyl hydroxylase 3 (LH3), in RDEB. We show abundant LH3 localising to the basement membrane in normal skin which is severely depleted in RDEB patient skin. We demonstrate expression is in-part regulated by endogenous type VII collagen and that, in agreement with previous studies, even small reductions in LH3 expression lead to significantly less secreted LH3 protein. Exogenous type VII collagen did not alter LH3 expression in cultured RDEB keratinocytes and we show that RDEB patients receiving bone marrow transplantation who demonstrate significant increase in type VII collagen do not show increased levels of LH3 at the basement membrane. Our data report a direct link between LH3 and endogenous type VII collagen expression concluding that reduction of LH3 at the basement membrane in patients with RDEB will likely have significant implications for disease progression and therapeutic intervention.


Assuntos
Membrana Basal/enzimologia , Membrana Basal/patologia , Epidermólise Bolhosa Distrófica/enzimologia , Epidermólise Bolhosa Distrófica/patologia , Pró-Colágeno-Lisina 2-Oxoglutarato 5-Dioxigenase/análise , Membrana Basal/metabolismo , Transplante de Medula Óssea , Células Cultivadas , Colágeno Tipo VII/análise , Colágeno Tipo VII/metabolismo , Epidermólise Bolhosa Distrófica/metabolismo , Epidermólise Bolhosa Distrófica/terapia , Humanos , Queratinócitos/enzimologia , Queratinócitos/metabolismo , Queratinócitos/patologia , Pró-Colágeno-Lisina 2-Oxoglutarato 5-Dioxigenase/metabolismo , Mapas de Interação de Proteínas , Pele/enzimologia , Pele/metabolismo , Pele/patologia
9.
Am J Pathol ; 185(9): 2354-63, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26212909

RESUMO

NF-κB signaling plays a crucial role in regulating proliferation and differentiation in the epidermis. Alterations in the NF-κB pathway can lead to skin pathologies with a significant burden to human health such as psoriasis and cutaneous squamous cell carcinoma (cSCC). Caspase recruitment domain (CARD)-containing scaffold proteins are key regulators of NF-κB signaling by providing a link between membrane receptors and NF-κB transcriptional subunits. Mutations in the CARD family member, CARD14, have been identified in patients with the inflammatory skin diseases psoriasis and pityriasis rubra pilaris. Here, we describe that the gene coding for another CARD scaffold protein, CARD11, is mutated in more than 38% of 111 cSCCs, and show that novel variants outside of the coiled-coil domain lead to constitutively activated NF-κB signaling. CARD11 protein expression was detectable in normal skin and increased in all cSCCs tested. CARD11 mRNA levels were comparable with CARD14 in normal skin and CARD11 mRNA was increased in cSCC. In addition, we identified CARD11 mutations in peritumoral and sun-exposed skin, suggesting that CARD11-mediated alterations in NF-κB signaling may be an early event in the development of cSCC.


Assuntos
Proteínas Adaptadoras de Sinalização CARD/genética , Regulação Neoplásica da Expressão Gênica , Predisposição Genética para Doença/genética , Guanilato Ciclase/genética , Mutação , NF-kappa B/metabolismo , Neoplasias de Células Escamosas/genética , Neoplasias Cutâneas/genética , Células Cultivadas , Epiderme/patologia , Humanos , Neoplasias Cutâneas/patologia
10.
J Invest Dermatol ; 134(10): 2630-2638, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24662767

RESUMO

Cutaneous SCC (cSCC) is the most frequently occuring skin cancer with metastatic potential and can manifest rapidly as a common side effect in patients receiving systemic kinase inhibitors. Here, we use massively parallel exome and targeted level sequencing of 132 sporadic cSCCs and of 39 squamoproliferative lesions and cSCCs arising in patients receiving the BRAF inhibitor vemurafenib, as well as 10 normal skin samples, to identify NOTCH1 mutation as an early event in squamous cell carcinogenesis. Bisected vemurafenib-induced lesions revealed surprising heterogeneity with different activating HRAS and NOTCH1 mutations identified in two halves of the same cSCC, suggesting polyclonal origin. Immunohistochemical analysis using an antibody specific to nuclear NOTCH1 correlates with mutation status in sporadic cSCCs, and regions of NOTCH1 loss or downregulation are frequently observed in normal-looking skin. Our data indicate that NOTCH1 acts as a gatekeeper in human cSCC.


