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1.
ArXiv ; 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38699161

RESUMO

Computational methods for assessing the likely impacts of mutations, known as variant effect predictors (VEPs), are widely used in the assessment and interpretation of human genetic variation, as well as in other applications like protein engineering. Many different VEPs have been released to date, and there is tremendous variability in their underlying algorithms and outputs, and in the ways in which the methodologies and predictions are shared. This leads to considerable challenges for end users in knowing which VEPs to use and how to use them. Here, to address these issues, we provide guidelines and recommendations for the release of novel VEPs. Emphasising open-source availability, transparent methodologies, clear variant effect score interpretations, standardised scales, accessible predictions, and rigorous training data disclosure, we aim to improve the usability and interpretability of VEPs, and promote their integration into analysis and evaluation pipelines. We also provide a large, categorised list of currently available VEPs, aiming to facilitate the discovery and encourage the usage of novel methods within the scientific community.

2.
BMJ Open ; 14(5): e085237, 2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38760043

RESUMO

INTRODUCTION: Around 2000 children are born in the UK per year with a neurodevelopmental genetic syndrome with significantly increased morbidity and mortality. Often little is known about expected growth and phenotypes in these children. Parents have responded by setting up social media groups to generate data themselves. Given the significant clinical evidence gaps, this research will attempt to identify growth patterns, developmental profiles and phenotypes, providing data on long-term medical and educational outcomes. This will guide clinicians when to investigate, monitor or treat symptoms and when to search for additional or alternative diagnoses. METHODS AND ANALYSIS: This is an observational, multicentre cohort study recruiting between March 2023 and February 2026. Children aged 6 months up to 16 years with a pathogenic or likely pathogenic variant in a specified gene will be eligible. Children will be identified through the National Health Service and via self-recruitment. Parents or carers will complete a questionnaire at baseline and again 1 year after recruitment. The named clinician (in most cases a clinical geneticist) will complete a clinical proforma which will provide data from their most recent clinical assessment. Qualitative interviews will be undertaken with a subset of parents partway through the study. Growth and developmental milestone curves will be generated through the DECIPHER website (https://deciphergenomics.org) where 5 or more children have the same genetic syndrome (at least 10 groups expected). ETHICS AND DISSEMINATION: The results will be presented at national and international conferences concerning the care of children with genetic syndromes. Results will also be submitted for peer review and publication.


Assuntos
Doenças Raras , Humanos , Doenças Raras/genética , Doenças Raras/terapia , Criança , Pré-Escolar , Reino Unido , Lactente , Adolescente , Projetos de Pesquisa , Feminino , Masculino , Estudos Observacionais como Assunto , Transtornos do Neurodesenvolvimento/genética , Estudos de Coortes , Estudos Multicêntricos como Assunto , Doenças Genéticas Inatas/terapia , Melhoria de Qualidade , Pais
4.
Genet Med ; 26(2): 101029, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37982373

RESUMO

PURPOSE: The terminology used for gene-disease curation and variant annotation to describe inheritance, allelic requirement, and both sequence and functional consequences of a variant is currently not standardized. There is considerable discrepancy in the literature and across clinical variant reporting in the derivation and application of terms. Here, we standardize the terminology for the characterization of disease-gene relationships to facilitate harmonized global curation and to support variant classification within the ACMG/AMP framework. METHODS: Terminology for inheritance, allelic requirement, and both structural and functional consequences of a variant used by Gene Curation Coalition members and partner organizations was collated and reviewed. Harmonized terminology with definitions and use examples was created, reviewed, and validated. RESULTS: We present a standardized terminology to describe gene-disease relationships, and to support variant annotation. We demonstrate application of the terminology for classification of variation in the ACMG SF 2.0 genes recommended for reporting of secondary findings. Consensus terms were agreed and formalized in both Sequence Ontology (SO) and Human Phenotype Ontology (HPO) ontologies. Gene Curation Coalition member groups intend to use or map to these terms in their respective resources. CONCLUSION: The terminology standardization presented here will improve harmonization, facilitate the pooling of curation datasets across international curation efforts and, in turn, improve consistency in variant classification and genetic test interpretation.


