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1.
EMBnet J ; 292024.
Article in English | MEDLINE | ID: mdl-38845752

ABSTRACT

Breast milk, often referred to as "liquid gold," is a complex biofluid that provides essential nutrients, immune factors, and developmental cues for newborns. Recent advancements in the field of exosome research have shed light on the critical role of exosomes in breast milk. Exosomes are nanosized vesicles that carry bioactive molecules, including proteins, lipids, nucleic acids, and miRNAs. These tiny messengers play a vital role in intercellular communication and are now being recognized as key players in infant health and development. This paper explores the emerging field of milk exosomics, emphasizing the potential of exosome fingerprinting to uncover valuable insights into the composition and function of breast milk. By deciphering the exosomal cargo, we can gain a deeper understanding of how breast milk influences neonatal health and may even pave the way for personalized nutrition strategies.

2.
Diagnostics (Basel) ; 13(17)2023 Aug 24.
Article in English | MEDLINE | ID: mdl-37685286

ABSTRACT

Acute lymphoblastic leukemia (ALL) is the most common cancer in children and one of the success stories in cancer therapeutics. Risk-directed therapy based on clinical, biologic and genetic features has played a significant role in this accomplishment. Despite the observed improvement in survival rates, leukemia remains one of the leading causes of cancer-related deaths. Implementation of next-generation genomic and transcriptomic sequencing tools has illustrated the genomic landscape of ALL. However, the underlying dynamic changes at protein level still remain a challenge. Proteomics is a cutting-edge technology aimed at deciphering the mechanisms, pathways, and the degree to which the proteome impacts leukemia subtypes. Advances in mass spectrometry enable high-throughput collection of global proteomic profiles, representing an opportunity to unveil new biological markers and druggable targets. The purpose of this narrative review article is to provide a comprehensive overview of studies that have utilized applications of proteomics in an attempt to gain insight into the pathogenesis and identification of biomarkers in childhood ALL.

3.
Cancers (Basel) ; 15(15)2023 Jul 31.
Article in English | MEDLINE | ID: mdl-37568720

ABSTRACT

In most lymphomas, p53 signaling pathway is inactivated by various mechanisms independent to p53 gene mutations or deletions. In many cases, p53 function is largely regulated by alterations in the protein abundance levels by the action of E3 ubiquitin-protein ligase MDM2, targeting p53 to proteasome-mediated degradation. In the present study, an integrating transcriptomics and proteomics analysis was employed to investigate the effect of p53 activation by a small-molecule MDM2-antagonist, nutlin-3a, on three lymphoma cell models following p53 activation. Our analysis revealed a system-wide nutlin-3a-associated effect in all examined lymphoma types, identifying in total of 4037 differentially affected proteins involved in a plethora of pathways, with significant heterogeneity among lymphomas. Our findings include known p53-targets and novel p53 activation effects, involving transcription, translation, or degradation of protein components of pathways, such as a decrease in key members of PI3K/mTOR pathway, heat-shock response, and glycolysis, and an increase in key members of oxidative phoshosphorylation, autophagy and mitochondrial translation. Combined inhibition of HSP90 or PI3K/mTOR pathway with nutlin-3a-mediated p53-activation enhanced the apoptotic effects suggesting a promising strategy against human lymphomas. Integrated omic profiling after p53 activation offered novel insights on the regulatory role specific proteins and pathways may have in lymphomagenesis.

4.
Res Vet Sci ; 162: 104959, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37480717

ABSTRACT

Canine degenerative myelopathy (CDM) is a late-onset fatal disorder associated with a point mutation of the superoxide dismutase 1 (SOD1) gene (c.118G > A). The purpose of this study was to determine the genotype and allele frequencies of this mutation in 108 dogs, mainly in Belgian Malinois and German Shepherd dogs with (CDM-affected group) and without CDM clinical symptoms (control group) in Greece. Genotyping of the c.118G > A mutation was possible by Sanger sequencing and PCR-RFLP. The observed genotype frequencies for the control group were 89.4% for the homozygous (G/G), 9.6% for the heterozygous (A/G), and 0.96% for the homozygous mutant (A/A) allele. The mutant allele was not common in the Belgian Malinois dogs (allele frequency = 0.029), but quite common in the German Shepherd dogs (allele frequency = 0.138). In the CDM affected group, all 4 dogs were homozygous for the mutant allele. These frequencies were close to those expected, indicating no significant departure from Hardy-Weinberg equilibrium. A strong but not statistically significant association between the mutant allele and CDM was observed. A previously identified deletion upstream of the mutation of interest was found at a high frequency (0.361) in the population.


