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1.
PLoS Biol ; 20(10): e3001839, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36269765

RESUMO

Hsp70 interactions are critical for cellular viability and the response to stress. Previous attempts to characterize Hsp70 interactions have been limited by their transient nature and the inability of current technologies to distinguish direct versus bridged interactions. We report the novel use of cross-linking mass spectrometry (XL-MS) to comprehensively characterize the Saccharomyces cerevisiae (budding yeast) Hsp70 protein interactome. Using this approach, we have gained fundamental new insights into Hsp70 function, including definitive evidence of Hsp70 self-association as well as multipoint interaction with its client proteins. In addition to identifying a novel set of direct Hsp70 interactors that can be used to probe chaperone function in cells, we have also identified a suite of posttranslational modification (PTM)-associated Hsp70 interactions. The majority of these PTMs have not been previously reported and appear to be critical in the regulation of client protein function. These data indicate that one of the mechanisms by which PTMs contribute to protein function is by facilitating interaction with chaperones. Taken together, we propose that XL-MS analysis of chaperone complexes may be used as a unique way to identify biologically important PTMs on client proteins.


Assuntos
Proteínas de Choque Térmico HSP70 , Proteínas de Saccharomyces cerevisiae , Humanos , Ligação Proteica , Proteínas de Choque Térmico HSP70/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Processamento de Proteína Pós-Traducional , Chaperonas Moleculares/metabolismo , Proteínas de Choque Térmico HSP90/metabolismo
2.
Mol Biol Evol ; 40(10)2023 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-37789509

RESUMO

The transition from oviparity to viviparity has occurred independently over 150 times across vertebrates, presenting one of the most compelling cases of phenotypic convergence. However, whether the repeated, independent evolution of viviparity is driven by redeployment of similar genetic mechanisms and whether these leave a common signature in genomic divergence remains largely unknown. Although recent investigations into the evolution of viviparity have demonstrated striking similarity among the genes and molecular pathways involved across disparate vertebrate groups, quantitative tests for genome-wide convergent have provided ambivalent answers. Here, we investigate the potential role of molecular convergence during independent transitions to viviparity across an order of ray-finned freshwater fish (Cyprinodontiformes). We assembled de novo genomes and utilized publicly available genomes of viviparous and oviparous species to test for molecular convergence across both coding and noncoding regions. We found no evidence for an excess of molecular convergence in amino acid substitutions and in rates of sequence divergence, implying independent genetic changes are associated with these transitions. However, both statistical power and biological confounds could constrain our ability to detect significant correlated evolution. We therefore identified candidate genes with potential signatures of molecular convergence in viviparous Cyprinodontiformes lineages. Motif enrichment and gene ontology analyses suggest transcriptional changes associated with early morphogenesis, brain development, and immunity occurred alongside the evolution of viviparity. Overall, however, our findings indicate that independent transitions to viviparity in these fish are not strongly associated with an excess of molecular convergence, but a few genes show convincing evidence of convergent evolution.


Assuntos
Ciprinodontiformes , Lagartos , Animais , Filogenia , Viviparidade não Mamífera/genética , Lagartos/genética , Genômica , Ciprinodontiformes/genética , Evolução Biológica
3.
Heredity (Edinb) ; 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38858547

RESUMO

Understanding the phylogeographic history of a group and identifying the factors contributing to speciation is an important challenge in evolutionary biology. The Goodeinae are a group of live-bearing fishes endemic to Mexico. Here, we develop genomic resources for species within the Goodeinae and use phylogenomic approaches to characterise their evolutionary history. We sequenced, assembled and annotated the genomes of four Goodeinae species, including Ataeniobius toweri, the only matrotrophic live-bearing fish without a trophotaenia in the group. We estimated timings of species divergence and examined the extent and timing of introgression between the species to assess if this may have occurred during an early radiation, or in more recent episodes of secondary contact. We used branch-site models to detect genome-wide positive selection across Goodeinae, and we specifically asked whether this differs in A. toweri, where loss of placental viviparity has recently occurred. We found evidence of gene flow between geographically isolated species, suggesting vicariant speciation was supplemented by limited post-speciation gene flow, and gene flow may explain previous uncertainties about Goodeid phylogeny. Genes under positive selection in the group are likely to be associated with the switch to live-bearing. Overall, our studies suggest that both volcanism-driven vicariance and changes in reproductive mode influenced radiation in the Goodeinae.