Assuntos
Testes Genéticos , Variação Genética , Humanos , Alelos , Bases de Dados Genéticas
5.
Annu Rev Genomics Hum Genet ; 24: 151-176, 2023 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-37285546

RESUMO

DECIPHER (Database of Genomic Variation and Phenotype in Humans Using Ensembl Resources) shares candidate diagnostic variants and phenotypic data from patients with genetic disorders to facilitate research and improve the diagnosis, management, and therapy of rare diseases. The platform sits at the boundary between genomic research and the clinical community. DECIPHER aims to ensure that the most up-to-date data are made rapidly available within its interpretation interfaces to improve clinical care. Newly integrated cardiac case-control data that provide evidence of gene-disease associations and inform variant interpretation exemplify this mission. New research resources are presented in a format optimized for use by a broad range of professionals supporting the delivery of genomic medicine. The interfaces within DECIPHER integrate and contextualize variant and phenotypic data, helping to determine a robust clinico-molecular diagnosis for rare-disease patients, which combines both variant classification and clinical fit. DECIPHER supports discovery research, connecting individuals within the rare-disease community to pursue hypothesis-driven research.


Assuntos
Genômica , Genômica/métodos , Humanos , Doenças Raras/genética , Alelos , Guias de Prática Clínica como Assunto , Variações do Número de Cópias de DNA , Bases de Dados Genéticas
6.
medRxiv ; 2023 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-37066232

RESUMO

PURPOSE: The terminology used for gene-disease curation and variant annotation to describe inheritance, allelic requirement, and both sequence and functional consequences of a variant is currently not standardized. There is considerable discrepancy in the literature and across clinical variant reporting in the derivation and application of terms. Here we standardize the terminology for the characterization of disease-gene relationships to facilitate harmonized global curation, and to support variant classification within the ACMG/AMP framework. METHODS: Terminology for inheritance, allelic requirement, and both structural and functional consequences of a variant used by Gene Curation Coalition (GenCC) members and partner organizations was collated and reviewed. Harmonized terminology with definitions and use examples was created, reviewed, and validated. RESULTS: We present a standardized terminology to describe gene-disease relationships, and to support variant annotation. We demonstrate application of the terminology for classification of variation in the ACMG SF 2.0 genes recommended for reporting of secondary findings. Consensus terms were agreed and formalized in both sequence ontology (SO) and human phenotype ontology (HPO) ontologies. GenCC member groups intend to use or map to these terms in their respective resources. CONCLUSION: The terminology standardization presented here will improve harmonization, facilitate the pooling of curation datasets across international curation efforts and, in turn, improve consistency in variant classification and genetic test interpretation.

7.
N Engl J Med ; 388(17): 1559-1571, 2023 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-37043637

RESUMO

BACKGROUND: Pediatric disorders include a range of highly penetrant, genetically heterogeneous conditions amenable to genomewide diagnostic approaches. Finding a molecular diagnosis is challenging but can have profound lifelong benefits. METHODS: We conducted a large-scale sequencing study involving more than 13,500 families with probands with severe, probably monogenic, difficult-to-diagnose developmental disorders from 24 regional genetics services in the United Kingdom and Ireland. Standardized phenotypic data were collected, and exome sequencing and microarray analyses were performed to investigate novel genetic causes. We developed an iterative variant analysis pipeline and reported candidate variants to clinical teams for validation and diagnostic interpretation to inform communication with families. Multiple regression analyses were performed to evaluate factors affecting the probability of diagnosis. RESULTS: A total of 13,449 probands were included in the analyses. On average, we reported 1.0 candidate variant per parent-offspring trio and 2.5 variants per singleton proband. Using clinical and computational approaches to variant classification, we made a diagnosis in approximately 41% of probands (5502 of 13,449). Of 3599 probands in trios who received a diagnosis by clinical assertion, approximately 76% had a pathogenic de novo variant. Another 22% of probands (2997 of 13,449) had variants of uncertain significance in genes that were strongly linked to monogenic developmental disorders. Recruitment in a parent-offspring trio had the largest effect on the probability of diagnosis (odds ratio, 4.70; 95% confidence interval [CI], 4.16 to 5.31). Probands were less likely to receive a diagnosis if they were born extremely prematurely (i.e., 22 to 27 weeks' gestation; odds ratio, 0.39; 95% CI, 0.22 to 0.68), had in utero exposure to antiepileptic medications (odds ratio, 0.44; 95% CI, 0.29 to 0.67), had mothers with diabetes (odds ratio, 0.52; 95% CI, 0.41 to 0.67), or were of African ancestry (odds ratio, 0.51; 95% CI, 0.31 to 0.78). CONCLUSIONS: Among probands with severe, probably monogenic, difficult-to-diagnose developmental disorders, multimodal analysis of genomewide data had good diagnostic power, even after previous attempts at diagnosis. (Funded by the Health Innovation Challenge Fund and Wellcome Sanger Institute.).


