RESUMO
The microbial consortia of lactic acid bacteria and yeast of sourdough can partially degrade gluten subunits associated with wheat-related diseases. This study evaluated how sourdough fermentation interferes with wheat protein profiles and if it can be related to the reduction expression of allergenic proteins. Samples from five bread doughs (Saccharomyces cerevisiae -C1; chemical acidification -C2, and three sourdoughs formulations -S1, S2, and S3) were sequentially extracted, digested, and submitted to shotgun label-free proteomic analysis. Eight-five proteins were identified as allergenic, mainly belonging to gliadin fraction, including seven containing the 33-mer peptide sequence. The highest immunogenic potential was found in dough C1 and S3, while the least reactive group consisted of S1 and C2. The two folds down expression of an α-gliadin containing the 33-mer sequence corroborates this. This finding may indicate the role of organic acids produced by the microbiota sourdough type II during fermentation in changing the protein profile.
Assuntos
Alérgenos , Alimentos Fermentados , Alérgenos/análise , Triticum/metabolismo , Fermentação , Proteômica , Gliadina/metabolismo , Saccharomyces cerevisiae/metabolismo , Pão/análise , Farinha/análise , Microbiologia de AlimentosRESUMO
Telomeres cap and protect the linear eukaryotic chromosomes. Telomere length is determined by an equilibrium between positive and negative regulators of telomerase activity. A systematic screen for yeast mutants that affect telomere length maintenance in the yeast Saccharomyces cerevisiae revealed that mutations in any of ~500 genes affects telomere length. One of the genes that, when mutated, causes telomere elongation is ELG1, which encodes an unloader of PCNA, the processivity factor for replicative DNA polymerases. PCNA can undergo SUMOylation on two conserved residues, K164 and K127, or ubiquitination at lysine 164. These modifications have already been implicated in genome stability processes. We report that SUMOylated PCNA acts as a signal that positively regulates telomerase activity. We also uncovered physical interactions between Elg1 and the CST (Cdc13-Stn1-Ten) complex and addressed the mechanism by which Elg1 and Stn1 negatively regulates telomere elongation, coordinated by SUMO. We discuss these results with respect to how chromosomal replication and telomere elongation are coordinated.
Assuntos
Proteínas de Saccharomyces cerevisiae , Telomerase , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Antígeno Nuclear de Célula em Proliferação/genética , Telomerase/metabolismo , Proteínas de Ligação a Telômeros/genética , Proteínas de Ligação a Telômeros/metabolismo , Ligação Proteica , Telômero/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Transporte/metabolismoRESUMO
Olorofim is a new antifungal in clinical development which has a novel mechanism of action against dihydroorotate dehydrogenase (DHODH). DHODH form a ubiquitous family of enzymes in the de novo pyrimidine biosynthetic pathway and are split into class 1A, class 1B and class 2. Olorofim specifically targets the fungal class 2 DHODH present in a range of pathogenic moulds. The nature and number of DHODH present in many fungal species have not been addressed for large clades of this kingdom. Mucorales species do not respond to olorofim; previous work suggests they have only class 1A DHODH and so lack the class 2 target that olorofim inhibits. The dematiaceous moulds have mixed susceptibility to olorofim, yet previous analyses imply that they have class 2 DHODH. As this is at odds with their intermediate susceptibility to olorofim, we hypothesised that these pathogens may maintain a second class of DHODH, facilitating pyrimidine biosynthesis in the presence of olorofim. The aim of this study was to investigate the DHODH repertoire of clinically relevant species of Mucorales and dematiaceous moulds to further characterise these pathogens and understand variations in olorofim susceptibility. Using bioinformatic analysis, S. cerevisiae complementation and biochemical assays of recombinant protein, we provide the first evidence that two representative members of the Mucorales have only class 1A DHODH, substantiating a lack of olorofim susceptibility. In contrast, bioinformatic analyses initially suggested that seven dematiaceous species appeared to harbour both class 1A-like and class 2-like DHODH genes. However, further experimental investigation of the putative class 1A-like genes through yeast complementation and biochemical assays characterised them as dihydrouracil oxidases rather than DHODHs. These data demonstrate variation in dematiaceous mould olorofim susceptibility is not due to a secondary DHODH and builds on the growing picture of fungal dihydrouracil oxidases as an example of horizontal gene transfer.