4.
Mol Ecol ; 32(6): 1515-1529, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-35560992

RESUMO

Potato cyst nematodes (PCNs), an umbrella term used for two species, Globodera pallida and G. rostochiensis, belong worldwide to the most harmful pathogens of potato. Pathotype-specific host plant resistances are essential for PCN control. However, the poor delineation of G. pallida pathotypes has hampered the efficient use of available host plant resistances. Long-read sequencing technology allowed us to generate a new reference genome of G. pallida population D383 and, as compared to the current reference, the new genome assembly is 42 times less fragmented. For comparison of diversification patterns of six effector families between G. pallida and G. rostochiensis, an additional reference genome was generated for an outgroup, the beet cyst nematode Heterodera schachtii (IRS population). Large evolutionary contrasts in effector family topologies were observed. While VAPs (venom allergen-like proteins) diversified before the split between the three cyst nematode species, the families GLAND5 and GLAND13 only expanded in PCNs after their separation from the genus Heterodera. Although DNA motifs in the promoter regions thought to be involved in the orchestration of effector expression ("DOG boxes") were present in all three cyst nematode species, their presence is not a necessity for dorsal gland-produced effectors. Notably, DOG box dosage was only loosely correlated with the expression level of individual effector variants. Comparison of the G. pallida genome with those of two other cyst nematodes underlined the fundamental differences in evolutionary history between effector families. Resequencing of PCN populations with different virulence characteristics will allow for the linking of these characteristics to the composition of the effector repertoire as well as for the mapping of PCN diversification patterns resulting from extreme anthropogenic range expansion.


Assuntos
Genômica , Nematoides , Animais , Análise de Sequência de DNA , Antioxidantes , Regiões Promotoras Genéticas
5.
PLoS Biol ; 18(11): e3000917, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33180788

RESUMO

The transition from mitosis into the first gap phase of the cell cycle in budding yeast is controlled by the Mitotic Exit Network (MEN). The network interprets spatiotemporal cues about the progression of mitosis and ensures that release of Cdc14 phosphatase occurs only after completion of key mitotic events. The MEN has been studied intensively; however, a unified understanding of how localisation and protein activity function together as a system is lacking. In this paper, we present a compartmental, logical model of the MEN that is capable of representing spatial aspects of regulation in parallel to control of enzymatic activity. We show that our model is capable of correctly predicting the phenotype of the majority of mutants we tested, including mutants that cause proteins to mislocalise. We use a continuous time implementation of the model to demonstrate that Cdc14 Early Anaphase Release (FEAR) ensures robust timing of anaphase, and we verify our findings in living cells. Furthermore, we show that our model can represent measured cell-cell variation in Spindle Position Checkpoint (SPoC) mutants. This work suggests a general approach to incorporate spatial effects into logical models. We anticipate that the model itself will be an important resource to experimental researchers, providing a rigorous platform to test hypotheses about regulation of mitotic exit.


Assuntos
Ciclo Celular/genética , Pontos de Checagem da Fase M do Ciclo Celular/fisiologia , Ciclo Celular/fisiologia , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/fisiologia , Divisão do Núcleo Celular/fisiologia , Pontos de Checagem da Fase M do Ciclo Celular/genética , Mitose/fisiologia , Fosforilação , Proteínas Tirosina Fosfatases/genética , Proteínas Tirosina Fosfatases/metabolismo , Proteínas Tirosina Fosfatases/fisiologia , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/fisiologia , Saccharomycetales/genética , Saccharomycetales/metabolismo , Fuso Acromático/fisiologia
6.
PLoS Genet ; 16(8): e1008990, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32810142

