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1.
J Allied Health ; 53(2): e77-e91, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38834346

RESUMO

BACKGROUND: Data management (DM) systems represent an opportunity for innovation in education and data-driven decision-making (DDDM) in allied health education. Understanding clinical education (CE) DM systems in entry-level physical therapy (PT) education programs could provide valuable insight into structure and operation and may represent opportunities to address CE challenges. The purpose of this study is to describe how PT programs are using CE DM systems to inform recommendations for CE DM and support knowledge sharing and DDDM. SUBJECTS: CE faculty and administrators were recruited from entry-level PT education programs to participate in a cross-sectional survey. METHODS: The authors designed a novel survey which included demographics and use of CE DM systems. Descriptive statistics and content analysis of narrative data were used to examine responses. RESULTS: The survey was distributed to 220 academic PT programs in June 2021 with 111 respondents (50% response rate). Respondents use multiple systems to complete CE tasks (e.g., placement process, on-boarding, agreement tracking, as a CE site database). Forty-three percent (n=47) use one system, 76% (n=35) of those use the same Software as a Service vendor. Eighty-six percent (n=96) are satisfied with their current CE DM system. Respondents enter data related to CE site information, CE environment, length of the CE experience, and accreditation-required clinical instructor information. Ninety-four percent (n=93) and 70% (n=70) extract data to make decisions about the placement process and curriculum, respectively. CONCLUSION: While variability across CE DM systems presents a challenge, survey respondents indicated common practices related to functionality, data entry, and extraction. Clinical education DM systems house critical data to address challenges in CE. Strategies to improve accessibility and use of this data to support DDDM should be explored.


Assuntos
Gerenciamento de Dados , Humanos , Estudos Transversais , Especialidade de Fisioterapia/educação , Inquéritos e Questionários , Fisioterapeutas/educação , Masculino , Feminino
2.
J Mol Biol ; 436(7): 168318, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-37863247

RESUMO

Within the SET domain superfamily of lysine methyltransferases, there is a well-conserved subfamily, frequently referred to as the Set3 SET domain subfamily, which contain noncanonical SET domains carrying divergent amino acid sequences. These proteins are implicated in diverse biological processes including stress responses, cell differentiation, and development, and their disruption is linked to diseases including cancer and neurodevelopmental disorders. Interestingly, biochemical and structural analysis indicates that they do not possess catalytic methyltransferase activity. At the molecular level, Set3 SET domain proteins appear to play critical roles in the regulation of gene expression, particularly repression and heterochromatin maintenance, and in some cases, via scaffolding other histone modifying activities at chromatin. Here, we explore the common and unique functions among Set3 SET domain subfamily proteins and analyze what is known about the specific contribution of the conserved SET domain to functional roles of these proteins, as well as propose areas of investigation to improve understanding of this important, noncanonical subfamily of proteins.


Assuntos
Histona-Lisina N-Metiltransferase , Domínios PR-SET , Sequência de Aminoácidos , Cromatina/química , Cromatina/metabolismo , Histona-Lisina N-Metiltransferase/química , Histona-Lisina N-Metiltransferase/genética , Histona-Lisina N-Metiltransferase/metabolismo , Humanos , Animais
3.
Sci Adv ; 9(46): eadi5921, 2023 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-37976356

RESUMO

Aberrant activation of Ras/Raf/mitogen-activated protein kinase (MAPK) signaling is frequently linked to metastatic prostate cancer (PCa); therefore, the characterization of modulators of this pathway is critical for defining therapeutic vulnerabilities for metastatic PCa. The lysine methyltransferase SET and MYND domain 3 (SMYD3) methylates MAPK kinase kinase 2 (MAP3K2) in some cancers, causing enhanced activation of MAPK signaling. In PCa, SMYD3 is frequently overexpressed and associated with disease severity; however, its molecular function in promoting tumorigenesis has not been defined. We demonstrate that SMYD3 critically regulates tumor-associated phenotypes via its methyltransferase activity in PCa cells and mouse xenograft models. SMYD3-dependent methylation of MAP3K2 promotes epithelial-mesenchymal transition associated behaviors by altering the abundance of the intermediate filament vimentin. Furthermore, activation of the SMYD3-MAP3K2 signaling axis supports a positive feedback loop continually promoting high levels of SMYD3. Our data provide insight into signaling pathways involved in metastatic PCa and enhance understanding of mechanistic functions for SMYD3 to reveal potential therapeutic opportunities for PCa.