Subject(s)
Dog Diseases , Spinal Cord Diseases , Dogs , Animals , Superoxide Dismutase-1/genetics , Greece/epidemiology , Prevalence , Alleles , Spinal Cord Diseases/epidemiology , Spinal Cord Diseases/genetics , Spinal Cord Diseases/veterinary , Dog Diseases/epidemiology , Dog Diseases/genetics
5.
Life (Basel) ; 13(1)2023 Jan 06.
Article in English | MEDLINE | ID: mdl-36676122

ABSTRACT

(1) Background: Compelling evidence shows that dietary patterns can slow the rate of cognitive decline, suggesting diet is a promising preventive measure against dementia. (2) Objective: This systematic review summarizes the evidence of three dietary patterns, the Mediterranean diet, the ketogenic diet and the MIND diet, for the prevention of cognitive decline. (3) Methods: A systematic search was conducted in major electronic databases (PubMed, ScienceDirect and Web of Science) up until 31 January 2022, using the key search terms "Mediterranean diet", "ketogenic diet", "MIND diet", "dementia", "cognition" and "aging". A statistical analysis was performed using RoB 2 and the Jadad scale to assess the risk of bias and methodological quality in randomized controlled trials. (4) Results: Only RCTs were included in this study; there were eleven studies (n = 2609 participants) of the Mediterranean diet, seven studies (n = 313) of the ketogenic diet and one study (n = 37) of the MIND diet. The participants' cognitive statuses were normal in seven studies, ten studies included patients with mild cognitive impairments and two studies included Alzheimer's disease patients. (5) Conclusion: All three dietary interventions have been shown to slow the rate of cognitive decline in the included studies. The Mediterranean diet was shown to be beneficial for global cognition after 10 weeks of adherence, the ketogenic diet had a beneficial effect for patients with diabetes mellitus and improved verbal recognition, while the MIND diet showed benefits in obese patients, improving working memory, verbal recognition, memory and attention.

6.
Front Mol Biosci ; 9: 805541, 2022.
Article in English | MEDLINE | ID: mdl-35187080

ABSTRACT

Heterogeneity of the main ribosomal composition represents an emerging, yet debatable, mechanism of gene expression regulation with a purported role in ribosomopathies, a group of disorders caused by mutations in ribosomal protein genes (RPs). Ribosomopathies, mysteriously relate with tissue-specific symptoms (mainly anemia and cancer predisposition), despite the ubiquitous expression and necessity of the associated RPs. An outstanding question that may shed light into disease pathogenicity and provide potential pharmacological interventions, is whether and how the ribosomal composition is modified during, the highly affected by RP mutations, process of erythroid differentiation. To address this issue, we analyzed ribosome stoichiometry using an established model of erythroid differentiation, through sucrose gradient ultracentrifugation and quantitative proteomics. We found that differentiation associates with an extensive reprogramming of the overall ribosomal levels, characterized by an increase in monosomes and a decrease in polysomes. However, by calculating a stoichiometry score for each independent ribosomal protein, we found that the main ribosomal architecture remained invariable between immature and differentiated cells. In total, none of the 78 Ribosomal Proteins (RPs- 74 core RPs, Rack1, Fau and 2 paralogs) detected was statistically different between the samples. This data was further verified through antibody-mediated quantification of 6 representative RPs. Moreover, bioinformatic analysis of whole cell proteomic data derived out of 4 additional models of erythropoiesis revealed that RPs were co-regulated across these cell types, too. In conclusion, ribosomes maintain an invariant protein stoichiometry during differentiation, thus excluding ribosome heterogeneity from a potential mechanism of toxicity in ribosomopathies and other erythroid disorders.