RESUMO

The kinetochore, a multi-protein complex assembled on centromeres, is essential to segregate chromosomes during cell division. Deficiencies in kinetochore function can lead to chromosomal instability and aneuploidy-a hallmark of cancer cells. Kinetochore function is controlled by recruitment of regulatory proteins, many of which have been documented, however their function often remains uncharacterized and many are yet to be identified. To identify candidates of kinetochore regulation we used a proteome-wide protein association strategy in budding yeast and detected many proteins that are involved in post-translational modifications such as kinases, phosphatases and histone modifiers. We focused on the Polo-like kinase, Cdc5, and interrogated which cellular components were sensitive to constitutive Cdc5 localization. The kinetochore is particularly sensitive to constitutive Cdc5 kinase activity. Targeting Cdc5 to different kinetochore subcomplexes produced diverse phenotypes, consistent with multiple distinct functions at the kinetochore. We show that targeting Cdc5 to the inner kinetochore, the constitutive centromere-associated network (CCAN), increases the levels of centromeric RNA via an SPT4 dependent mechanism.


Assuntos
Proteínas de Ciclo Celular/genética , Centrômero/genética , Proteínas Nucleares/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas/genética , Proteínas de Saccharomyces cerevisiae/genética , Fatores de Elongação da Transcrição/genética , Anáfase/genética , Proteínas Cromossômicas não Histona/genética , Segregação de Cromossomos/genética , Histonas/genética , Humanos , Cinetocoros/metabolismo , Mitose/genética , Fenótipo , Fosforilação/genética , RNA/genética , Saccharomyces cerevisiae/genética , Quinase 1 Polo-Like
7.
BMC Bioinformatics ; 23(1): 60, 2022 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-35123390

RESUMO

BACKGROUND: Colony growth on solid media is a simple and effective measure for high-throughput genomic experiments such as yeast two-hybrid, synthetic dosage lethality and Synthetic Physical Interaction screens. The development of robotic pinning tools has facilitated the experimental design of these assays, and different imaging software can be used to automatically measure colony sizes on plates. However, comparison to control plates and statistical data analysis is often laborious and pinning issues or plate specific growth effects can lead to the detection of false-positive growth defects. RESULTS: We have developed ScreenGarden, a shinyR application, to enable easy, quick and robust data analysis of plate-based high throughput assays. The code allows comparisons of different formats of data and different sized arrays of colonies. A comparison of ScreenGarden with previous analysis tools shows that it performs, at least, equivalently. The software can be run either via a website or offline via the RStudio program; the code is available and can be modified by expert uses to customise the analysis. CONCLUSIONS: ScreenGarden provides a simple, fast and effective tool to analyse colony growth data from genomic experiments.


Assuntos
Genômica , Software , Meios de Cultura , Ensaios de Triagem em Larga Escala , Saccharomyces cerevisiae
8.
Immunology ; 166(2): 249-264, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35318648

RESUMO

The recent success of monoclonal antibody checkpoint inhibitor therapies that enhance the ability of CD8+ T cells to detect cancer-related antigenic peptides has refocused the need to fully understand the repertoire of peptides being presented to the immune system. Whilst the peptide ligandome presented by cell surface human leucocyte antigen class I (HLA-I) molecules on cancer cells has been studied extensively, the ligandome of extracellular vesicles (EVs) remains poorly defined. Here, we report the HLA-I ligandome of both the cell surface and EVs from eight breast cancer cell lines (MCF7, MDA-MB-231, MDA-MB-361, MDA-MB-415, MDA-MB-453, HCC 1806, HCC 1395, and HCC 1954), and additionally the melanoma cell line ESTDAB-056 and the multiple myeloma line RPMI 8226. Utilizing HLA-I immunoisolation and mass spectrometry, we detected a total of 6574 peptides from the cell surface and 2461 peptides from the EVs of the cell lines studied. Within the EV HLA-I ligandome, we identified 150 peptides derived from tumour associated antigenic proteins, of which 19 peptides have been shown to elicit T-cell responses in previous studies. Our data thus show the prevalence of clinically relevant tumour-associated antigenic peptides in the HLA-I ligandome presented on EV.