Assuntos
Neoplasias da Próstata , Masculino , Camundongos , Animais , Humanos , Neoplasias da Próstata/genética , Transdução de Sinais , Carcinogênese/genética , Transformação Celular Neoplásica/genética , Proteínas Quinases Ativadas por Mitógeno/genética , Metiltransferases/genética , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , MAP Quinase Quinase Quinase 2/genética , MAP Quinase Quinase Quinase 2/metabolismo , Histona-Lisina N-Metiltransferase/genética , Histona-Lisina N-Metiltransferase/metabolismo
4.
Mol Biol Cell ; 34(1): ar6, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-36416860

RESUMO

Set1 is an H3K4 methyltransferase that comprises the catalytic subunit of the COMPASS complex and has been implicated in transcription, DNA repair, cell cycle control, and numerous other genomic functions. Set1 also promotes proper telomere maintenance, as cells lacking Set1 have short telomeres and disrupted subtelomeric gene repression; however, the precise role for Set1 in these processes has not been fully defined. In this study, we have tested mutants of Set1 and the COMPASS complex that differentially alter H3K4 methylation status, and we have attempted to separate catalytic and noncatalytic functions of Set1. Our data reveal that Set1-dependent subtelomeric gene repression relies on its catalytic activity toward H3K4, whereas telomere length is regulated by Set1 catalytic activity but likely independent of the H3K4 substrate. Furthermore, we uncover a role for Set1 in calibrating the abundance of critical telomere maintenance proteins, including components of the telomerase holoenzyme and members of the telomere capping CST (Cdc13-Stn1-Ten1) complex, through both transcriptional and posttranscriptional pathways. Altogether, our data provide new insights into the H3K4 methylation-dependent and -independent roles for Set1 in telomere maintenance in yeast and shed light on possible roles for Set1-related methyltransferases in other systems.


Assuntos
Proteínas de Saccharomyces cerevisiae , Metilação , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Histona-Lisina N-Metiltransferase/genética , Histona-Lisina N-Metiltransferase/metabolismo , Histonas/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Telômero/metabolismo , Proteínas de Ligação a Telômeros/metabolismo
5.
STAR Protoc ; 2(4): 100945, 2021 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-34816128

RESUMO

Protein regulation by post-translational modifications and protein-protein interactions is critical to controlling molecular pathways. Here, we describe an immunoaffinity purification approach in Saccharomyces cerevisiae. The protocol uses an endogenously-expressed epitope-tagged protein and can be applied to the identification of post-translational modifications or protein binding partners. The lysine methyltransferase Set5 is used as an example here to purify phosphorylated Set5 and identify phosphosites; however, this approach can be applied to a diverse set of proteins in yeast. For complete details on the use and execution of this protocol, please refer to Jaiswal et al. (2020).


Assuntos
Imunoprecipitação/métodos , Mapeamento de Interação de Proteínas/métodos , Processamento de Proteína Pós-Traducional , Proteínas de Saccharomyces cerevisiae , Centrifugação , Eletroforese em Gel de Poliacrilamida , Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/análise , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/isolamento & purificação
6.
Life Sci Alliance ; 4(12)2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34625508

RESUMO

The yeast chromatin protein Set4 is a member of the Set3-subfamily of SET domain proteins which play critical roles in the regulation of gene expression in diverse developmental and environmental contexts. We previously reported that Set4 promotes survival during oxidative stress and regulates expression of stress response genes via stress-dependent chromatin localization. In this study, global gene expression analysis and investigation of histone modification status identified a role for Set4 in maintaining gene repressive mechanisms within yeast subtelomeres under both normal and stress conditions. We show that Set4 works in a partially overlapping pathway to the SIR complex and the histone deacetylase Rpd3 to maintain proper levels of histone acetylation and expression of stress response genes encoded in subtelomeres. This role for Set4 is particularly critical for cells under hypoxic conditions, where the loss of Set4 decreases cell fitness and cell wall integrity. These findings uncover a new regulator of subtelomeric chromatin that is key to stress defense pathways and demonstrate a function for Set4 in regulating repressive, heterochromatin-like environments.