Assuntos
Mucorales , Oxirredutases atuantes sobre Doadores de Grupo CH-CH , Di-Hidro-Orotato Desidrogenase , Saccharomyces cerevisiae/metabolismo , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/genética , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/metabolismo , Pirimidinas/farmacologiaRESUMO
Selective degradation of unnecessary or abnormal proteins by the ubiquitin-proteasome system is an essential part of proteostasis. Ubiquitin ligases recognize substrates of selective protein degradation and modify them with polyubiquitin chains, which mark them for proteasomal degradation. Substrate recognition by ubiquitin ligases often involves degradation signals or degrons, which are typically short linear motifs found in intrinsically disordered regions, e.g., at protein termini. However, specificity in selective protein degradation is generally not well understood, as for most ubiquitin ligases no degrons have been identified thus far. To address this limitation, high-throughput mutagenesis approaches, such as multiplexed protein stability (MPS) profiling, have been developed, enabling systematic surveys of degrons in vivo or allowing to define degron motifs recognized by different ubiquitin ligases. In MPS profiling, thousands of short peptides can be assessed in parallel for their ability to trigger degradation of a fluorescent timer reporter. Here, we describe common types of libraries used to identify and dissect degrons located at protein termini using MPS profiling in budding yeast, and provide protocols for their construction.
Assuntos
Complexo de Endopeptidases do Proteassoma , Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteólise , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteínas/metabolismo , Ubiquitina/metabolismo , Ubiquitina-Proteína Ligases/metabolismoRESUMO
Heterologous expression of enzymes can generate a background-free environment that facilitates investigation of enzyme properties, for instance to focus on particular isoforms in case of gene families, or on individual splicing variants. If a proper host can be found, in vivo assays are often simpler than overexpression and purification, followed by in vitro measurements, would be. We expressed plant ubiquitin ligase PRT6 in the budding yeast Saccharomyces cerevisiae for studies on activity and substrate preferences. Expression of this large enzyme profits from the eukaryotic folding catalysis provided by budding yeast, and from the presence of endogenous ubiquitin activating enzyme. While yeast encodes a ubiquitin ligase, Ubr1, that is functionally related to PRT6, a strain with deletion of the UBR1 gene offers a background-free host. Two different substrates were analyzed. One was a model substate, and the other one a natural substrate fused to a reporter. Two different methods were compared for assessment of protein stability. A method based on internal standardization via tandem fluorescent timer measurement turned out to be complementary to standardization based on cell culture density.
Assuntos
Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Saccharomyces cerevisiae/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Ubiquitinação , Ubiquitina/metabolismoRESUMO
N-terminal protein sequences and their proteolytic processing and modifications influence the stability and turnover of proteins by creating potential degrons for cellular proteolytic pathways. Understanding the impact of genetic perturbations of components affecting the processing of protein N-termini and thereby their stability, requires methods compatible with proteome-wide studies of many N-termini simultaneously. Tandem fluorescent timers (tFT) allow the in vivo measurement of protein turnover completely independent of protein abundance and can be deployed for proteome-wide studies. Here we present a protocol for Multiplexed Protein Stability (MPS) profiling of tFT-libraries encoding large numbers of different protein N-termini fused to tFT in the yeast Saccharomyces cerevisiae. This protocol includes fluorescence cell sorting based profiling of these libraries using a pooling approach. Analysis of the sorted pools is done by using multiplexed deep sequencing, in order to generate a stability index for each N-terminally peptide fused to the tFT reporter, and to evaluate half-life changes across all species represented in the library.