7.
Materials (Basel) ; 15(2)2022 Jan 12.
Article in English | MEDLINE | ID: mdl-35057267

ABSTRACT

Raman spectroscopy is a well-defined spectroscopic technique sensitive to the molecular vibrations of materials, since it provides fingerprint-like information regarding the molecular structure of the analyzed samples. It has been extensively used for non-destructive and label-free cell characterization, particularly in the qualitative and quantitative estimation of amino acids, lipids, nucleic acids, and carbohydrates. Lymphoma cell classification is a crucial task for accurate and prompt lymphoma diagnosis, prognosis, and treatment. Currently, it is mostly based on limited information and requires costly and time-consuming approaches. In this work, we are proposing a fast characterization and differentiation methodology of lymphoma cell subtypes based on Raman spectroscopy. The study was performed in the temperature range of 15-37 °C to identify the best cell measurement conditions. The proposed methodology is fast, accurate, and requires minimal sample preparation, resulting in a potentially promising, non-invasive strategy for early and accurate cell lymphoma characterization.

8.
BMC Genomics ; 23(1): 75, 2022 Jan 24.
Article in English | MEDLINE | ID: mdl-35073840

ABSTRACT

BACKGROUND: Caterpillars from the insect order Lepidoptera are some of the most widespread and destructive agricultural pests. Most of their impact is at the larval stage, where the midgut epithelium mediates the digestion and absorption of an astonishing amount of food. Although this tissue has been the subject of frequent investigation in Lepidoptera, a comprehensive expression atlas has yet to be generated. RESULTS: Here, we perform RNA-sequencing and proteomics on the gut of the polyphagous pest Helicoverpa armigera across, life stages, diet types, and compartments of the anterior-posterior axis. A striking relationship between the structural homology and expression pattern of a group of sugar transporters was observed in the early larval stages. Further comparisons were made among the spatial compartments of the midgut, which suggested a putative role for vATPases and SLC9 transporters in the generation of alkaline conditions in the H. armigera midgut. CONCLUSIONS: This comprehensive resource will aid the scientific community in understanding lepidopteran gut physiology in unprecedented resolution. It is hoped that this study advances the understanding of the lepidopteran midgut and also facilitates functional work in this field.


Subject(s)
Moths , Animals , Digestive System , Hydrogen-Ion Concentration , Larva , Nutrients
9.
Cancers (Basel) ; 13(14)2021 Jul 06.
Article in English | MEDLINE | ID: mdl-34298607

ABSTRACT

CLL is a hematological malignancy considered as the most frequent lymphoproliferative disease in the western world. It is characterized by high molecular heterogeneity and despite the available therapeutic options, there are many patient subgroups showing the insufficient effectiveness of disease treatment. The challenge is to investigate the individual molecular characteristics and heterogeneity of these patients. Proteomics analysis is a powerful approach that monitors the constant state of flux operators of genetic information and can unravel the proteome heterogeneity and rewiring into protein pathways in CLL patients. This review essences all the available proteomics studies in CLL and suggests the way these studies can be exploited to find effective therapeutic options combined with drug repurposing approaches. Drug repurposing utilizes all the existing knowledge of the safety and efficacy of FDA-approved or investigational drugs and anticipates drug alignment to crucial CLL therapeutic targets, leading to a better disease outcome. The drug repurposing studies in CLL are also discussed in this review. The next goal involves the integration of proteomics-based drug repurposing in precision medicine, as well as the application of this procedure into clinical practice to predict the most appropriate drugs combination that could ensure therapy and the long-term survival of each CLL patient.

10.
J Cell Physiol ; 236(2): 1529-1544, 2021 02.
Article in English | MEDLINE | ID: mdl-32749687

ABSTRACT

Exosome selectivity mechanisms underlying exosome-target cell interactions and the specific traits affecting their capability to communicate still remain unclear. Moreover, the capacity of exosomes to efficiently deliver their molecular cargos intracellularly needs precise investigation towards establishing functional exosome-based delivery platforms exploitable in the clinical practice. The current study focuses on: (a) exosome production from normal MRC-5 and Vero cells growing in culture, (b) physicochemical characterization by dynamic light scattering (DLS) and cryo-transmission electron microscopy; (c) cellular uptake studies of rhodamine-labeled exosomes in normal and cancer cells, providing to exosomes either "autologous" or "heterologous" cellular delivery environments; and (d) loading exogenous Alexa Fluor 488-labeled siRNA into exosomes for the assessment of their delivering capacity by immunofluorescence in a panel of recipient cells. The data obtained thus far indicate that MRC-5 and Vero exosomes, indeed exhibit an interesting delivering profile, as promising "bio-shuttles," being pharmacologically exploitable in the context of theranostic applications.