Assuntos
Proteínas Cromossômicas não Histona/metabolismo , Regulação Fúngica da Expressão Gênica , Histona Desacetilases/metabolismo , Estresse Oxidativo/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/enzimologia , Saccharomyces cerevisiae/genética , Telômero/metabolismo , Acetilação , Cromatina/metabolismo , Proteínas Cromossômicas não Histona/genética , Inativação Gênica , Código das Histonas/genética , Histonas/metabolismo , Microrganismos Geneticamente Modificados/genética , Proteínas de Saccharomyces cerevisiae/genética , Transdução de Sinais/genética , Telômero/genética
7.
Appetite ; 166: 105435, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34144095

RESUMO

Early adolescence is a critical time for health behavior development because agency increases during the transition from childhood to adolescence. This qualitative study sought to identify how early adolescent participants described food-related agency. One-on-one interviews were conducted with 30 early adolescents (10-13 years). Data analysis was guided by Bandura's three modes of agency: personal, proxy, and collective. Results suggest participants' food behaviors were informed by a growing knowledge about nutrition, household food rules, and school food environments. Participants described different modes of agency in four areas - grocery shopping, cooking, consumption decisions, and nutrition information seeking - with varying degrees of agency in each area. Understanding how each of the three modes operate and the interplay between them can information future research aimed at improving the nutrition behaviors of early adolescents.


Assuntos
Alimentos , Comportamentos Relacionados com a Saúde , Adolescente , Criança , Culinária , Humanos , Estado Nutricional , Pesquisa Qualitativa
8.
Appetite ; 158: 105012, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33132192

RESUMO

Early adolescence (ages 10-14) encompasses a critical transition period in which food and nutrition decisions are shifting in important ways. Food routines are food-based activities that repeat across days, weeks, seasons, or lives. Examining routines can provide insight into how individuals are influenced in food choices. The objective of this study was to describe current influences on and experiences with food routines during early adolescence. In-depth interviews, using a photo-elicitation approach, were conducted with 30 participants (16 females; 14 males) in the United States. Participants took photos that were then used during the interview to describe food-related decisions and influences. Interviews were audio recorded and transcribed verbatim. Analysis was guided by a grounded theory approach to identify emergent themes related to routines and resulted in the development of a conceptual model for early adolescent food routines. Participants identified a wide range of routines and three main themes emerged: family, settings, and meals/foods consumed. Some had highly established routines throughout the week, while others described routines only for certain meals or days. Several participants described increased control or the ability to modify routines around some eating episodes such as snacks, lunches, and weekend breakfasts. Findings revealed how participants viewed eating routines and provided information about food-and nutrition-related behaviors that can inform future research and practice. Early adolescents appear to have complex food routines influenced by structures and different amounts of control.


Assuntos
Comportamento Alimentar , Preferências Alimentares , Adolescente , Criança , Feminino , Humanos , Masculino , Refeições , Estado Nutricional , Pesquisa Qualitativa , Lanches , Estados Unidos
9.
Curr Protein Pept Sci ; 21(7): 690-698, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31642774

RESUMO

The post-translational modifications (PTM) of proteins are crucial for cells to survive under diverse environmental conditions and to respond to stimuli. PTMs are known to govern a broad array of cellular processes including signal transduction and chromatin regulation. The PTM lysine methylation has been extensively studied within the context of chromatin and the epigenetic regulation of the genome. However, it has also emerged as a critical regulator of non-histone proteins important for signal transduction pathways. While the number of known non-histone protein methylation events is increasing, the molecular functions of many of these modifications are not yet known. Proteomic studies of the model system Saccharomyces cerevisiae suggest lysine methylation may regulate a diversity of pathways including transcription, RNA processing, translation, and signal transduction cascades. However, there has still been relatively little investigation of lysine methylation as a broad cellular regulator beyond chromatin and transcription. Here, we outline our current state of understanding of non-histone protein methylation in yeast and propose ways in which the yeast system can be leveraged to develop a much more complete picture of molecular mechanisms through which lysine methylation regulates cellular functions.