Assuntos
Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteoma/metabolismo , Proteólise , Sequência de Aminoácidos , Estabilidade Proteica , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismoRESUMO
BACKGROUND: In plants, RNase III Dicer-like proteins (DCLs) act as sensors of dsRNAs and process them into short 21- to 24-nucleotide (nt) (s)RNAs. Plant DCL4 is involved in the biogenesis of either functional endogenous or exogenous (i.e. viral) short interfering (si)RNAs, thus playing crucial antiviral roles. METHODS: In this study we expressed plant DCL4 in Saccharomyces cerevisiae, an RNAi-depleted organism, in which we could highlight the role of dicing as neither Argonautes nor RNA-dependent RNA polymerase is present. We have therefore tested the DCL4 functionality in processing exogenous dsRNA-like substrates, such as a replicase-assisted viral replicon defective-interfering RNA and RNA hairpin substrates, or endogenous antisense transcripts. RESULTS: DCL4 was shown to be functional in processing dsRNA-like molecules in vitro and in vivo into 21- and 22-nt sRNAs. Conversely, DCL4 did not efficiently process a replicase-assisted viral replicon in vivo, providing evidence that viral RNAs are not accessible to DCL4 in membranes associated in active replication. Worthy of note, in yeast cells expressing DCL4, 21- and 22-nt sRNAs are associated with endogenous loci. CONCLUSIONS: We provide new keys to interpret what was studied so far on antiviral DCL4 in the host system. The results all together confirm the role of sense/antisense RNA-based regulation of gene expression, expanding the sense/antisense atlas of S. cerevisiae. The results described herein show that S. cerevisiae can provide insights into the functionality of plant dicers and extend the S. cerevisiae tool to new biotechnological applications.
Assuntos
Proteínas de Plantas , Saccharomyces cerevisiae , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Interferência de RNA , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Ribonuclease III/genética , Ribonuclease III/metabolismo , RNA de Cadeia Dupla/genética , RNA Interferente Pequeno/metabolismoRESUMO
Sesquiterpene synthases convert farnesyl diphosphate into various sesquiterpenes, which find wide applications in the food, cosmetics and pharmaceutical industries. Although numerous putative sesquiterpene synthases have been identified in fungal genomes, many lack biochemical characterization. In this study, we identified a putative terpene synthase AcTPS3 from Acremonium chrysogenum. Through sequence analysis and in vitro enzyme assay, AcTPS3 was identified as a sesquiterpene synthase. To obtain sufficient product for NMR testing, a metabolic engineered Saccharomyces cerevisiae was constructed to overproduce the product of AcTPS3. The major product of AcTPS3 was identified as (+)-cubenene (55.46%) by GC-MS and NMR. Thus, AcTPS3 was confirmed as (+)-cubenene synthase, which is the first report of (+)-cubenene synthase. The optimized S. cerevisiae strain achieved a biosynthesis titer of 597.3 mg/L, the highest reported for (+)-cubenene synthesis.
Assuntos
Acremonium , Alquil e Aril Transferases , Sesquiterpenos , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Sesquiterpenos/química , Acremonium/genética , Acremonium/metabolismo , Genoma Fúngico , Alquil e Aril Transferases/genética , Alquil e Aril Transferases/metabolismoRESUMO
The growing accessibility of large-scale protein interaction data demands extensive research to understand cell organization and its functioning at the network level. Bioinformatics and data mining researchers have extensively studied network clustering to examine the structural and operational features of protein protein interaction (PPI) networks. Clustering PPI networks has proven useful in numerous research over the past two decades for identifying functional modules, understanding the roles of previously unknown proteins, and other purposes. Protein complexes represent one of the essential cellular components for creating biological activities. Inferring protein complexes has been made more accessible by experimental approaches. We offer a novel method that integrates the classification model with local topological data, making it more reliable and efficient. This article describes a decision tree classifier based on topological characteristics of the subgraph for mining protein complexes. The proposed graph-based algorithm is an effective and efficient way to identify protein complexes from large-scale PPI networks. The performance of the proposed algorithm is observed in protein-protein interaction networks of yeast and human in the Database of Interacting Proteins (DIP) and the Biological General Repository for Interaction Datasets (BioGRID) using widely accepted benchmark protein complexes from the comprehensive resource of mammalian protein complexes (CORUM) and the comprehensive catalogue of yeast protein complexes (CYC2008). The outcomes demonstrate that our method can outperform the best-performing supervised, semi-supervised, and unsupervised approaches to detecting protein complexes.
