Project description:Protein ubiquitination plays a vital role in the stress response of diverse filamentous fungi. However, few reports are available on fungal insect pathogens including Metarhizium. Here, we report a comparative ubiquitylome analysis of M. robertsii exposed to heat stress. The growth of M. robertsii was suppressed and protein ubiquitination levels were markedly promoted during heat stress. Compared to the control treatment, there were 4,674 sites with differential ubiquitination, of which 3,419 lysine ubiquitination sites across 1,344 proteins were significantly up-regulated, and 1,255 sites on 750 proteins were down-regulated under heat stress. Further analysis showed that these proteins with up-regulated modified sites were preferentially enriched in the phenylalanine, tyrosine, and tryptophan biosynthesis, pantothenate and CoA biosynthesis, and O-glycan biosynthesis pathways. Proteins with down-regulated modified sites were significantly enriched in different pathways including alanine, aspartate, and glutamate metabolism, pyruvate metabolism, and fatty acid biosynthesis. In particular, a key protein (phosphoenolpyruvate carboxykinase, MrPCK1, a central enzyme in gluconeogenesis and pyruvate metabolism) with five ubiquitination sites was identified, and functional analysis further revealed its regulatory role in heat stress tolerance of M. robertsii. Taken together, our findings suggest that M. robertsii may respond to heat stress not only through the canonical pathway of the proteasome but also by modulating specific metabolic pathways, including pyruvate metabolism (notably via MrPCK1) and potentially fatty acid biosynthesis. The results provide insights into the molecular mechanisms by which ubiquitination regulates the heat stress response in M. robertsii and contribute to our understanding of thermotolerance in filamentous fungi.
Project description:The goal of this study is to identify the different proteins secreted by Mycobacterium bovis in the culture media at different stages of bacterial growth. A field strain of M. bovis was allowed to grow in a culture media and culture supernatant was collected at three-time points representing approximately three different phases of growth. The supernatant was digested by trypsin and analyzed by LC-MS/MS analysis
Project description:Clostridioides difficile BI/NAP1/ribotype 027 is an epidemic hypervirulent strain found worldwide, including in Latin America. We examined the genomes and exoproteomes of two multilocus sequence type (MLST) clade 2 C. difficile strains considered hypervirulent: ICC-45 (ribotype SLO231/UK[CE]821), isolated in Brazil, and NAP1/027/ST01 (LIBA5756), isolated during a 2010 outbreak in Costa Rica. C. difficile isolates were cultured and extracellular proteins were analyzed using high-performance liquid chromatography-tandem mass spectrometry. Genomic analysis revealed that these isolates shared most of the gene composition. Only 83 and 290 NAP1/027 genes were considered singletons in ICC-45 and NAP1/027, respectively. Exoproteome analysis revealed 197 proteins, of which 192 were similar in both strains. Only five proteins were exclusive to the ICC-45 strain. These proteins were involved with catalytic and binding functions and indirectly interacted with proteins related to pathogenicity. Most proteins, including TcdA, TcdB, flagellin subunit, and cell surface protein, were overrepresented in the ICC-45 strain; 14 proteins, including mature S-layer protein, were present in higher proportions in LIBA5756. These data show close similarity between the genome and proteins in the supernatant of two strains with hypervirulent features isolated in Latin America and underscore the importance of epidemiological surveillance of the transmission and emergence of new strains.
Project description:Pectobacterium are Gram-negative rods of the family Pectobacteriaceae. They are the causative agent of soft rot diseases of crops and ornamental plants. However, their virulence mechanisms are not yet fully elucidated. Membrane vesicles (MVs) are universally released by bacteria and are be-lieved to play an important role in pathogenicity, and survival of bacteria in the environment. Our study investigates the role of MVs in the virulence of Pectobacterium. The results indicate that the morphology and yields of MVs depend on medium composition. In polygalacturonic acid (PGA) supplemented media, Pectobacterium produce MVs of a larger size (100-300 nm) apart of vesicles below 100 nm. Proteomic analyses revealed the presence of pectate degrading enzymes in MVs. The pectate plate test and enzymatic assay proved that those enzymes are active and able to de-grade pectates. What is more, pathogenicity test indicated that MVs derived from Pectobacterium were able to induce maceration of Zantedeschia sp. leaves. We also show that MVs of β-lactamase producing strains were able to suppress ampicillin activity and permit the growth of susceptible bacteria. Those findings indicate that MVs of Pectobacterium play an important role in host-pathogen interactions and niche competition with other bacteria. Our research also sheds some light on the mechanism of MVs production. We demonstrate that Pectobacterium strains, which overexpress the green fluorescence protein (GFP), produce more MVs than wild type strains. Moreover, proteomic analysis revealed that GFP was present in MVs. Therefore, we demonstrate that protein sequestration into MVs is not limited strictly to periplasmic proteins and is a common occurrence. Our research highlights the importance of MVs production as a mechanism of cargo delivery in Pectobacterium and an alternative secretion system.