Assuntos
Regulação Fúngica da Expressão Gênica , Histona-Lisina N-Metiltransferase/metabolismo , Lisina/metabolismo , Processamento de Proteína Pós-Traducional , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/enzimologia , Cromatina/química , Cromatina/enzimologia , Histona-Lisina N-Metiltransferase/classificação , Histona-Lisina N-Metiltransferase/genética , Histonas/genética , Histonas/metabolismo , Metilação , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/classificação , Proteínas de Saccharomyces cerevisiae/genética , Transdução de Sinais
10.
Mol Cell Biol ; 40(2)2020 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-31685550

RESUMO

SMYD lysine methyltransferases target histones and nonhistone proteins for methylation and are critical regulators of muscle development and implicated in neoplastic transformation. They are characterized by a split catalytic SET domain and an intervening MYND zinc finger domain, as well as an extended C-terminal domain. Saccharomyces cerevisiae contains two SMYD proteins, Set5 and Set6, which share structural elements with the mammalian SMYD enzymes. Set5 is a histone H4 lysine 5, 8, and 12 methyltransferase, implicated in the regulation of stress responses and genome stability. While the SMYD proteins have diverse roles in cells, there are many gaps in our understanding of how these enzymes are regulated. Here, we performed mutational analysis of Set5, combined with phosphoproteomics, to identify regulatory mechanisms for its enzymatic activity and subcellular localization. Our results indicate that the MYND domain promotes Set5 chromatin association in cells and is required for its role in repressing subtelomeric genes. Phosphoproteomics revealed extensive phosphorylation of Set5, and phosphomimetic mutations enhance Set5 catalytic activity but diminish its ability to interact with chromatin in cells. These studies uncover multiple regions within Set5 that regulate its localization and activity and highlight potential avenues for understanding mechanisms controlling the diverse roles of SMYD enzymes.


Assuntos
Metiltransferases/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Domínio Catalítico , Cromatina/metabolismo , Histonas/metabolismo , Lisina/metabolismo , Domínios MYND , Metilação , Metiltransferases/análise , Fosforilação , Saccharomyces cerevisiae/citologia , Proteínas de Saccharomyces cerevisiae/análise
11.
Cells ; 8(2)2019 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-30823596

RESUMO

Telomeres, the nucleoprotein structures at the ends of eukaryotic chromosomes, play an integral role in protecting linear DNA from degradation. Dysregulation of telomeres can result in genomic instability and has been implicated in increased rates of cellular senescence and many diseases, including cancer. The integrity of telomeres is maintained by a coordinated network of proteins and RNAs, such as the telomerase holoenzyme and protective proteins that prevent the recognition of the telomere ends as a DNA double-strand breaks. The structure of chromatin at telomeres and within adjacent subtelomeres has been implicated in telomere maintenance pathways in model systems and humans. Specific post-translational modifications of histones, including methylation, acetylation, and ubiquitination, have been shown to be necessary for maintaining a chromatin environment that promotes telomere integrity. Here we review the current knowledge regarding the role of histone modifications in maintaining telomeric and subtelomeric chromatin, discuss the implications of histone modification marks as they relate to human disease, and highlight key areas for future research.


Assuntos
Histonas/metabolismo , Processamento de Proteína Pós-Traducional , Telômero/metabolismo , Animais , Cromatina/metabolismo , Doença , Humanos , Modelos Biológicos
12.
Bio Protoc ; 9(2)2019 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-30800719

RESUMO

In the presence of oxidative stress, cellular defense systems that can detoxify reactive oxygen species are activated through multiple signaling cascades and transcriptional reprogramming. The budding yeast Saccharomyces cerevisiae has served as an excellent model for genetically-identifying factors important for the response to oxidative stress. Here, we describe two assays for testing yeast gene deletion strains or strains overexpressing a gene of interest for viability following oxidative stress induced by hydrogen peroxide treatment. These include a plate-based spot assay for visualizing cell growth and a quantitative colony counting assay. As stress response assays can be highly variable depending on cell growth conditions, these protocols have been optimized for obtaining highly-reproducible results between experiments. We demonstrate the use of these protocols for genetic tests of a putative chromatin regulator implicated in regulating the transcriptional response to oxidative stress.