Assuntos
Genômica , Doenças Raras , Criança , Humanos , Exoma , Irlanda/epidemiologia , Reino Unido/epidemiologia , Doenças Raras/diagnóstico , Doenças Raras/epidemiologia , Doenças Raras/genética , Análise de Sequência com Séries de Oligonucleotídeos , Estudos de Associação Genética , Transtornos do Neurodesenvolvimento/diagnóstico , Transtornos do Neurodesenvolvimento/genética , Anormalidades Congênitas/diagnóstico , Anormalidades Congênitas/genética , Transtornos do Crescimento/diagnóstico , Transtornos do Crescimento/genética , Fácies , Transtornos do Comportamento Infantil/diagnóstico , Transtornos do Comportamento Infantil/genética , Doenças Genéticas Inatas/diagnóstico , Doenças Genéticas Inatas/genética
8.
Hum Mutat ; 43(6): 682-697, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35143074

RESUMO

DECIPHER (https://www.deciphergenomics.org) is a free web platform for sharing anonymized phenotype-linked variant data from rare disease patients. Its dynamic interpretation interfaces contextualize genomic and phenotypic data to enable more informed variant interpretation, incorporating international standards for variant classification. DECIPHER supports almost all types of germline and mosaic variation in the nuclear and mitochondrial genome: sequence variants, short tandem repeats, copy-number variants, and large structural variants. Patient phenotypes are deposited using Human Phenotype Ontology (HPO) terms, supplemented by quantitative data, which is aggregated to derive gene-specific phenotypic summaries. It hosts data from >250 projects from ~40 countries, openly sharing >40,000 patient records containing >51,000 variants and >172,000 phenotype terms. The rich phenotype-linked variant data in DECIPHER drives rare disease research and diagnosis by enabling patient matching within DECIPHER and with other resources, and has been cited in >2,600 publications. In this study, we describe the types of data deposited to DECIPHER, the variant interpretation tools, and patient matching interfaces which make DECIPHER an invaluable rare disease resource.


Assuntos
Bases de Dados Genéticas , Doenças Raras , Genômica , Humanos , Fenótipo , Doenças Raras/diagnóstico , Doenças Raras/genética , Software
9.
Eur J Hum Genet ; 26(12): 1721-1731, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30069064

RESUMO

The Global Alliance for Genomics and Health (GA4GH) proposes a data access policy model-"registered access"-to increase and improve access to data requiring an agreement to basic terms and conditions, such as the use of DNA sequence and health data in research. A registered access policy would enable a range of categories of users to gain access, starting with researchers and clinical care professionals. It would also facilitate general use and reuse of data but within the bounds of consent restrictions and other ethical obligations. In piloting registered access with the Scientific Demonstration data sharing projects of GA4GH, we provide additional ethics, policy and technical guidance to facilitate the implementation of this access model in an international setting.


Assuntos
Acesso à Informação , Genética Médica/normas , Genômica/normas , Disseminação de Informação , Genética Médica/ética , Genética Médica/legislação & jurisprudência , Genômica/ética , Genômica/legislação & jurisprudência , Humanos , Licenciamento , Guias de Prática Clínica como Assunto
10.
Curr Protoc Hum Genet ; 95: 9.31.1-9.31.15, 2017 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-29044468

RESUMO

In well over half of the individuals with rare disease who undergo clinical or research next-generation sequencing, the responsible gene cannot be determined. Some reasons for this relatively low yield include unappreciated phenotypic heterogeneity; locus heterogeneity; somatic and germline mosaicism; variants of uncertain functional significance; technically inaccessible areas of the genome; incorrect mode of inheritance investigated; and inadequate communication between clinicians and basic scientists with knowledge of particular genes, proteins, or biological systems. To facilitate such communication and improve the search for patients or model organisms with similar phenotypes and variants in specific candidate genes, we have developed the Matchmaker Exchange (MME). MME was created to establish a federated network connecting databases of genomic and phenotypic data using a common application programming interface (API). To date, seven databases can exchange data using the API (GeneMatcher, PhenomeCentral, DECIPHER, MyGene2, matchbox, Australian Genomics Health Alliance Patient Archive, and Monarch Initiative; the latter included for model organism matching). This article guides usage of the MME for rare disease gene discovery. © 2017 by John Wiley & Sons, Inc.