Assuntos
Carcinoma Hepatocelular , Vesículas Extracelulares , Neoplasias Hepáticas , Antígenos de Neoplasias , Linfócitos T CD8-Positivos , Carcinoma Hepatocelular/metabolismo , Linhagem Celular , Antígenos de Histocompatibilidade Classe I/metabolismo , Humanos , Ligantes , Neoplasias Hepáticas/metabolismo , Peptídeos
9.
Plant J ; 103(4): 1263-1274, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32623778

RESUMO

Interactions between plant-parasitic nematodes and their hosts are mediated by effectors, i.e. secreted proteins that manipulate the plant to the benefit of the pathogen. To understand the role of effectors in host adaptation in nematodes, we analysed the transcriptome of Heterodera sacchari, a cyst nematode parasite of rice (Oryza sativa) and sugarcane (Saccharum officinarum). A multi-gene phylogenetic analysis showed that H. sacchari and the cereal cyst nematode Heterodera avenae share a common evolutionary origin and that they evolved to parasitise monocot plants from a common dicot-parasitic ancestor. We compared the effector repertoires of H. sacchari with those of the dicot parasites Heterodera glycines and Globodera rostochiensis to understand the consequences of this transition. While, in general, effector repertoires are similar between the species, comparing effectors and non-effectors of H. sacchari and G. rostochiensis shows that effectors have accumulated more mutations than non-effectors. Although most effectors show conserved spatiotemporal expression profiles and likely function, some H. sacchari effectors are adapted to monocots. This is exemplified by the plant-peptide hormone mimics, the CLAVATA3/EMBRYO SURROUNDING REGION-like (CLE) effectors. Peptide hormones encoded by H. sacchari CLE effectors are more similar to those from rice than those from other plants, or those from other plant-parasitic nematodes. We experimentally validated the functional significance of these observations by demonstrating that CLE peptides encoded by H. sacchari induce a short root phenotype in rice, whereas those from a related dicot parasite do not. These data provide a functional example of effector evolution that co-occurred with the transition from a dicot-parasitic to a monocot-parasitic lifestyle.


Assuntos
Doenças das Plantas/parasitologia , Tylenchoidea/metabolismo , Tylenchoidea/patogenicidade , Animais , Proteínas de Helminto/genética , Proteínas de Helminto/metabolismo , Interações Hospedeiro-Parasita , Hormônios Peptídicos/genética , Hormônios Peptídicos/metabolismo , Transcriptoma/genética , Tylenchoidea/genética
10.
BMC Genomics ; 22(1): 611, 2021 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-34380421

RESUMO

BACKGROUND: Potato cyst nematodes belong to the most harmful pathogens in potato, and durable management of these parasites largely depends on host-plant resistances. These resistances are pathotype specific. The current Globodera rostochiensis pathotype scheme that defines five pathotypes (Ro1 - Ro5) is both fundamentally and practically of limited value. Hence, resistant potato varieties are used worldwide in a poorly informed manner. RESULTS: We generated two novel reference genomes of G. rostochiensis inbred lines derived from a Ro1 and a Ro5 population. These genome sequences comprise 173 and 189 scaffolds respectively, marking a ≈ 24-fold reduction in fragmentation as compared to the current reference genome. We provide copy number variations for 19 effector families. Four dorsal gland effector families were investigated in more detail. SPRYSECs, known to be implicated in plant defence suppression, constitute by far the most diversified family studied herein with 60 and 99 variants in Ro1 and Ro5 distributed over 18 and 26 scaffolds. In contrast, CLEs, effectors involved in feeding site induction, show strong physical clustering. The 10 and 16 variants cluster on respectively 2 and 1 scaffolds. Given that pathotypes are defined by their effectoromes, we pinpoint the disparate nature of the contributing effector families in terms of sequence diversification and loss and gain of variants. CONCLUSIONS: Two novel reference genomes allow for nearly complete inventories of effector diversification and physical organisation within and between pathotypes. Combined with insights we provide on effector family-specific diversification patterns, this constitutes a basis for an effectorome-based virulence scheme for this notorious pathogen.