13.
Curr Genet ; 65(3): 643-648, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30523388

RESUMO

Chromatin dynamics are central to the regulation of gene expression and genome stability, particularly in the presence of environmental signals or stresses that prompt rapid reprogramming of the genome to promote survival or differentiation. While numerous chromatin regulators have been implicated in modulating cellular responses to stress, gaps in our mechanistic understanding of chromatin-based changes during stress suggest that additional proteins are likely critical to these responses and the molecular details underlying their activities are unclear in many cases. We recently identified a role for the relatively uncharacterized SET domain protein Set4 in promoting cell survival during oxidative stress in Saccharomyces cerevisiae. Set4 is a member of the Set3 subfamily of SET domain proteins which are defined by the presence of a PHD finger and divergent SET domain sequences. Here, we integrate our new observations on the function of Set4 with known roles for other related family members, including yeast Set3, fly UpSET and mammalian proteins MLL5 and SETD5. We discuss outstanding questions regarding the molecular mechanisms by which these proteins control gene expression and their potential contributions to cellular responses to environmental stress.


Assuntos
Proteínas Cromossômicas não Histona/metabolismo , Regulação Fúngica da Expressão Gênica , Estresse Oxidativo , Domínios PR-SET , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Cromatina/genética , Cromatina/metabolismo , Proteínas Cromossômicas não Histona/genética , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética
14.
J Biol Chem ; 293(37): 14429-14443, 2018 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-30082318

RESUMO

The Set4 protein in the yeast Saccharomyces cerevisiae contains both a PHD finger and a SET domain, a common signature of chromatin-associated proteins, and shares sequence homology with the yeast protein Set3, the fly protein UpSET, and the human protein mixed-lineage leukemia 5 (MLL5). However, the biological role for Set4 and its potential function in chromatin regulation has not been well defined. Here, we analyzed yeast cell phenotypes associated with loss of Set4 or its overexpression, which revealed that Set4 protects against oxidative stress induced by hydrogen peroxide. Gene expression analysis indicated that Set4 promotes the activation of stress response genes in the presence of oxidative insults. Using ChIP analysis and other biochemical assays, we also found that Set4 interacts with chromatin and directly localizes to stress response genes upon oxidative stress. However, recombinant Set4 did not show detectable methyltransferase activity on histones. Our findings also suggest that Set4 abundance in the cell is balanced under normal and stress conditions to promote survival. Overall, these results suggest a model in which Set4 is a stress-responsive, chromatin-associated protein that activates gene expression programs required for cellular protection against oxidative stress. This work advances our understanding of mechanisms that protect cells during oxidative stress and further defines the role of the Set3-Set4 subfamily of SET domain-containing proteins in controlling gene expression in response to adverse environmental conditions.


Assuntos
Cromatina/metabolismo , Proteínas Cromossômicas não Histona/fisiologia , Regulação Fúngica da Expressão Gênica/fisiologia , Genes Fúngicos , Estresse Oxidativo , Proteínas de Saccharomyces cerevisiae/fisiologia , Saccharomyces cerevisiae/metabolismo , Estresse Fisiológico/genética , Proteínas Cromossômicas não Histona/genética , Metilação de DNA , Ergosterol/biossíntese , Histona Desacetilases/metabolismo , Histona Desacetilases/fisiologia , Histonas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética
15.
G3 (Bethesda) ; 7(12): 3971-3982, 2017 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-29066473

RESUMO

The conserved yeast histone methyltransferase Set1 targets H3 lysine 4 (H3K4) for mono, di, and trimethylation and is linked to active transcription due to the euchromatic distribution of these methyl marks and the recruitment of Set1 during transcription. However, loss of Set1 results in increased expression of multiple classes of genes, including genes adjacent to telomeres and middle sporulation genes, which are repressed under normal growth conditions because they function in meiotic progression and spore formation. The mechanisms underlying Set1-mediated gene repression are varied, and still unclear in some cases, although repression has been linked to both direct and indirect action of Set1, associated with noncoding transcription, and is often dependent on the H3K4me2 mark. We show that Set1, and particularly the H3K4me2 mark, are implicated in repression of a subset of middle sporulation genes during vegetative growth. In the absence of Set1, there is loss of the DNA-binding transcriptional regulator Sum1 and the associated histone deacetylase Hst1 from chromatin in a locus-specific manner. This is linked to increased H4K5ac at these loci and aberrant middle gene expression. These data indicate that, in addition to DNA sequence, histone modification status also contributes to proper localization of Sum1 Our results also show that the role for Set1 in middle gene expression control diverges as cells receive signals to undergo meiosis. Overall, this work dissects an unexplored role for Set1 in gene-specific repression, and provides important insights into a new mechanism associated with the control of gene expression linked to meiotic differentiation.