Assuntos
Bases de Dados Genéticas , Estudos de Associação Genética/métodos , Predisposição Genética para Doença , Doenças Raras/genética , Animais , Biologia Computacional/métodos , Genômica/métodos , Humanos , Software , Navegador
11.
EMBO J ; 35(19): 2068-2086, 2016 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-27497297

RESUMO

Upon DNA damage, cyclin-dependent kinases (CDKs) are typically inhibited to block cell division. In many organisms, however, it has been found that CDK activity is required for DNA repair, especially for homology-dependent repair (HR), resulting in the conundrum how mitotic arrest and repair can be reconciled. Here, we show that Arabidopsis thaliana solves this dilemma by a division of labor strategy. We identify the plant-specific B1-type CDKs (CDKB1s) and the class of B1-type cyclins (CYCB1s) as major regulators of HR in plants. We find that RADIATION SENSITIVE 51 (RAD51), a core mediator of HR, is a substrate of CDKB1-CYCB1 complexes. Conversely, mutants in CDKB1 and CYCB1 fail to recruit RAD51 to damaged DNA CYCB1;1 is specifically activated after DNA damage and we show that this activation is directly controlled by SUPPRESSOR OF GAMMA RESPONSE 1 (SOG1), a transcription factor that acts similarly to p53 in animals. Thus, while the major mitotic cell-cycle activity is blocked after DNA damage, CDKB1-CYCB1 complexes are specifically activated to mediate HR.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Ciclina B/metabolismo , Quinases Ciclina-Dependentes/metabolismo , Reparo de DNA por Recombinação , Proteínas de Arabidopsis/genética , Ciclina B/genética , Quinases Ciclina-Dependentes/genética , Rad51 Recombinase/metabolismo , Fatores de Transcrição/metabolismo
12.
Mol Syst Biol ; 11(1): 776, 2015 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-25600997

RESUMO

Clock-regulated pathways coordinate the response of many developmental processes to changes in photoperiod and temperature. We model two of the best-understood clock output pathways in Arabidopsis, which control key regulators of flowering and elongation growth. In flowering, the model predicted regulatory links from the clock to cycling DOF factor 1 (CDF1) and flavin-binding, KELCH repeat, F-box 1 (FKF1) transcription. Physical interaction data support these links, which create threefold feed-forward motifs from two clock components to the floral regulator FT. In hypocotyl growth, the model described clock-regulated transcription of phytochrome-interacting factor 4 and 5 (PIF4, PIF5), interacting with post-translational regulation of PIF proteins by phytochrome B (phyB) and other light-activated pathways. The model predicted bimodal and end-of-day PIF activity profiles that are observed across hundreds of PIF-regulated target genes. In the response to temperature, warmth-enhanced PIF4 activity explained the observed hypocotyl growth dynamics but additional, temperature-dependent regulators were implicated in the flowering response. Integrating these two pathways with the clock model highlights the molecular mechanisms that coordinate plant development across changing conditions.


Assuntos
Arabidopsis/genética , Ritmo Circadiano , Flores/fisiologia , Hipocótilo/crescimento & desenvolvimento , Fotoperíodo , RNA de Plantas/isolamento & purificação , Temperatura , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Relógios Circadianos/genética , Bases de Dados Genéticas , Regulação da Expressão Gênica de Plantas , Luz , Fitocromo B/genética , Fitocromo B/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA de Plantas/genética , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Transdução de Sinais , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
13.
Nat Commun ; 5: 4848, 2014 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-25258215

RESUMO

In Arabidopsis, the seedling hypocotyl has emerged as an exemplar model system to study light and temperature control of cell expansion. Light sensitivity of this organ is epitomized in the fluence rate response where suppression of hypocotyl elongation increases incrementally with light intensity. This finely calibrated response is controlled by the photoreceptor, phytochrome B, through the deactivation and proteolytic destruction of phytochrome-interacting factors (PIFs). Here we show that this classical light response is strictly temperature dependent: a shift in temperature induces a dramatic reversal of response from inhibition to promotion of hypocotyl elongation by light. Applying an integrated experimental and mathematical modelling approach, we show how light and temperature coaction in the circuitry drives a molecular switch in PIF activity and control of cell expansion. This work provides a paradigm to understand the importance of signal convergence in evoking different or non-intuitive alterations in molecular signalling.