Assuntos
Carcinogênese/genética , Carcinoma de Células Escamosas/genética , Mutação/genética , Receptor Notch1/genética , Transdução de Sinais/genética , Neoplasias Cutâneas/genética , Idoso , Idoso de 80 Anos ou mais , Biópsia , Carcinogênese/patologia , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Estudos de Casos e Controles , Regulação para Baixo , Feminino , Humanos , Indóis/uso terapêutico , Masculino , Pessoa de Meia-Idade , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Receptor Notch1/metabolismo , Receptores Notch/genética , Receptores Notch/metabolismo , Transdução de Sinais/fisiologia , Pele/metabolismo , Pele/patologia , Dermatopatias/tratamento farmacológico , Dermatopatias/metabolismo , Dermatopatias/patologia , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/patologia , Sulfonamidas/uso terapêutico , Vemurafenib
11.
J Cell Sci ; 127(Pt 4): 740-51, 2014 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-24357722

RESUMO

Type VII collagen is the main component of anchoring fibrils, structures that are integral to basement membrane homeostasis in skin. Mutations in the gene encoding type VII collagen COL7A1 cause recessive dystrophic epidermolysis bullosa (RDEB) an inherited skin blistering condition complicated by frequent aggressive cutaneous squamous cell carcinoma (cSCC). OATP1B3, which is encoded by the gene SLCO1B3, is a member of the OATP (organic anion transporting polypeptide) superfamily responsible for transporting a wide range of endogenous and xenobiotic compounds. OATP1B3 expression is limited to the liver in healthy tissues, but is frequently detected in multiple cancer types and is reported to be associated with differing clinical outcome. The mechanism and functional significance of tumour-specific expression of OATP1B3 has yet to be determined. Here, we identify SLCO1B3 expression in tumour keratinocytes isolated from RDEB and UV-induced cSCC and demonstrate that SLCO1B3 expression and promoter activity are modulated by type VII collagen. We show that reduction of SLCO1B3 expression upon expression of full-length type VII collagen in RDEB cSCC coincides with acquisition of front-to-rear polarity and increased organisation of 3D spheroid cultures. In addition, we show that type VII collagen positively regulates the abundance of markers implicated in cellular polarity, namely ELMO2, PAR3, E-cadherin, B-catenin, ITGA6 and Ln332.


Assuntos
Carcinoma de Células Escamosas/metabolismo , Polaridade Celular , Colágeno Tipo VII/fisiologia , Epidermólise Bolhosa Distrófica/metabolismo , Transportadores de Ânions Orgânicos Sódio-Independentes/metabolismo , Neoplasias Cutâneas/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Antígenos CD , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Caderinas/genética , Caderinas/metabolismo , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patologia , Moléculas de Adesão Celular/genética , Moléculas de Adesão Celular/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Técnicas de Cocultura , Proteínas do Citoesqueleto/genética , Proteínas do Citoesqueleto/metabolismo , Epidermólise Bolhosa Distrófica/genética , Epidermólise Bolhosa Distrófica/patologia , Regulação Neoplásica da Expressão Gênica , Humanos , Integrina alfa6/genética , Integrina alfa6/metabolismo , Queratinócitos , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Transplante de Neoplasias , Transportadores de Ânions Orgânicos Sódio-Independentes/genética , Regiões Promotoras Genéticas , Transporte Proteico , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/patologia , Membro 1B3 da Família de Transportadores de Ânion Orgânico Carreador de Soluto , Transcrição Gênica , Células Tumorais Cultivadas , beta Catenina/genética , beta Catenina/metabolismo , Calinina
12.
Genome Biol ; 14(11): R124, 2013 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-24200198