Assuntos
Metilação de DNA/genética , Histona-Lisina N-Metiltransferase/genética , Proteínas Nucleares/genética , Proteínas Repressoras/genética , Proteínas de Saccharomyces cerevisiae/genética , Sirtuína 2/genética , Esporos Fúngicos/genética , Cromatina/genética , Proteínas de Ligação a DNA/genética , Regulação Fúngica da Expressão Gênica , Histona Metiltransferases , Meiose/genética , Complexos Multiproteicos/genética , Saccharomyces cerevisiae/genética
16.
J Vis Exp ; (130)2017 12 29.
Artigo em Inglês | MEDLINE | ID: mdl-29364237

RESUMO

Histone post-translational modifications (PTMs), such as acetylation, methylation and phosphorylation, are dynamically regulated by a series of enzymes that add or remove these marks in response to signals received by the cell. These PTMS are key contributors to the regulation of processes such as gene expression control and DNA repair. Chromatin immunoprecipitation (chIP) has been an instrumental approach for dissecting the abundance and localization of many histone PTMs throughout the genome in response to diverse perturbations to the cell. Here, a versatile method for performing chIP of post-translationally modified histones from the budding yeast Saccharomyces cerevisiae (S. cerevisiae) is described. This method relies on crosslinking of proteins and DNA using formaldehyde treatment of yeast cultures, generation of yeast lysates by bead beating, solubilization of chromatin fragments by micrococcal nuclease, and immunoprecipitation of histone-DNA complexes. DNA associated with the histone mark of interest is purified and subjected to quantitative PCR analysis to evaluate its enrichment at multiple loci throughout the genome. Representative experiments probing the localization of the histone marks H3K4me2 and H4K16ac in wildtype and mutant yeast are discussed to demonstrate data analysis and interpretation. This method is suitable for a variety of histone PTMs and can be performed with different mutant strains or in the presence of diverse environmental stresses, making it an excellent tool for investigating changes in chromatin dynamics under different conditions.


Assuntos
Imunoprecipitação da Cromatina/métodos , Histonas/metabolismo , Saccharomyces cerevisiae/metabolismo , Histonas/genética , Saccharomyces cerevisiae/genética
17.
J Mol Biol ; 429(13): 1946-1957, 2017 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-27769718

RESUMO

When yeast cells are challenged by a fluctuating environment, signaling networks activate differentiation programs that promote their individual or collective survival. These programs include the initiation of meiotic sporulation, the formation of filamentous growth structures, and the activation of programmed cell death pathways. The establishment and maintenance of these distinct cell fates are driven by massive gene expression programs that promote the necessary changes in morphology and physiology. While these genomic reprogramming events depend on a specialized network of transcription factors, a diverse set of chromatin regulators, including histone-modifying enzymes, chromatin remodelers, and histone variants, also play essential roles. Here, we review the broad functions of histone modifications in initiating cell fate transitions, with particular focus on their contribution to the control of expression of key genes required for the differentiation programs and chromatin reorganization that accompanies these cell fates.