Assuntos
Mapeamento de Interação de Proteínas , Mapas de Interação de Proteínas , Humanos , Mapeamento de Interação de Proteínas/métodos , Proteínas Fúngicas/metabolismo , Saccharomyces cerevisiae/metabolismo , Algoritmos , Biologia Computacional/métodos , Análise por Conglomerados , Árvores de DecisõesRESUMO
α-Farnesene, a type of acyclic sesquiterpene, is an important raw material in agriculture, aircraft fuel, and the chemical industry. In this study, we constructed an efficient α-farnesene-producing yeast cell factory by combining enzyme and metabolic engineering strategies. First, we screened different plants for α-farnesene synthase (AFS) with the best activity and found that AFS from Camellia sinensis (CsAFS) exhibited the most efficient α-farnesene production in Saccharomyces cerevisiae 4741. Second, the metabolic flux of the mevalonate pathway was increased to improve the supply of the precursor farnesyl pyrophosphate. Third, inducing site-directed mutagenesis in CsAFS, the CsAFSW281C variant was obtained, which considerably increased α-farnesene production. Fourth, the N-terminal serine-lysine-isoleucine-lysine (SKIK) tag was introduced to construct the SKIKâ¼CsAFSW281C variant, which further increased α-farnesene production to 2.8 g/L in shake-flask cultures. Finally, the α-farnesene titer of 28.3 g/L in S. cerevisiae was obtained by fed-batch fermentation in a 5 L bioreactor.
Assuntos
Saccharomyces cerevisiae , Engenharia Metabólica , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Filogenia , Pirofosfatases/genética , Pirofosfatases/metabolismo , Mutagênese Sítio-DirigidaRESUMO
Sherry wine is a pale-yellowish dry wine produced in Southern-Spain which features are mainly due to biological aging when the metabolism of biofilm-forming yeasts (flor yeasts) consumes ethanol (and other non-fermentable carbon sources) from a previous alcoholic fermentation, and produces volatile compounds such as acetaldehyde. To start aging and maintain the wine stability, a high alcohol content is required, which is achieved by the previous fermentation or by adding ethanol (fortification). Here, an alternative method is proposed which aims to produce a more economic, distinctive Sherry wine without fortification. For this, a flor yeast has been pre-acclimatized to glycerol consumption against ethanol, and later confined in a fungal-based immobilization system known as "microbial biocapsules", to facilitate its inoculum. Once aged, the wines produced using biocapsules and free yeasts (the conventional method) exhibited chemical differences in terms of acidity and volatile concentrations. These differences were evaluated positively by a sensory panel. Pre-acclimatization of flor yeasts to glycerol consumption was not successful but when cells were immobilized in fungal pellets, ethanol consumption was lower. We believe that immobilization of flor yeasts in microbial biocapsules is an economic technique that can be used to produce high quality differentiated Sherry wines.
Assuntos
Saccharomyces cerevisiae , Vinho , Saccharomyces cerevisiae/metabolismo , Vinho/microbiologia , Glicerol/metabolismo , Acetaldeído/análise , Acetaldeído/metabolismo , Etanol/metabolismo , FermentaçãoRESUMO
HLA-E is a non-classical class I MHC protein involved in innate and adaptive immune recognition. While recent studies have shown HLA-E can present diverse peptides to NK cells and T cells, the HLA-E repertoire recognized by CD94/NKG2x has remained poorly defined, with only a limited number of peptide ligands identified. Here we screen a yeast-displayed peptide library in the context of HLA-E to identify 500 high-confidence unique peptides that bind both HLA-E and CD94/NKG2A or CD94/NKG2C. Utilizing the sequences identified via yeast display selections, we train prediction algorithms and identify human and cytomegalovirus (CMV) proteome-derived, HLA-E-presented peptides capable of binding and signaling through both CD94/NKG2A and CD94/NKG2C. In addition, we identify peptides which selectively activate NKG2C+ NK cells. Taken together, characterization of the HLA-E-binding peptide repertoire and identification of NK activity-modulating peptides present opportunities for studies of NK cell regulation in health and disease, in addition to vaccine and therapeutic design.