Assuntos
Solanum tuberosum , Tylenchoidea , Animais , Variações do Número de Cópias de DNA , Genômica , Humanos , Solanum tuberosum/genética , Tylenchoidea/genética
11.
Curr Genet ; 67(2): 177-193, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33221975

RESUMO

The kinetochore is a mega-dalton protein assembly that forms within centromeric regions of chromosomes and directs their segregation during cell division. Here we review cell cycle-mediated phosphorylation events at the kinetochore, with a focus on the budding yeast Saccharomyces cerevisiae and the insight gained from forced associations of kinases and phosphatases. The point centromeres found in the budding yeast S. cerevisiae are one of the simplest such structures found in eukaryotes. The S. cerevisiae kinetochore comprises a single nucleosome, containing a centromere-specific H3 variant Cse4CENP-A, bound to a set of kinetochore proteins that connect to a single microtubule. Despite the simplicity of the budding yeast kinetochore, the proteins are mostly homologous with their mammalian counterparts. In some cases, human proteins can complement their yeast orthologs. Like its mammalian equivalent, the regulation of the budding yeast kinetochore is complex: integrating signals from the cell cycle, checkpoints, error correction, and stress pathways. The regulatory signals from these diverse pathways are integrated at the kinetochore by post-translational modifications, notably phosphorylation and dephosphorylation, to control chromosome segregation. Here we highlight the complex interplay between the activity of the different cell-cycle kinases and phosphatases at the kinetochore, emphasizing how much more we have to understand this essential structure.


Assuntos
Ciclo Celular/genética , Proteínas Cromossômicas não Histona/genética , Segregação de Cromossomos/genética , Proteínas de Ligação a DNA/genética , Cinetocoros , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Ciclo Celular/genética , Centrômero/genética , Humanos , Fosforilação/genética
12.
J Exp Bot ; 2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34453432

RESUMO

The potato cyst nematode Globodera pallida acquires all of its nutrients from an elaborate feeding site that it establishes in a host plant root. Normal development of the root cells is re-programmed in a process coordinated by secreted nematode effector proteins. The biological function of the G. pallida GpIA7 effector was investigated in this study. GpIA7 is specifically expressed in the subventral pharyngeal glands of pre-parasitic stage nematodes. Ectopic expression of GpIA7 in potato plants affected plant growth and development, suggesting a potential role for this effector in feeding site establishment. Potato plants overexpressing GpIA7 were shorter, with reduced tuber weight and delayed flowering. We provide evidence that GpIA7 associates with the plant growth regulator StEBP1 (ErbB-3 epidermal growth factor receptor-binding protein 1). GpIA7 modulates the regulatory function of StEBP1, altering the expression level of downstream target genes, including ribonucleotide reductase 2, cyclin D3;1, and retinoblastoma related 1, which are down-regulated in plants overexpressing GpIA7. We provide an insight into the molecular mechanism used by the nematode to manipulate the host cell cycle and demonstrate that this may rely, at least in part, on hindering the function of host EBP1.

13.
J Exp Bot ; 2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34310681

RESUMO

The potato cyst nematode Globodera pallida acquires all of its nutrients from an elaborate feeding site that it establishes in a host plant root. Normal development of the root cells is re-programmed in a process coordinated by secreted nematode effector proteins. The biological function of the G. pallida GpIA7 effector was investigated in this study. GpIA7 is specifically expressed in the subventral pharyngeal glands of pre-parasitic stage nematodes. Ectopic expression of GpIA7 in potato plants affected plant growth and development, suggesting a potential role for this effector in feeding site establishment. Potato plants overexpressing GpIA7 were shorter, with reduced tuber weight and delayed flowering. We provide evidence that GpIA7 associates with the plant growth regulator StEBP1 (ErbB-3 epidermal growth factor receptor-binding protein 1). GpIA7 modulates the regulatory function of StEBP1, altering the expression level of downstream target genes, including ribonucleotide reductase 2, cyclin D3;1 and retinoblastoma related 1, which are downregulated in plants overexpressing GpIA7. We provide an insight into the molecular mechanism used by the nematode to manipulate the host cell cycle and provide evidence that this may rely, at least in part, on hindering the function of host EBP1.