Assuntos
Adaptação Fisiológica , Regulação Fúngica da Expressão Gênica , Código das Histonas , Histonas/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/fisiologia
18.
Epigenetics ; 12(2): 93-104, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27911222

RESUMO

Genes adjacent to telomeres are subject to transcriptional repression mediated by an integrated set of chromatin modifying and remodeling factors. The telomeres of Saccharomyces cerevisiae have served as a model for dissecting the function of diverse chromatin proteins in gene silencing, and their study has revealed overlapping roles for many chromatin proteins in either promoting or antagonizing gene repression. The H3K4 methyltransferase Set1, which is commonly linked to transcriptional activation, has been implicated in telomere silencing. Set5 is an H4 K5, K8, and K12 methyltransferase that functions with Set1 to promote repression at telomeres. Here, we analyzed the combined role for Set1 and Set5 in gene expression control at native yeast telomeres. Our data reveal that Set1 and Set5 promote a Sir protein-independent mechanism of repression that may primarily rely on regulation of H4K5ac and H4K8ac at telomeric regions. Furthermore, cells lacking both Set1 and Set5 have highly correlated transcriptomes to mutants in telomere maintenance pathways and display defects in telomere stability, linking their roles in silencing to protection of telomeres. Our data therefore provide insight into and clarify potential mechanisms by which Set1 contributes to telomere silencing and shed light on the function of Set5 at telomeres.


Assuntos
Inativação Gênica , Histona-Lisina N-Metiltransferase/metabolismo , Metiltransferases/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Homeostase do Telômero , Histona-Lisina N-Metiltransferase/genética , Histonas/metabolismo , Metilação , Metiltransferases/genética , Processamento de Proteína Pós-Traducional , Saccharomyces cerevisiae/enzimologia , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Transcriptoma
19.
Epigenetics ; 9(4): 513-22, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24442241

RESUMO

A complex interplay between multiple chromatin modifiers is critical for cells to regulate chromatin structure and accessibility during essential DNA-templated processes such as transcription. However, the coordinated activities of these chromatin modifiers in the regulation of gene expression are not fully understood. We previously determined that the budding yeast histone H4 methyltransferase Set5 functions together with Set1, the H3K4 methyltransferase, in specific cellular contexts. Here, we sought to understand the relationship between these evolutionarily conserved enzymes in the regulation of gene expression. We generated a comprehensive genetic interaction map of the functionally uncharacterized Set5 methyltransferase and expanded the existing genetic interactome of the global chromatin modifier Set1, revealing functional overlap of the two enzymes in chromatin-related networks, such as transcription. Furthermore, gene expression profiling via RNA-Seq revealed an unexpected synergistic role of Set1 and Set5 in repressing transcription of Ty transposable elements and genes located in subtelomeric regions. This study uncovers novel pathways in which the methyltransferase Set5 participates and, more importantly, reveals a partnership between Set1 and Set5 in transcriptional repression near repetitive DNA elements in budding yeast. Together, our results define a new functional relationship between histone H3 and H4 methyltransferases, whose combined activity may be implicated in preserving genomic integrity.


Assuntos
Histona-Lisina N-Metiltransferase/metabolismo , Retroelementos , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Telômero/metabolismo , Cromatina/metabolismo , Expressão Gênica , Histona-Lisina N-Metiltransferase/genética , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Telômero/genética
20.
Nat Protoc ; 9(1): 37-50, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24309976

RESUMO

We present a protocol for using the triple malignant brain tumor domains of L3MBTL1 (3xMBT), which bind to mono- and di-methylated lysine with minimal sequence specificity, in order to enrich for such methylated lysine from cell lysates. Cells in culture are grown with amino acids containing light or heavy stable isotopic labels. Methylated proteins are enriched by incubating cell lysates with 3xMBT, or with the binding-null D355N mutant as a negative control. Quantitative liquid chromatography and tandem mass spectrometry (LC-MS/MS) are then used to identify proteins that are specifically enriched by 3xMBT pull-down. The addition of a third isotopic label allows the comparison of protein lysine methylation between different biological conditions. Unlike most approaches, our strategy does not require a prior hypothesis of candidate methylated proteins, and it recognizes a wider range of methylated proteins than any available method using antibodies. Cells are prepared by growing in isotopic labeling medium for about 7 d; the process of enriching methylated proteins takes 3 d and analysis by LC-MS/MS takes another 1-2 d.


Assuntos
Lisina/metabolismo , Proteínas/isolamento & purificação , Proteômica/métodos , Cromatografia Líquida/métodos , Escherichia coli/metabolismo , Metilação , Proteínas/química , Proteínas/metabolismo , Espectrometria de Massas em Tandem/métodos
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