Subject(s)
Drug Delivery Systems , Exosomes/chemistry , MicroRNAs/therapeutic use , RNA, Small Interfering/therapeutic use , Animals , Cell Communication/genetics , Cell Line, Tumor , Chlorocebus aethiops , Cryoelectron Microscopy , Exosomes/genetics , Humans , MicroRNAs/chemistry , RNA, Small Interfering/chemistry , Vero Cells
11.
Hormones (Athens) ; 19(3): 369-376, 2020 Sep.
Article in English | MEDLINE | ID: mdl-32405930

ABSTRACT

PURPOSE: The salivary amylase gene (AMY1) copy number variation (CNV) is increased as a human adaptation to starch-enriched nutritional patterns. The purpose of this study was to evaluate the relationship between AMY1 CNV, dietary starch consumption, and anthropometric indices among a known population with elevated cardiovascular risk, being end-stage renal disease (ESRD) patients. METHODS: A total of 43 ESRD patients were recruited based on the following inclusion criteria: being (1) adults, (2) on hemodialysis for more than 3 months, (3) able to communicate effectively, and (4) willing to participate. Anthropometric measurements were performed, dietary intake was recorded via food-frequency questionnaires, and AMY1 CNV was quantified in blood samples DNA via real-time PCR. RESULTS: Median AMY1 CNV was 4.0 (2.0-17.0). A total of 21 patients had an even, and 22 had an odd AMY1 copy number (CN). Independent samples t tests revealed that AMY1-odd diploid CN is associated with increased body weight, waist and hip circumferences, and fat mass compared to the respective even diploid CN carrier group. No differences were observed for BMI or nutritional intake. Multiple regression analysis revealed that AMY1-odd diploid CN was positively associated with increased hip circumference (ß = 7.87, 95% CI = 0.34 to 15.39) and absolute fat mass (ß = 6.66, 95% CI = 0.98 to 12.34); however, after applying the Bonferroni correction for multiplicity, all regression analyses lost their significance. CONCLUSIONS: AMY1-odd diploid CN appears to be associated with selected adiposity variables among hemodialysis patients. However, more research is needed to verify this finding in this population with known increased cardiovascular risk.


Subject(s)
Adipose Tissue , Body Weights and Measures , Eating , Kidney Failure, Chronic/genetics , Salivary alpha-Amylases/genetics , Starch , Adult , DNA Copy Number Variations , Diploidy , Female , Humans , Male , Middle Aged , Renal Dialysis
12.
Nat Commun ; 11(1): 42, 2020 01 02.
Article in English | MEDLINE | ID: mdl-31896748

ABSTRACT

DNA damage and metabolic disorders are intimately linked with premature disease onset but the underlying mechanisms remain poorly understood. Here, we show that persistent DNA damage accumulation in tissue-infiltrating macrophages carrying an ERCC1-XPF DNA repair defect (Er1F/-) triggers Golgi dispersal, dilation of endoplasmic reticulum, autophagy and exosome biogenesis leading to the secretion of extracellular vesicles (EVs) in vivo and ex vivo. Macrophage-derived EVs accumulate in Er1F/- animal sera and are secreted in macrophage media after DNA damage. The Er1F/- EV cargo is taken up by recipient cells leading to an increase in insulin-independent glucose transporter levels, enhanced cellular glucose uptake, higher cellular oxygen consumption rate and greater tolerance to glucose challenge in mice. We find that high glucose in EV-targeted cells triggers pro-inflammatory stimuli via mTOR activation. This, in turn, establishes chronic inflammation and tissue pathology in mice with important ramifications for DNA repair-deficient, progeroid syndromes and aging.