RESUMO

ChIP-seq is an established manually-performed method for identifying DNA-protein interactions genome-wide. Here, we describe a protocol for automated high-throughput (AHT) ChIP-seq. To demonstrate the quality of data obtained using AHT-ChIP-seq, we applied it to five proteins in mouse livers using a single 96-well plate, demonstrating an extremely high degree of qualitative and quantitative reproducibility among biological and technical replicates. We estimated the optimum and minimum recommended cell numbers required to perform AHT-ChIP-seq by running an additional plate using HepG2 and MCF7 cells. With this protocol, commercially available robotics can perform four hundred experiments in five days.


Assuntos
Imunoprecipitação da Cromatina/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Robótica/métodos , Animais , Imunoprecipitação da Cromatina/instrumentação , Células Hep G2 , Sequenciamento de Nucleotídeos em Larga Escala/instrumentação , Humanos , Fígado/metabolismo , Células MCF-7 , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Reprodutibilidade dos Testes , Robótica/instrumentação , Análise de Sequência de DNA
13.
Methods Mol Biol ; 731: 467-70, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21516429

RESUMO

Maintenance of a mitotically inactive feeder layer which is able to provide extracellular matrix and growth factors can be critical in establishing and maintaining primary tumor cells. How feeder cells are handled and processed is crucial for providing trouble-free support for primary tumor cells and spontaneously immortalized lines.


Assuntos
Técnicas de Cocultura/métodos , Células 3T3 , Animais , Sobrevivência Celular , Camundongos , Mitose
14.
J Cell Sci ; 123(Pt 18): 3047-51, 2010 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-20736315

RESUMO

To ensure equal replication of the genome in every eukaryotic cell cycle, replication origins fire only once each S phase and do not fire after passive replication. Failure in these controls can lead to local amplification, contributing to genome instability and the development of cancer. To identify features of replication origins important for such amplification, we have investigated origin firing and local genome amplification in the presence of excess helicase loaders Cdc18 and Cdt1 in fission yeast. We find that S phase controls are attenuated and coordination of origin firing is lost, resulting in local amplification. Specific origins are necessary for amplification but act only within a permissive chromosomal context. Origins associated with amplification are highly AT-rich, fire efficiently and early during mitotic S phase, and are located in large intergenic regions. We propose that these features predispose replication origins to re-fire within a single S phase, or to remain active after passive replication.


Assuntos
Replicação do DNA , Origem de Replicação , Schizosaccharomyces/genética , Fase S , Schizosaccharomyces/citologia , Schizosaccharomyces/metabolismo , Proteínas de Schizosaccharomyces pombe/genética , Proteínas de Schizosaccharomyces pombe/metabolismo
15.
Nucleic Acids Res ; 38(19): 6555-66, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20547592

RESUMO

Multiple KH-domain proteins, collectively known as vigilins, are evolutionarily highly conserved proteins that are present in eukaryotic organisms from yeast to metazoa. Proposed roles for vigilins include chromosome segregation, messenger RNA (mRNA) metabolism, translation and tRNA transport. As a step toward understanding its biological function, we have identified the fission yeast vigilin, designated Vgl1, and have investigated its role in cellular response to environmental stress. Unlike its counterpart in Saccharomyces cerevisiae, we found no indication that Vgl1 is required for the maintenance of cell ploidy in Schizosaccharomyces pombe. Instead, Vgl1 is required for cell survival under thermal stress, and vgl1Δ mutants lose their viability more rapidly than wild-type cells when incubated at high temperature. As for Scp160 in S. cerevisiae, Vgl1 bound polysomes accumulated at endoplasmic reticulum (ER) but in a microtubule-independent manner. Under thermal stress, Vgl1 is rapidly relocalized from the ER to cytoplasmic foci that are distinct from P-bodies but contain stress granule markers such as poly(A)-binding protein and components of the translation initiation factor eIF3. Together, these observations demonstrated in S. pombe the presence of RNA granules with similar composition as mammalian stress granules and identified Vgl1 as a novel component that required for cell survival under thermal stress.