14.
BMC Genomics ; 21(1): 221, 2020 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-32156257

RESUMO

BACKGROUND: The creation of arrays of yeast strains each encoding a different protein with constant tags is a powerful method for understanding how genes and their proteins control cell function. As genetic tools become more sophisticated there is a need to create custom libraries encoding proteins fused with specialised tags to query gene function. These include protein tags that enable a multitude of added functionality, such as conditional degradation, fluorescent labelling, relocalization or activation and also DNA and RNA tags that enable barcoding of genes or their mRNA products. Tools for making new libraries or modifying existing ones are becoming available, but are often limited by the number of strains they can be realistically applied to or by the need for a particular starting library. RESULTS: We present a new recombination-based method, CATS - Cas9-Assisted Tag Switching, that switches tags in any existing library of yeast strains. This method employs the reprogrammable RNA guided nuclease, Cas9, to both introduce endogenous double strand breaks into the genome as well as liberating a linear DNA template molecule from a plasmid. It exploits the relatively high efficiency of homologous recombination in budding yeast compared with non-homologous end joining. CONCLUSIONS: The method takes less than 2 weeks, is cost effective and can simultaneously introduce multiple genetic changes, thus providing a rapid, genome-wide approach to genetic modification.


Assuntos
Proteína 9 Associada à CRISPR/metabolismo , Proteínas de Fluorescência Verde/genética , Peptídeos/genética , Saccharomyces cerevisiae/crescimento & desenvolvimento , Sistemas CRISPR-Cas , Edição de Genes , Proteínas de Fluorescência Verde/metabolismo , Ensaios de Triagem em Larga Escala , Peptídeos/metabolismo , Plasmídeos/genética , RNA Guia de Cinetoplastídeos/genética , Saccharomyces cerevisiae/genética , Coloração e Rotulagem
15.
PLoS Genet ; 12(2): e1005855, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26891228

RESUMO

The accurate segregation of chromosomes during cell division is achieved by attachment of chromosomes to the mitotic spindle via the kinetochore, a large multi-protein complex that assembles on centromeres. The budding yeast kinetochore comprises more than 60 different proteins. Although the structure and function of many of these proteins has been investigated, we have little understanding of the steady state regulation of kinetochores. The primary model of kinetochore homeostasis suggests that kinetochores assemble hierarchically from the centromeric DNA via the inclusion of a centromere-specific histone into chromatin. We tested this model by trying to perturb kinetochore protein levels by overexpressing an outer kinetochore gene, MTW1. This increase in protein failed to change protein recruitment, consistent with the hierarchical assembly model. However, we find that deletion of Psh1, a key ubiquitin ligase that is known to restrict inner kinetochore protein loading, does not increase levels of outer kinetochore proteins, thus breaking the normal kinetochore stoichiometry. This perturbation leads to chromosome segregation defects, which can be partially suppressed by mutation of Ubr2, a second ubiquitin ligase that normally restricts protein levels at the outer kinetochore. Together these data show that Psh1 and Ubr2 synergistically control the amount of proteins at the kinetochore.


Assuntos
Cinetocoros/metabolismo , Fatores de Alongamento de Peptídeos/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Proteínas Cromossômicas não Histona/genética , Proteínas Cromossômicas não Histona/metabolismo , Segregação de Cromossomos , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Regulação Fúngica da Expressão Gênica , Meiose , Mutação , Fatores de Alongamento de Peptídeos/genética , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Ubiquitina-Proteína Ligases/genética
16.
Proc Natl Acad Sci U S A ; 112(33): 10413-8, 2015 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-26240346