Subject(s)
DNA Damage/physiology , Exosomes/metabolism , Macrophages/cytology , Animals , DNA Repair , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Endonucleases/genetics , Endonucleases/metabolism , Exosomes/pathology , Gene Expression Regulation , Glucose/metabolism , Glucose Transporter Type 1/metabolism , Inflammation/genetics , Inflammation/metabolism , Inflammation/pathology , Macrophages/metabolism , Male , Mice, Transgenic , Neuropeptides/genetics , Neuropeptides/metabolism , TOR Serine-Threonine Kinases/metabolism , rab GTP-Binding Proteins/genetics , rab GTP-Binding Proteins/metabolism , rac1 GTP-Binding Protein/genetics , rac1 GTP-Binding Protein/metabolism
13.
NAR Genom Bioinform ; 2(1): lqaa005, 2020 Mar.
Article in English | MEDLINE | ID: mdl-33575553

ABSTRACT

The in-depth study of protein-protein interactions (PPIs) is of key importance for understanding how cells operate. Therefore, in the past few years, many experimental as well as computational approaches have been developed for the identification and discovery of such interactions. Here, we present UniReD, a user-friendly, computational prediction tool which analyses biomedical literature in order to extract known protein associations and suggest undocumented ones. As a proof of concept, we demonstrate its usefulness by experimentally validating six predicted interactions and by benchmarking it against public databases of experimentally validated PPIs succeeding a high coverage. We believe that UniReD can become an important and intuitive resource for experimental biologists in their quest for finding novel associations within a protein network and a useful tool to complement experimental approaches (e.g. mass spectrometry) by producing sorted lists of candidate proteins for further experimental validation. UniReD is available at http://bioinformatics.med.uoc.gr/unired/.

15.
Proc Biol Sci ; 286(1907): 20191091, 2019 07 24.
Article in English | MEDLINE | ID: mdl-31311476

ABSTRACT

Malaria incidence has halved since the year 2000, with 80% of the reduction attributable to the use of insecticides. However, insecticide resistance is now widespread, is rapidly increasing in spectrum and intensity across Africa, and may be contributing to the increase of malaria incidence in 2018. The role of detoxification enzymes and target site mutations has been documented in the major malaria vector Anopheles gambiae; however, the emergence of striking resistant phenotypes suggests the occurrence of additional mechanisms. By comparing legs, the most relevant insect tissue for insecticide uptake, we show that resistant mosquitoes largely remodel their leg cuticles via enhanced deposition of cuticular proteins and chitin, corroborating a leg-thickening phenotype. Moreover, we show that resistant female mosquitoes seal their leg cuticles with higher total and different relative amounts of cuticular hydrocarbons, compared with susceptible ones. The structural and functional alterations in Anopheles female mosquito legs are associated with a reduced uptake of insecticides, substantially contributing to the resistance phenotype.


Subject(s)
Anopheles/physiology , Extremities/physiology , Insecticide Resistance , Insecticides/pharmacology , Mosquito Vectors/physiology , Animals , Anopheles/ultrastructure , Female , Lipidomics , Malaria/transmission , Male , Microscopy, Electron, Transmission , Mosquito Vectors/ultrastructure , Proteome , Proteomics
16.
Data Brief ; 25: 104210, 2019 Aug.
Article in English | MEDLINE | ID: mdl-31334320

ABSTRACT

SRPK1 is an evolutionary conserved protein kinase that specifically phosphorylates its substrates at serine residues located within arginine-serine-rich (RS) domains. We have previously reported the existence of a second less abundant isoform in humans, SRPK1a, which is formed from alternative splicing of the SRPK1 gene and contains an insertion of 171 amino acids at its N-terminal domain (Nikolakaki et al., 2001). In the NCBI database SRPK1a is annotated as a related to SRPK1-mRNA sequence coding for protein CAC39299.1. Here, we present data on the conservation of the extra sequence of SRPK1a in mammals. Furthermore, the retrieved sequences were comparatively analyzed and data on their evolutionary origin and relationships are also presented.