Assuntos
Grânulos Citoplasmáticos/química , Proteínas de Schizosaccharomyces pombe/fisiologia , Retículo Endoplasmático/química , Expressão Gênica , Temperatura Alta , Microtúbulos/fisiologia , Mutação , Poliploidia , Estrutura Terciária de Proteína , Proteínas de Ligação a RNA/análise , Proteínas de Saccharomyces cerevisiae/análise , Schizosaccharomyces/genética , Schizosaccharomyces/metabolismo , Proteínas de Schizosaccharomyces pombe/química , Proteínas de Schizosaccharomyces pombe/genética , Estresse Fisiológico
16.
Nat Struct Mol Biol ; 16(12): 1286-93, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19915592

RESUMO

Histone variant H2A.Z has a conserved role in genome stability, although it remains unclear how this is mediated. Here we demonstrate that the fission yeast Swr1 ATPase inserts H2A.Z (Pht1) into chromatin and Kat5 acetyltransferase (Mst1) acetylates it. Deletion or an unacetylatable mutation of Pht1 leads to genome instability, primarily caused by chromosome entanglement and breakage at anaphase. This leads to the loss of telomere-proximal markers, though telomere protection and repeat length are unaffected by the absence of Pht1. Strikingly, the chromosome entanglement in pht1Delta anaphase cells can be rescued by forcing chromosome condensation before anaphase onset. We show that the condensin complex, required for the maintenance of anaphase chromosome condensation, prematurely dissociates from chromatin in the absence of Pht1. This and other findings suggest an important role for H2A.Z in the architecture of anaphase chromosomes.


Assuntos
Cromatina/metabolismo , Cromossomos Fúngicos/metabolismo , Proteínas Fúngicas/metabolismo , Instabilidade Genômica , Histonas/metabolismo , Proteínas de Schizosaccharomyces pombe/metabolismo , Schizosaccharomyces/fisiologia , Acetilação , Acetiltransferases/metabolismo , Adenosina Trifosfatases/metabolismo , Quebra Cromossômica , Deleção de Genes , Histonas/genética , Modelos Biológicos , Proteínas de Schizosaccharomyces pombe/genética
18.
Rapid Commun Mass Spectrom ; 22(22): 3501-9, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18853393

RESUMO

Amphibian peptides which inhibit the formation of nitric oxide by neuronal nitric oxide synthase (nNOS) do so by binding to the protein cofactor, Ca2+calmodulin (Ca2+CaM). Complex formation between active peptides and Ca2+CaM has been demonstrated by negative ion electrospray ionisation mass spectrometry using an aqueous ammonium acetate buffer system. In all cases studied, the assemblies are formed with a 1:1:4 calmodulin/peptide/Ca2+ stoichiometry. In contrast, the complex involving the 20-residue binding domain of the plasma Ca2+ pump C20W (LRRGQILWFRGLNRIQTQIK-OH) with CaM has been shown by previous two-dimensional nuclear magnetic resonance (2D NMR) studies to involve complexation of the C-terminal end of CaM. Under identical conditions to those used for the amphibian peptide study, the ESI complex between C20W and CaM shows specific 1:1:2 stoichiometry. Since complex formation with the studied amphibian peptides requires Ca2+CaM to contain its full complement of four Ca2+ ions, this indicates that the amphibian peptides require both ends of the CaM to effect complex formation. Charge-state analysis and an H/D exchange experiment (with caerin 1.8) suggest that complexation involves Ca2+CaM undergoing a conformational change to a more compact structure.