Assuntos
Antígenos de Histocompatibilidade Classe I , Saccharomyces cerevisiae , Humanos , Ligantes , Saccharomyces cerevisiae/metabolismo , Ligação Proteica , Antígenos de Histocompatibilidade Classe I/metabolismo , Peptídeos/química , Células Matadoras NaturaisRESUMO
High concentrations of ethanol could cause intracellular oxidative stress in yeast, which can lead to ethanol-oxidation cross-stress. Antioxidant dipeptides are effective in maintaining cell viability and stress tolerance under ethanol-oxidation cross-stress. In this study, we sought to elucidate how antioxidant dipeptides affect the yeast cell wall and membrane defense systems to enhance stress tolerance. Results showed that antioxidant dipeptide supplementation reduced cell leakage of nucleic acids and proteins by changing cell wall components under ethanol-oxidation cross-stress. Antioxidant dipeptides positively modulated the cell wall integrity pathway and up-regulated the expression of key genes. Antioxidant dipeptides also improved the cell membrane integrity by increasing the proportion of unsaturated fatty acids and regulating the expression of key fatty acid synthesis genes. Moreover, the addition of antioxidant dipeptides significantly (p < 0.05) increased the content of ergosterol. Ala-His (AH) supplementation caused the highest content of ergosterol, with an increase of 23.68 ± 0.01% compared to the control, followed by Phe-Cys (FC) and Thr-Tyr (TY). These results revealed that the improvement of the cell wall and membrane functions of antioxidant dipeptides was responsible for enhancing the ethanol-oxidation cross-stress tolerance of yeast.
Assuntos
Antioxidantes , Saccharomyces cerevisiae , Antioxidantes/farmacologia , Antioxidantes/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Parede Celular/metabolismo , Membrana Celular/metabolismo , Etanol/metabolismo , Ergosterol , Dipeptídeos/farmacologia , Dipeptídeos/metabolismoRESUMO
Introducing nitrogen fixation (nif â) genes into eukaryotic genomes and targeting Nif components to mitochondria or chloroplasts is a promising strategy for engineering nitrogen-fixing plants. A prerequisite for achieving nitrogen fixation in crops is stable and stoichiometric expression of each component in organelles. Previously, we designed a polyprotein-based nitrogenase system depending on Tobacco Etch Virus protease (TEVp) to release functional Nif components from five polyproteins. Although this system satisfies the demand for specific expression ratios of Nif components in Escherichia coli, we encountered issues with TEVp cleavage of polyproteins targeted to yeast mitochondria. To overcome this obstacle, a version of the Nif polyprotein system was constructed by replacing TEVp cleavage sites with minimal peptide sequences, identified by knowledge-based engineering, that are susceptible to cleavage by the endogenous mitochondrial-processing peptidase. This replacement not only further reduces the number of genes required, but also prevents potential precleavage of polyproteins outside the target organelle. This version of the polyprotein-based nitrogenase system achieved levels of nitrogenase activity in E. coli, comparable to those observed with the TEVp-based polyprotein nitrogenase system. When applied to yeast mitochondria, stable and balanced expression of Nif components was realized. This strategy has potential advantages, not only for transferring nitrogen fixation to eukaryotic cells, but also for the engineering of other metabolic pathways that require mitochondrial compartmentalization.
Assuntos
Escherichia coli , Fixação de Nitrogênio , Fixação de Nitrogênio/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Saccharomyces cerevisiae/metabolismo , Poliproteínas/genética , Poliproteínas/metabolismo , Nitrogenase/metabolismo , Mitocôndrias/genética , Mitocôndrias/metabolismo , Nitrogênio/metabolismoRESUMO
MOTIVATION: Protein complexes are groups of polypeptide chains linked by non-covalent protein-protein interactions, which play important roles in biological systems and perform numerous functions, including DNA transcription, mRNA translation, and signal transduction. In the past decade, a number of computational methods have been developed to identify protein complexes from protein interaction networks by mining dense subnetworks or subgraphs. RESULTS: In this article, different from the existing works, we propose a novel approach for this task based on generative adversarial networks, which is called PCGAN, meaning identifying Protein Complexes by GAN. With the help of some real complexes as training samples, our method can learn a model to generate new complexes from a protein interaction network. To effectively support model training and testing, we construct two more comprehensive and reliable protein interaction networks and a larger gold standard complex set by merging existing ones of the same organism (including human and yeast). Extensive comparison studies indicate that our method is superior to existing protein complex identification methods in terms of various performance metrics. Furthermore, functional enrichment analysis shows that the identified complexes are of high biological significance, which indicates that these generated protein complexes are very possibly real complexes. AVAILABILITY AND IMPLEMENTATION: https://github.com/yul-pan/PCGAN.