Assuntos
Arabidopsis/crescimento & desenvolvimento , Arabidopsis/efeitos da radiação , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Hipocótilo/crescimento & desenvolvimento , Hipocótilo/metabolismo , Hipocótilo/efeitos da radiação , Luz , Fitocromo B/genética , Fitocromo B/metabolismo , Temperatura
14.
Plant Cell ; 25(11): 4391-404, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24254125

RESUMO

Cold acclimation has been shown to be attenuated by the degradation of the INDUCER OF CBF EXPRESSION1 protein by the E3 ubiquitin ligase HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENES1 (HOS1). However, recent work has suggested that HOS1 may have a wider range of roles in plants than previously appreciated. Here, we show that hos1 mutants are affected in circadian clock function, exhibiting a long-period phenotype in a wide range of temperature and light environments. We demonstrate that hos1 mutants accumulate polyadenylated mRNA in the nucleus and that the circadian defect in hos1 is shared by multiple mutants with aberrant mRNA export, but not in a mutant attenuated in nucleo-cytoplasmic transport of microRNAs. As revealed by RNA sequencing, hos1 exhibits gross changes to the transcriptome with genes in multiple functional categories being affected. In addition, we show that hos1 and other previously described mutants with altered mRNA export affect cold signaling in a similar manner. Our data support a model in which altered mRNA export is important for the manifestation of hos1 circadian clock defects and suggest that HOS1 may indirectly affect cold signaling through disruption of the circadian clock.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/fisiologia , Relógios Circadianos/fisiologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas Nucleares/metabolismo , Transporte de RNA , RNA Mensageiro/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Núcleo Celular/genética , Núcleo Celular/metabolismo , Temperatura Baixa , Citoplasma/genética , Citoplasma/metabolismo , RNA Helicases DEAD-box/genética , RNA Helicases DEAD-box/metabolismo , Regulação da Expressão Gênica de Plantas , Peptídeos e Proteínas de Sinalização Intracelular/genética , Mutação , Proteínas Nucleares/genética , Plantas Geneticamente Modificadas , Poliadenilação , Regiões Promotoras Genéticas , Proteínas R-SNARE/genética , Proteínas R-SNARE/metabolismo , Transdução de Sinais/genética
15.
Biostatistics ; 14(4): 792-806, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23743206

RESUMO

Estimation of the period length of time-course data from cyclical biological processes, such as those driven by the circadian pacemaker, is crucial for inferring the properties of the biological clock found in many living organisms. We propose a methodology for period estimation based on spectrum resampling (SR) techniques. Simulation studies show that SR is superior and more robust to non-sinusoidal and noisy cycles than a currently used routine based on Fourier approximations. In addition, a simple fit to the oscillations using linear least squares is available, together with a non-parametric test for detecting changes in period length which allows for period estimates with different variances, as frequently encountered in practice. The proposed methods are motivated by and applied to various data examples from chronobiology.


Assuntos
Relógios Biológicos/fisiologia , Ritmo Circadiano/fisiologia , Interpretação Estatística de Dados , Análise de Regressão , Animais , Arabidopsis/crescimento & desenvolvimento , Cromoterapia/métodos , Neoplasias Colorretais/tratamento farmacológico , Simulação por Computador , Humanos , Pneumopatias/tratamento farmacológico , Camundongos , Proteínas Circadianas Period/uso terapêutico , Temperatura Cutânea/efeitos dos fármacos
16.
Mol Syst Biol ; 9: 650, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23511208

RESUMO

Circadian clocks exhibit 'temperature compensation', meaning that they show only small changes in period over a broad temperature range. Several clock genes have been implicated in the temperature-dependent control of period in Arabidopsis. We show that blue light is essential for this, suggesting that the effects of light and temperature interact or converge upon common targets in the circadian clock. Our data demonstrate that two cryptochrome photoreceptors differentially control circadian period and sustain rhythmicity across the physiological temperature range. In order to test the hypothesis that the targets of light regulation are sufficient to mediate temperature compensation, we constructed a temperature-compensated clock model by adding passive temperature effects into only the light-sensitive processes in the model. Remarkably, this model was not only capable of full temperature compensation and consistent with mRNA profiles across a temperature range, but also predicted the temperature-dependent change in the level of LATE ELONGATED HYPOCOTYL, a key clock protein. Our analysis provides a systems-level understanding of period control in the plant circadian oscillator.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/fisiologia , Relógios Circadianos , Modelos Biológicos , Proteínas de Arabidopsis/genética , Criptocromos/genética , Criptocromos/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica de Plantas , Luz , Modelos Teóricos , Mutação , Plantas Geneticamente Modificadas , Transdução de Sinais , Temperatura , Termodinâmica , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
17.
Plant Signal Behav ; 6(4): 471-6, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21364315