Assuntos
Proteínas de Anfíbios/química , Anuros/metabolismo , Cálcio/química , Calmodulina/química , Óxido Nítrico Sintase Tipo I/química , Peptídeos/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Proteínas de Anfíbios/metabolismo , Animais , Sítios de Ligação , Cálcio/metabolismo , Calmodulina/metabolismo , Óxido Nítrico Sintase Tipo I/metabolismo , Peptídeos/metabolismo , Ligação Proteica
19.
J Biol Chem ; 283(32): 22063-75, 2008 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-18502752

RESUMO

int-6 is one of the frequent integration sites for mouse mammary tumor viruses. Although its product is the e-subunit of translation initiation factor eIF3, other evidence indicates that it interacts with proteasomes or other proteins to regulate protein stability. Here we report that the fission yeast int6(+) is required for overcoming stress imposed by histidine starvation, using the drug 3-aminotriazole (3AT). Microarray and complementary Northern studies using wild-type, int6Delta or gcn2Delta mutants indicate that 3AT-treated wild-type yeast induces core environmental stress response (CESR) genes in addition to typical general amino acid control (GAAC) genes whose transcription depends on the eIF2 kinase, Gcn2. In agreement with this, Sty1 MAPK and its target transcription factor Atf1, which signal the CESR, are required for overcoming 3AT-induced starvation. We find that Int6 is required for maintaining the basal level of Atf1 and for rapid transcriptional activation of the CESR on 3AT-insult. Pulse labeling experiments indicate that int6Delta significantly slows down de novo protein synthesis. Moreover, Atf1 protein half-life was reduced in int6Delta cells. These effects would account for the compromised Atf1 activity on 3AT-induced stress. Thus, the robust protein synthesis promoted by intact eIF3 appears to be a part of the requisites for sound Sty1 MAPK-dependent signaling governed by the activity of the Atf1 transcription factor.


Assuntos
Fator de Iniciação 3 em Eucariotos/metabolismo , Regulação Fúngica da Expressão Gênica , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Biossíntese de Proteínas , Proteínas/metabolismo , Proteínas de Schizosaccharomyces pombe/metabolismo , Schizosaccharomyces/metabolismo , Aminoácidos/metabolismo , Amitrol (Herbicida)/farmacologia , Fator de Iniciação 3 em Eucariotos/genética , Perfilação da Expressão Gênica , Histidina/metabolismo , Família Multigênica , Mutação , Proteínas/genética , Schizosaccharomyces/efeitos dos fármacos , Transdução de Sinais
20.
Eukaryot Cell ; 7(3): 493-508, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18223116

RESUMO

The fission yeast Schizosaccharomyces pombe responds to the deprivation of iron by inducing the expression of the php4+ gene, which encodes a negative regulatory subunit of the heteromeric CCAAT-binding factor. Once formed, the Php2/3/4/5 transcription complex is required to inactivate a subset of genes encoding iron-using proteins. Here, we used a pan-S. pombe microarray to study the transcriptional response to iron starvation and identified 86 genes that exhibit php4+-dependent changes on a genome-wide scale. One of these genes encodes the iron-responsive transcriptional repressor Fep1, whose mRNA levels were decreased after treatment with the permeant iron chelator 2,2'-dipyridyl. In addition, several genes encoding the components of iron-dependent biochemical pathways, including the tricarboxylic acid cycle, mitochondrial respiration, amino acid biosynthesis, and oxidative stress defense, were downregulated in response to iron deficiency. Furthermore, Php4 repressed transcription when brought to a promoter using a yeast DNA-binding domain, and iron deprivation was required for this repression. On the other hand, Php4 was constitutively active when glutathione levels were depleted within the cell. Based on these and previous results, we propose that iron-dependent inactivation of Php4 is regulated at two distinct levels: first, at the transcriptional level by the iron-responsive GATA factor Fep1 and second, at the posttranscriptional level by a mechanism yet to be identified, which inhibits Php4-mediated repressive function when iron is abundant.


Assuntos
Fator de Ligação a CCAAT/metabolismo , Regulação Fúngica da Expressão Gênica , Ferro/metabolismo , Proteínas de Schizosaccharomyces pombe/metabolismo , Schizosaccharomyces/metabolismo , Vias Biossintéticas , Regulação para Baixo , Transporte de Elétrons , Fatores de Transcrição GATA/genética , Perfilação da Expressão Gênica , Quelantes de Ferro/metabolismo , Mitocôndrias/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Schizosaccharomyces/genética , Proteínas de Schizosaccharomyces pombe/genética
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