Assuntos
Mapas de Interação de Proteínas , Saccharomyces cerevisiae , Humanos , Saccharomyces cerevisiae/metabolismo , Transdução de Sinais , Biossíntese de ProteínasRESUMO
Induction of unfolded protein response involves activation of transcription factor Hac1p that is encoded by HAC1 pre-mRNA harboring an intron and a bipartite element (BE), which is subjected to nuclear mRNA decay by the nuclear exosome/Cbc1p-Tif4631p-dependent Exosome Targeting (CTEXT) complex. Using a combination of genetic and biochemical approaches, we demonstrate that a Rab-GTPase Ypt1p controls unfolded protein response signaling dynamics. This regulation relies on the nuclear localization of a small fraction of the cellular Ypt1p pool in the absence of endoplasmic reticulum (ER)-stress causing a strong association of the nuclear Ypt1p with pre-HAC1 mRNA that eventually promotes sequential recruitments of NNS, CTEXT, and the nuclear exosome onto this pre-mRNA. Recruitment of these decay factors onto pre-HAC1 mRNA is accompanied by its rapid nuclear decay that produces a precursor RNA pool lacking functional BE thereby causing its inefficient targeting to Ire1p foci leading to their diminished splicing and translation. ER stress triggers rapid relocalization of the nuclear pool of Ypt1p to the cytoplasm leading to its dissociation from pre-HAC1 mRNA thereby causing decreased recruitment of these decay factors to precursor HAC1 RNA leading to its diminished degradation. Reduced decay results in an increased abundance of pre-HAC1 mRNA with intact functional BE leading to its enhanced recruitment to Ire1p foci.
Assuntos
Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Fatores de Transcrição de Zíper de Leucina Básica/genética , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Proteínas rab de Ligação ao GTP/metabolismo , Proteínas Repressoras/metabolismo , Precursores de RNA/genética , Splicing de RNA/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Resposta a Proteínas não DobradasRESUMO
Motile cilia lining on the ependymal cells are crucial for cerebrospinal fluid (CSF) flow and its dysfunction is often associated with hydrocephalus. Unc51-like-kinase 4 (Ulk4) was previously linked to CSF flow and motile ciliogenesis in mice, as the hypomorph mutant of Ulk4 (Ulk4tm1a/tm1a ) developed hydrocephalic phenotype resulted from defective ciliogenesis and disturbed ciliary motility, while the underling mechanism is largely obscure. Here, we report that serine/threonine kinase 36 (STK36), a paralog of ULK4, directly interacts with ULK4 and this was demonstrated by yeast two-hybrid (Y2H) in yeast and coimmunoprecipitation (co-IP) assays in HEK293T cells, respectively. The interaction region was confined to their respective N-terminal kinase domain. The hypomorph mutant of Stk36 (Stk36tmE4-/- ) also developed progressive hydrocephalus postnatally and dysfunctional CSF flow, with multiple defects of motile cilia, including reduced ciliary number, disorganized ciliary orientation, defected axonemal structure and inconsistent base body (BB) orientation. Stk36tmE4-/- also disturbed the expression of Foxj1 transcription factor and a range of other ciliogenesis-related genes. All these morphological changes, motile cilia defects and transcriptional dysregulation in the Stk36tmE4-/- are practically copied from that in Ulk4tm1a/tm1a mice. Taken together, we conclude that both Stk36 and Ulk4 are crucial for CSF flow, they cooperate by direct binding with their kinase domain to regulate the Foxj1 transcription factor pathways for ciliogenesis and cilia function, not limited to CSF flow. The underlying molecular mechanism probably conserved in evolution and could be extended to other metazoans.