RESUMO

The location of proteins within eukaryotic cells is often critical for their function and relocation of proteins forms the mainstay of regulatory pathways. To assess the importance of protein location to cellular homeostasis, we have developed a methodology to systematically create binary physical interactions between a query protein and most other members of the proteome. This method allows us to rapidly assess which of the thousands of possible protein interactions modify a phenotype. As proof of principle we studied the kinetochore, a multiprotein assembly that links centromeres to the microtubules of the spindle during cell division. In budding yeast, the kinetochores from the 16 chromosomes cluster together to a single location within the nucleus. The many proteins that make up the kinetochore are regulated through ubiquitylation and phosphorylation. By systematically associating members of the proteome to the kinetochore, we determine which fusions affect its normal function. We identify a number of candidate kinetochore regulators, including the phosphatase Cdc14. We examine where within the kinetochore Cdc14 can act and show that the effect is limited to regions that correlate with known phosphorylation sites, demonstrating the importance of serine phospho-regulation for normal kinetochore homeostasis.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Cinetocoros/metabolismo , Proteínas Tirosina Fosfatases/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Alelos , Divisão Celular , Proteínas de Fluorescência Verde/metabolismo , Homeostase , Microtúbulos/metabolismo , Mutação , Fenótipo , Monoéster Fosfórico Hidrolases/metabolismo , Fosforilação , Ligação Proteica , Mapeamento de Interação de Proteínas , Proteoma/metabolismo , Proteômica , Saccharomyces cerevisiae/genética , Fuso Acromático
17.
BMC Genomics ; 17: 172, 2016 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-26935069

RESUMO

BACKGROUND: Aphids are phloem-feeding insects that cause significant economic losses to agriculture worldwide. While feeding and probing these insects deliver molecules, called effectors, inside their host to enable infestation. The identification and characterization of these effectors from different species that vary in their host range is an important step in understanding the infestation success of aphids and aphid host range variation. This study employs a multi-disciplinary approach based on transcriptome sequencing and proteomics to identify and compare effector candidates from the broad host range aphid Myzus persicae (green peach aphid) (genotypes O, J and F), and narrow host range aphids Myzus cerasi (black cherry aphid) and Rhopalosiphum padi (bird-cherry oat aphid). RESULTS: Using a combination of aphid transcriptome sequencing on libraries derived from head versus body tissues as well as saliva proteomics we were able to predict candidate effectors repertoires from the different aphid species and genotypes. Among the identified conserved or core effector sets, we identified a significant number of previously identified aphid candidate effectors indicating these proteins may be involved in general infestation strategies. Moreover, we identified aphid candidate effector sequences that were specific to one species, which are interesting candidates for further validation and characterization with regards to species-specific functions during infestation. We assessed our candidate effector repertoires for evidence of positive selection, and identified 49 candidates with DN/DS ratios >1. We noted higher rates of DN/DS ratios in predicted aphid effectors than non-effectors. Whether this reflects positive selection due to co-evolution with host plants, or increased neofunctionalization upon gene duplication remains to be investigated. CONCLUSION: Our work provides a comprehensive overview of the candidate effector repertoires from three different aphid species with varying host ranges. Comparative analyses revealed candidate effectors that are most likely are involved in general aspects of infestation, whereas others, that are highly divergent, may be involved in specific processes important for certain aphid species. Insights into the overlap and differences in aphid effector repertoires are important in understanding how different species successfully infest different ranges of plant species.


Assuntos
Afídeos/genética , Proteoma/genética , Transcriptoma , Sequência de Aminoácidos , Animais , Análise por Conglomerados , Genótipo , Especificidade de Hospedeiro , Proteínas de Insetos/genética , Dados de Sequência Molecular , Saliva/química , Seleção Genética , Análise de Sequência de RNA , Especificidade da Espécie
18.
BMC Genomics ; 15: 923, 2014 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-25342461