Project description:Following exposure to vaccines, antigen-specific CD8+ T-cell responses develop as long-term memory pools. Novel vaccine strategies based on adenoviral vectors, e.g. those developed for HCV, are able to induce and sustain substantial CD8+ T-cell populations. How such populations evolve following vaccination remains to be defined at a transcriptional level. We addressed the transcriptional regulation of divergent CD8+ T-cell memory pools induced by an adenoviral vector encoding a model antigen (beta-galactosidase). We observe transcriptional profiles that mimic those following infection with persistent pathogens, murine and human cytomegalovirus (CMV). Key transcriptional hallmarks include up-regulation of homing receptors, and anti-apoptotic pathways, driven by conserved networks of transcription factors, including T-bet (TBX21). In humans, a novel adenovirus vaccine induced similar CMV-like phenotypes and underlying transcription factor regulation. These data clarify the core features of CD8+ T-cell memory following vaccination with adenovirus vectors and indicate a conserved pathway for memory development shared with persistent herpesviruses. Total RNA was extracted from sorted memory CD8 T cells induce by CMV and adenoviral vectors, and naïve CD8 cells
Project description:Metaproteomic analysis of paired fresh, frozen and swab-collected/preservation medium-stored feces from four healthy human subjects
Project description:Nitrogen (N) is an essential macronutrient for agricultural production, and its excessive use causes not only economic but also environmental damage. However, improving nitrogen use efficiency (NUE) remains a complex task for achieving more productive crops under conditions of limited nitrogen availability. To the best of our knowledge, this is the first study aiming to integrate the morphophysiological responses and proteomic profiles of leaves and roots of popcorn (Zea mays everta). For this, two inbred lines contrasting for NUE, i.e., P2 (high NUE) and L80 (low NUE), were cultivated under high (100% of N supply) and low (10% of N supply) nitrogen conditions. Morphological and physiological traiits such as photochemical quenching (qP), non-photochemical quenching (NPQ), quantum yield of photosystem II (ΦPSII), and potential photosynthesis (Apot) were evaluated. P2 showed more pronounced vegetative growth under low N, as well as higher values of qP, NPQ, and ΦPSII. Comparative proteomic analysis of the leaves identified 215 differentially accumulated proteins (DAPs) in P2 and 168 DAPs in L80, while in roots, 127 DAPs were observed in P2 and 172 in L80. In leaves, DAPs involved in the response to oxidative stress, energy metabolism, and photosynthesis represented the main differences between P2 and L80. In roots, DAPs involved in nitrate transport, ammonium assimilation, and amino acid metabolism seem to have contributed to the improved NUE in P2. This study provides valuable insights into the molecular mechanisms underlying NUE and opens avenues for molecular breeding aimed at selecting superior genotypes for the development of a more sustainable agriculture.
Project description:Objectives: Our work focuses on the responses of Solanaceous plants to viruses that cause economically important diseases in tree fruits. Using mock inoculated leaf tissue as a reference, we plan to compare the gene expression profiles of Nicotiana Benthamiana plants infected with one of three viruses; Plum Pox Potyvirus (PPV), Tomato Ringspot Nepovirus (ToRSV), and Prunus Nectrotic Ringspot Nepovirus (PNRSV). Our goals are as follows: (1) Identify genes that are induced/repressed in response to individual viruses. (2) Identify genes that are induced/repressed in response to all 3 viruses. (3) Compare results to existing potato array data to look for similarities in responses to other pathogens. Experimental Design: Nicotiana benthamiana plants were inoculated with one of three viruses: PPV, ToRSV, or PNRSV. 3 week old plants were inoculated by rubbing virus infected plant sap onto leaves dusted with carborundum. Control plants were mock inoculated using sap from healthy plants. All plants were maintained in a growth chamber at 22C for 18 days. 8 plants were inoculated with each virus or mock inoculated. This experiment was repeated twice. 4 biological replicates derived from 2 virus infected plants from each replica experiment (4 plants) are to be used for hybridizations. RNA from all mock inoculated plants was similarly pooled to create 4 biological replicates. Each replicate control will serve as a universal reference sample that is to be hybridized pair wise with each of the three virus infected samples. RNA extraction: After 18 days, un-inoculated leaves displaying clear symptoms were harvested and immediately frozen in liquid N2. Total RNA was purified using Trizol according to TIGRs listed protocol. RNA was subsequently treated with Turbo DNA-free RNase (Ambion cat#1907). Finally, total RNA was further purified on RNeasy columns (Qiagen) according to manufacturer’s instructions and quantified using a Nanodrop spectrophotometer. Keywords: Reference design 23 hybs total
Project description:A gradient cell elongation with maximum in the lower side of pulvini and minimum in the upper side of pulvini pushes a maize stem upwards from a horizontal to a vertical position during gravitropsim. A differentiated gene expression between lower and upper pulvini was examined at 1 h, 6 and 24 h. Gene expression levels were compared in control (not bending), lower and upper (bending) pulvini. The samples were harvested at 1 h, 6 h and 24 h gravitropsim and total RNA were extracted using for microarray experiment.