RESUMO

Accurate development of the gynoecium, the female reproductive organ, is necessary to achieve efficient fertilization. In Arabidopsis, the correct patterning of the apical-basal axis of the gynoecium requires the establishment of a morphogenic gradient of auxin. This allows the production of specialized tissues, whose roles consist of attracting pollen, allowing pollen tube growth and protecting the ovules within the ovaries. Mutations in the bHLH transcription factor SPATULA (SPT) are known to impair the development of the apical tissues of the gynoecium. Here, we show that the spt phenotype is rescued by the removal of phytochrome B, and discuss how light signaling may control flower development.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Flores/crescimento & desenvolvimento , Flores/metabolismo , Fitocromo B/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Flores/genética , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Fitocromo B/genética , Plantas Geneticamente Modificadas/genética
18.
Plant J ; 65(3): 441-52, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21265897

RESUMO

The ability to withstand environmental temperature variation is essential for plant survival. Former studies in Arabidopsis revealed that light signalling pathways had a potentially unique role in shielding plant growth and development from seasonal and daily fluctuations in temperature. In this paper we describe the molecular circuitry through which the light receptors cry1 and phyB buffer the impact of warm ambient temperatures. We show that the light signalling component HFR1 acts to minimise the potentially devastating effects of elevated temperature on plant physiology. Light is known to stabilise levels of HFR1 protein by suppressing proteasome-mediated destruction of HFR1. We demonstrate that light-dependent accumulation and activity of HFR1 are highly temperature dependent. The increased potency of HFR1 at warmer temperatures provides an important restraint on PIF4 that drives elongation growth. We show that warm ambient temperatures promote the accumulation of phosphorylated PIF4. However, repression of PIF4 activity by phyB and cry1 (via HFR1) is critical for controlling growth and maintaining physiology as temperatures rise. Loss of this light-mediated restraint has severe consequences for adult plants which have greatly reduced biomass.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Criptocromos/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteínas Nucleares/metabolismo , Fitocromo B/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Biomassa , Criptocromos/genética , Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Luz , Proteínas Nucleares/genética , Fenótipo , Fosforilação , Fitocromo B/genética , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/metabolismo , Transdução de Sinais/efeitos da radiação , Temperatura
19.
Cell ; 139(6): 1170-9, 2009 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-20005809

RESUMO

Photoperiod sensors allow physiological adaptation to the changing seasons. The prevalent hypothesis is that day length perception is mediated through coupling of an endogenous rhythm with an external light signal. Sufficient molecular data are available to test this quantitatively in plants, though not yet in mammals. In Arabidopsis, the clock-regulated genes CONSTANS (CO) and FLAVIN, KELCH, F-BOX (FKF1) and their light-sensitive proteins are thought to form an external coincidence sensor. Here, we model the integration of light and timing information by CO, its target gene FLOWERING LOCUS T (FT), and the circadian clock. Among other predictions, our models show that FKF1 activates FT. We demonstrate experimentally that this effect is independent of the known activation of CO by FKF1, thus we locate a major, novel controller of photoperiodism. External coincidence is part of a complex photoperiod sensor: modeling makes this complexity explicit and may thus contribute to crop improvement.


Assuntos
Arabidopsis/fisiologia , Flores/fisiologia , Regulação da Expressão Gênica de Plantas , Modelos Genéticos , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Relógios Biológicos , Proteínas de Ligação a DNA/genética , Redes Reguladoras de Genes , Fotoperíodo , Fatores de Transcrição/genética
20.
Plant Cell Environ ; 31(5): 667-78, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18266901

RESUMO

Since the discovery of the physical interaction between phytochrome B and the basic helix-loop-helix (bHLH) transcription factor (TF) PIF3 a decade ago, plant phytochrome-signalling research has largely focused on understanding the mechanisms through which phytochromes and members of this bHLH family signal. This concerted effort has revealed how phytochrome and bHLH TF control gene expression and plant growth, and has assigned precise roles to a number of genes in the PIF3-like bHLH TF clade. This work has focused largely on cell autonomous signalling events; however, to synchronize plant growth and developmental events at the tissue and organ level, temporal and spatial signal integration is crucial. This review brings together current knowledge of phytochrome signalling through phytochrome-interacting factors (PIFs)/phytochrome-interacting factor-like (PILs), and it evaluates the current evidence for cross-tissue signal integration.


Assuntos
Fitocromo/metabolismo , Plantas/metabolismo , Transdução de Sinais , Fotossíntese
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