Assuntos
Hidrocefalia , Proteínas Quinases , Camundongos , Animais , Humanos , Proteínas Quinases/metabolismo , Saccharomyces cerevisiae/metabolismo , Células HEK293 , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Hidrocefalia/genética , Fatores de Transcrição/metabolismo , Cílios/metabolismoRESUMO
In Saccharomyces cerevisiae, the J-protein Zuo1 and the nonconventional Hsp70 homologue Ssz1 stimulate the ATPase activity of the chaperone proteins Ssb1 and Ssb2 (Ssb1/2), which are associated with the ribosomes. The dephosphorylation of sucrose nonfermenting 1 (Snf1) on Thr210 is required for glucose repression. The Ssb1/2 and 14-3-3 proteins Bmh1 and Bmh2 appear to be responsible for the dephosphorylation of Snf1 on Thr210 and glucose repression. Here, we investigated the role of Zuo1 in glucose repression. The zuo1∆ strain as well as the ssb1∆ssb2∆ strain exhibited a glucose-specific growth defect during logarithmic growth on glucose. Many of the respiratory chain genes examined were statistically significantly upregulated, but less than 2-fold, in the zuo1∆ strain as well as in the ssb1∆ssb2∆ strain on glucose. In addition, excessive phosphorylation of Snf1 on Thr210 was observed in the zuo1∆ strain as well as in the ssb1∆ssb2∆ strain in the presence of glucose. The mRNA levels of SSB1/2 and BMH1 were statistically significantly reduced by approximately 0.5- to 0.8-fold relative to the wild-type level in the zuo1∆ strain on glucose. These results suggest that Zuo1 is responsible for glucose repression, possibly by increasing the mRNA levels of SSB1/2 and BMH1 during growth on glucose.
Assuntos
Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Glucose/metabolismo , Proteínas Ribossômicas/metabolismo , Ribossomos , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismoRESUMO
Permeabilization of mitochondrial membrane by proteins of the BCL-2 family is a key decisive event in the induction of apoptosis in mammalian cells. Although yeast does not have homologs of the BCL-2 family, when these are expressed in yeast, they modulate the survival of cells in a way that corresponds to their activity in mammalian cells. The yeast gene, alternatively referred to as BXI1 or YBH3, encodes for membrane protein in the endoplasmic reticulum that was, contradictorily, shown to either inhibit Bax or to be required for Bax activity. We have tested the effect of the deletion of this gene on the pro-apoptotic activity of Bax and Bak and the anti-apoptotic activity of Bcl-XL and Bcl-2, as well on survival after treatment with inducers of regulated cell death in yeast, hydrogen peroxide and acetic acid. While deletion resulted in increased sensitivity to acetic acid, it did not affect the sensitivity to hydrogen peroxide nor to BCL-2 family members. Thus, our results do not support any model in which the activity of BCL-2 family members is directly affected by BXI1 but rather indicate that it may participate in modulating survival in response to some specific forms of stress.
Assuntos
Peróxido de Hidrogênio , Saccharomyces cerevisiae , Animais , Apoptose/genética , Proteína Killer-Antagonista Homóloga a bcl-2/genética , Proteína Killer-Antagonista Homóloga a bcl-2/metabolismo , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismo , Sobrevivência Celular , Peróxido de Hidrogênio/farmacologia , Peróxido de Hidrogênio/metabolismo , Mamíferos/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Saccharomyces cerevisiae/metabolismoRESUMO
The potential probiotic yeast was isolated from the Kyzyl Anor pomegranate variety growing in the Turkestan region (Kazakhstan). The yeast strain was identified as Saccharomyces cerevisiae Az-12. Molecular genetic identification was carried out using the Sanger sequencing method. The degree of homology of the S. cerevisiae Az-12 strain with the strain MH608341.1 Saccharomyces cerevisiae isolate extr03 was 99.65%. Antagonistic effect of the yeast against pathogenic bacteria was confirmed according inhibition zones for Staphylococcus aureus 13.5 ± 0.05 mm; the inhibition zones for Escherichia coli 12.8 ± 0.05 mm; and 10.7 ± 0.05 mm for Pseudomonas aeruginosa. Scanning microscopy of S. cerevisiae Az-12 and S. aureus confirmed the adhesive ability of the yeast cell surface to S. aureus. S. cerevisiae Az-12 were chosen as the most promising, as they are able to quickly ferment juices. Functional drinks containing pomegranate juice and yeast with a probiotic effect can be considered as a useful synbiotic product formulation.