17.
Gene ; 710: 333-340, 2019 Aug 20.
Article in English | MEDLINE | ID: mdl-31202904

ABSTRACT

Gene promoter methylation is a common epigenetic event, taking place in the early phase of tumorigenesis, which has a great potential as a diagnostic and prognostic cancer biomarker. In this umbrella review, we provide an overview on the association between gene-promoter methylation of protein-coding genes and cancer risk based on currently available meta-analyses data on gene promoter methylation. We searched MEDLINE via PubMed and the Cochrane Database of Systematic Reviews for meta-analyses that examine the association between gene-promoter methylation and cancer, published until January 2019 in English. We used AMSTAR to assess the quality of the included studies and applied a set of pre-specified criteria to evaluate the magnitude of each association. We provide a comprehensive overview of 80 unique combinations between 22 different genes and 18 cancer outcomes, all of which indicated a positive association between promoter hypermethylation and cancer. In total, the 70 meta-analyses produced significant results under a random-effects model with odds ratios that ranged from 1.94 to 26.60, with the summary effect being in favor of the unmethylated group in all cases. Three of the strong evidence associations involve RASSF1 methylation on bladder cancer risk (OR = 18.46; 95% CI: 12.69-26.85; I2 = 0%), MGMT methylation on NSCLC (OR = 4.25; 95% CI: 2.83-6.38; I2 = 22.4%) and RARB methylation on prostate cancer (OR = 6.87; 95% CI: 4.68-10.08; I2 = 0%). Meta-analyses showed a moderate quality, AMSTAR score ranging from 4 to 9 (Mdn = 8; IQR: 7.0 to 8.0). As primary studies and meta-analyses on the subject accumulate, more genetic loci may be found to be highly associated with specific cancer types and hence the biomarker sets will become wider.


Subject(s)
DNA Methylation , DNA Modification Methylases/genetics , DNA Repair Enzymes/genetics , Neoplasms/genetics , Receptors, Retinoic Acid/genetics , Tumor Suppressor Proteins/genetics , Biomarkers, Tumor/genetics , Carcinoma, Non-Small-Cell Lung/genetics , Epigenesis, Genetic , Female , Genetic Predisposition to Disease , Humans , Lung Neoplasms/genetics , Male , Meta-Analysis as Topic , Odds Ratio , Promoter Regions, Genetic , Prostatic Neoplasms/genetics , Urinary Bladder Neoplasms/genetics
18.
Neuropharmacology ; 144: 193-207, 2019 01.
Article in English | MEDLINE | ID: mdl-30366002

ABSTRACT

Schizophrenia is a debilitating disorder with complex and unclarified etiological factors. Sex differences have been observed in humans but animal models have only focused on male subjects. In this study, we report the establishment of the neurodevelopmental MAM model of schizophrenia in mice and compare the schizotypic-like characteristics and cognitive functions in both sexes. Pregnant mice were injected with methylazoxymethanol acetate (MAM) or saline on gestational day (GD) 16 (MAM-16) or 17 (MAM-17). Female MAM-16, but not MAM-17 treated mice exhibited enhanced hyperlocomotion after acute MK-801 administration, compared to saline treated mice. Male MAM-16, but not MAM-17, treated mice showed reduced pre-pulse inhibition of the acoustic startle reflex. Both male and female MAM-16 and MAM-17 treated mice exhibited smaller hippocampal (HPC) size and thinning of the prefrontal cortex (PFC), but only male MAM-16 treated mice showed decreased parvalbumin expression in HPC and PFC. Similarly, both male and female MAM-16 treated mice displayed impaired contextual fear memory and significantly reduced long-term potentiation (LTP) in the HPC CA1 synapses. However, male, but not female, MAM-16 treated mice exhibited deficits in the delayed alternation task and LTP in layer II PFC synapses. Proteomic analyses of PFC lysates further showed significant MAM- and sex-dependent differences in protein expression regulation. Our results demonstrate that while both male and female mice, prenatally exposed to MAM on GD16, display several core schizophrenia-like deficits and impairments in the hippocampus, only male MAM-treated mice have PFCdependent cognitive deficits.