RESUMO

BACKGROUND: The potato cyst nematode Globodera pallida has biotrophic interactions with its host. The nematode induces a feeding structure - the syncytium - which it keeps alive for the duration of the life cycle and on which it depends for all nutrients required to develop to the adult stage. Interactions of G. pallida with the host are mediated by effectors, which are produced in two sets of gland cells. These effectors suppress host defences, facilitate migration and induce the formation of the syncytium. RESULTS: The recent completion of the G. pallida genome sequence has allowed us to identify the effector complement from this species. We identify 128 orthologues of effectors from other nematodes as well as 117 novel effector candidates. We have used in situ hybridisation to confirm gland cell expression of a subset of these effectors, demonstrating the validity of our effector identification approach. We have examined the expression profiles of all effector candidates using RNAseq; this analysis shows that the majority of effectors fall into one of three clusters of sequences showing conserved expression characteristics (invasive stage nematode only, parasitic stage only or invasive stage and adult male only). We demonstrate that further diversity in the effector pool is generated by alternative splicing. In addition, we show that effectors target a diverse range of structures in plant cells, including the peroxisome. This is the first identification of effectors from any plant pathogen that target this structure. CONCLUSION: This is the first genome scale search for effectors, combined to a life-cycle expression analysis, for any plant-parasitic nematode. We show that, like other phylogenetically unrelated plant pathogens, plant parasitic nematodes deploy hundreds of effectors in order to parasitise plants, with different effectors required for different phases of the infection process.


Assuntos
Genômica , Proteínas de Helminto/genética , Doenças das Plantas/parasitologia , Solanum tuberosum/parasitologia , Tylenchoidea/genética , Tylenchoidea/fisiologia , Processamento Alternativo , Animais , Feminino , Proteínas de Helminto/metabolismo , Espaço Intracelular/parasitologia , Estágios do Ciclo de Vida/genética , Masculino , Solanum tuberosum/citologia , Tylenchoidea/crescimento & desenvolvimento , Tylenchoidea/metabolismo
19.
Cell Genom ; 4(6): 100580, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38815588

RESUMO

Pathogens are engaged in a fierce evolutionary arms race with their host. The genes at the forefront of the engagement between kingdoms are often part of diverse and highly mutable gene families. Even in this context, we discovered unprecedented variation in the hyper-variable (HYP) effectors of plant-parasitic nematodes. HYP effectors are single-gene loci that potentially harbor thousands of alleles. Alleles vary in the organization, as well as the number, of motifs within a central hyper-variable domain (HVD). We dramatically expand the HYP repertoire of two plant-parasitic nematodes and define distinct species-specific "rules" underlying the apparently flawless genetic rearrangements. Finally, by analyzing the HYPs in 68 individual nematodes, we unexpectedly found that despite the huge number of alleles, most individuals are germline homozygous. These data support a mechanism of programmed genetic variation, termed HVD editing, where alterations are locus specific, strictly governed by rules, and theoretically produce thousands of variants without errors.


Assuntos
Alelos , Animais , Plantas/parasitologia , Plantas/genética , Nematoides/genética , Variação Genética/genética , Doenças das Plantas/parasitologia
20.
Nat Commun ; 15(1): 5001, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38866741

RESUMO

Theory predicts that compensatory genetic changes reduce negative indirect effects of selected variants during adaptive evolution, but evidence is scarce. Here, we test this in a wild population of Hawaiian crickets using temporal genomics and a high-quality chromosome-level cricket genome. In this population, a mutation, flatwing, silences males and rapidly spread due to an acoustically-orienting parasitoid. Our sampling spanned a social transition during which flatwing fixed and the population went silent. We find long-range linkage disequilibrium around the putative flatwing locus was maintained over time, and hitchhiking genes had functions related to negative flatwing-associated effects. We develop a combinatorial enrichment approach using transcriptome data to test for compensatory, intragenomic coevolution. Temporal changes in genomic selection were distributed genome-wide and functionally associated with the population's transition to silence, particularly behavioural responses to silent environments. Our results demonstrate how 'adaptation begets adaptation'; changes to the sociogenetic environment accompanying rapid trait evolution can generate selection provoking further, compensatory adaptation.


Assuntos
Genômica , Gryllidae , Animais , Gryllidae/genética , Gryllidae/fisiologia , Masculino , Genômica/métodos , Havaí , Adaptação Fisiológica/genética , Desequilíbrio de Ligação , Genoma de Inseto , Evolução Biológica , Feminino , Mutação , Seleção Genética , Evolução Molecular , Transcriptoma/genética
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