Subject(s)
Disease Models, Animal , Hippocampus/physiopathology , Prefrontal Cortex/physiopathology , Schizophrenia/physiopathology , Sex Characteristics , Animals , Auditory Perception/physiology , Fear/physiology , Female , Hippocampus/pathology , Long-Term Potentiation/physiology , Male , Memory/physiology , Methylazoxymethanol Acetate , Mice , Mice, Inbred C57BL , Prefrontal Cortex/pathology , Pregnancy , Prenatal Exposure Delayed Effects , Prepulse Inhibition/physiology , Proteome , Reflex, Startle/physiology , Schizophrenia/pathology , Schizophrenic Psychology
19.
mBio ; 9(4)2018 07 31.
Article in English | MEDLINE | ID: mdl-30065089

ABSTRACT

Many plant-pathogenic bacteria of considerable economic importance rely on type III secretion systems (T3SSs) of the Hrc-Hrp 1 family to subvert their plant hosts. T3SS gene expression is regulated through the HrpG and HrpV proteins, while secretion is controlled by the gatekeeper HrpJ. A link between the two mechanisms was so far unknown. Here, we show that a mechanistic coupling exists between the expression and secretion cascades through the direct binding of the HrpG/HrpV heterodimer, acting as a T3SS chaperone, to HrpJ. The ternary complex is docked to the cytoplasmic side of the inner bacterial membrane and orchestrates intermediate substrate secretion, without affecting early substrate secretion. The anchoring of the ternary complex to the membranes potentially keeps HrpG/HrpV away from DNA. In their multiple roles as transcriptional regulators and gatekeeper chaperones, HrpV/HrpG provide along with HrpJ potentially attractive targets for antibacterial strategies.IMPORTANCE On the basis of scientific/economic importance, Pseudomonas syringae and Erwinia amylovora are considered among the top 10 plant-pathogenic bacteria in molecular plant pathology. Both employ type III secretion systems (T3SSs) of the Hrc-Hrp 1 family to subvert their plant hosts. For Hrc-Hrp 1, no functional link was known between the key processes of T3SS gene expression and secretion. Here, we show that a mechanistic coupling exists between expression and secretion cascades, through formation of a ternary complex involving the T3SS proteins HrpG, HrpV, and HrpJ. Our results highlight the functional and structural properties of a hitherto-unknown complex which orchestrates intermediate T3SS substrate secretion and may lead to better pathogen control through novel targets for antibacterial strategies.


Subject(s)
Erwinia amylovora/metabolism , Gene Expression , Protein Transport , Pseudomonas syringae/metabolism , Regulatory Sequences, Nucleic Acid , Transcription, Genetic , Type III Secretion Systems/metabolism , Erwinia amylovora/genetics , Pseudomonas syringae/genetics , Type III Secretion Systems/genetics
20.
Nucleic Acids Res ; 45(W1): W300-W306, 2017 07 03.
Article in English | MEDLINE | ID: mdl-28520987

ABSTRACT

Profiling of proteome dynamics is crucial for understanding cellular behavior in response to intrinsic and extrinsic stimuli and maintenance of homeostasis. Over the last 20 years, mass spectrometry (MS) has emerged as the most powerful tool for large-scale identification and characterization of proteins. Bottom-up proteomics, the most common MS-based proteomics approach, has always been challenging in terms of data management, processing, analysis and visualization, with modern instruments capable of producing several gigabytes of data out of a single experiment. Here, we present ProteoSign, a freely available web application, dedicated in allowing users to perform proteomics differential expression/abundance analysis in a user-friendly and self-explanatory way. Although several non-commercial standalone tools have been developed for post-quantification statistical analysis of proteomics data, most of them are not end-user appealing as they often require very stringent installation of programming environments, third-party software packages and sometimes further scripting or computer programming. To avoid this bottleneck, we have developed a user-friendly software platform accessible via a web interface in order to enable proteomics laboratories and core facilities to statistically analyse quantitative proteomics data sets in a resource-efficient manner. ProteoSign is available at http://bioinformatics.med.uoc.gr/ProteoSign and the source code at https://github.com/yorgodillo/ProteoSign.


Subject(s)
Proteomics/methods , Software , Data Interpretation, Statistical , Internet , Mass Spectrometry
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