Giovanni Renzone

Duke University Medical Center, Durham, North Carolina, United States

Are you Giovanni Renzone?

Claim your profile

Publications (60)200.92 Total impact

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Background: The filamentous actinomycete Microbispora ATCC-PTA-5024 produces the lantibiotic NAI-107, which is an antibiotic peptide effective against multidrug-resistant Gram-positive bacteria. In actinomycetes, antibiotic production is often associated with a physiological differentiation program controlled by a complex regulatory and metabolic network that may be elucidated by the integration of genomic, proteomic and bioinformatic tools. Accordingly, an extensive evaluation of the proteomic changes associated with NAI-107 production was performed on Microbispora ATCC-PTA-5024 by combining two-dimensional difference in gel electrophoresis, mass spectrometry and gene ontology approaches. Results: Microbispora ATCC-PTA-5024 cultivations in a complex medium were characterized by stages of biomass accumulation (A) followed by biomass yield decline (D). NAI-107 production started at 90 h (A stage), reached a maximum at 140 h (D stage) and decreased thereafter. To reveal patterns of differentially represented proteins associated with NAI-107 production onset and maintenance, differential proteomic analyses were carried-out on biomass samples collected: i) before (66 h) and during (90 h) NAI-107 production at A stage; ii) during three time-points (117, 140, and 162 h) at D stage characterized by different profiles of NAI-107 yield accumulation (117 and 140 h) and decrement (162 h). Regulatory, metabolic and unknown-function proteins, were identified and functionally clustered, revealing that nutritional signals, regulatory cascades and primary metabolism shift-down trigger the accumulation of protein components involved in nitrogen and phosphate metabolism, cell wall biosynthesis/maturation, lipid metabolism, osmotic stress response, multi-drug resistance, and NAI-107 transport. The stimulating role on physiological differentiation of a TetR-like regulator, originally identified in this study, was confirmed by the construction of an over-expressing strain. Finally, the possible role of cellular response to membrane stability alterations and of multi-drug resistance ABC transporters as additional self-resistance mechanisms toward the lantibiotic was confirmed by proteomic and confocal microscopy experiments on a Microbispora ATCC-PTA-5024 lantibiotic-null producer strain which was exposed to an externally-added amount of NAI-107 during growth. Conclusion: This study provides a net contribution to the elucidation of the regulatory, metabolic and molecular patterns controlling physiological differentiation in Microbispora ATCC-PTA-5024, supporting the relevance of proteomics in revealing protein players of antibiotic biosynthesis in actinomycetes.
    Full-text · Article · Dec 2016 · BMC Genomics
  • Source
    [Show description] [Hide description]
    DESCRIPTION: This work unraveled the cellular function of small ORF SCO2038 as key protein in modulation of tryptophan biosynthetic pathway by a new mechanism based on protein-protein interaction.
    Full-text · Research · Oct 2015
  • [Show abstract] [Hide abstract]
    ABSTRACT: The molecular mechanisms regulating tryptophan biosynthesis in actinomycetes are poorly understood; similarly, the possible roles of tryptophan in the differentiation program of microorganism life-cycle are still underexplored. To unveil the possible regulatory effect of this amino acid on gene expression, an integrated study based on quantitative teverse transcription-PCR (qRT-PCR) and proteomic approaches was performed on the actinomycete model Streptomyces coelicolor. Comparative analyses on the microorganism growth in a minimal medium with or without tryptophan supplementation showed that biosynthetic trp gene expression in S. coelicolor is not subjected to a negative regulation by the presence of the end product. Conversely, tryptophan specifically induces the transcription of trp genes present in the biosynthetic gene cluster of the calcium-dependent antibiotic (CDA), a lipopeptide containing D- and L-tryptophan residues. In addition, tryptophan stimulates the transcription of the CDA gene cluster regulator cdaR and, coherently, CDA production. Surprisingly, tryptophan also promotes the production of actinorhodin, another antibiotic that does not contain this amino acid in its structure. Combined 2D-DIGE and nano liquid chromatography electrospray linear ion trap tandem mass spectrometry (LC-ESI-LIT-MS/MS) analyses revealed that tryptophan exerts a growth-stage-dependent global effect on S. coelicolor proteome, stimulating anabolic pathways and promoting the accumulation of key factors associated with morphological and physiological differentiation at the late growth stages. Phenotypic observations by scanning electron microscopy and spore production assays demonstrated an increased sporulation in the presence of tryptophan. Transcriptional analysis of catabolic genes kynA and kynB suggested that the actinomycete also uses tryptophan as a carbon and nitrogen source. In conclusion, this study originally provides the molecular basis underlying the stimulatory effect of tryptophan on the production of antibiotics and morphological development program of this actinomycete.
    No preview · Article · Oct 2015 · Applied Microbiology and Biotechnology
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Introduction Dioxin-like (DL) compounds are persistent and highly toxic organic pollutants. Due to their high lipophilicity, they accumulate along the food chain and contaminate animal products, which are by far the most important non-professional source for humans. Official methods for DL-compounds detection in foodstuffs are expensive and time consuming. Thus, there is a demand for faster and cost effective screening methods based on the identification of biomarkers of exposure in easily collectable samples. Proteomic techniques are of growing interest in this respect (1). Aim of this study was to investigate the changes in low molecular weight (MW) protein profile in serum samples from heifers accidentally exposed to DL-PCBs and then subjected to a decontamination protocol. Materials and Methods Eight one-year-old DL-PCB accidentally exposed heifers were reared in a non-contaminated experimental facility under controlled conditions for six months. Four serum and fat samples were collected from each animal at two-month intervals (A, B, C, D). DL-PCB content was assayed in fat using GC-HR-MS with a validated method. Serum samples were extracted and analyzed in the 2-20 kDa range using a linear MALDI-TOF. Mass spectra were statistically processed using ClinProTools and analyzed by Wilcoxon and Kruskal-Wallis test. Peak identification was performed through separation by liquid chromatography, structure characterization with a MALDI-TOF/TOF-MS and/or nanoLC-ESI-linear ion trap (LIT)-MS/MS, and analysis using MASCOT search engine. Results and Discussion Exposed heifers displayed very high DL-PCB TEQ values (26.22 ± 2.17 pg/g fat) in sampling A, undergoing a rapid decontamination in the following two months (B), showing values complying with legal limits in C and D samples. Protein profiling revealed 48 statistically significant peaks (P<0.05), which were selected to be identified according to their increasing or decreasing intensity among the 4 samplings. Fibrinogen β-chain, apolipoprotein A-II, and apolipoprotein C-III raised throughout the decontamination, whereas apolipoprotein C-II short-form, Complement C4, amyloid A-4 protein, and hemoglobin subunit-α declined. Interestingly, similar changes in serum apolipoprotein and Complement C4 have been reported in TCDD-exposed humans (2), while amyloid A, a known inflammatory marker, is associated with PAH exposure (3). Further studies are needed to build a predictive model able to identify contaminated animals.
    Full-text · Conference Paper · Jul 2015
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Coronary artery disease (CAD) is the leading cause of death in western countries, and its association with lower extremity peripheral artery disease (LE-PAD) represents an independent predictor of worse outcome. However, the molecular mechanisms underlying these effects are currently unknown. To investigate these processes, we used in vitro approaches and several mouse models: I) unilateral limb ischemia by left common femoral artery ligation (PI, n=38); II) myocardial infarction by permanent ligation of the left descending coronary artery (MI, n=40); III) MI after five weeks of limb ischemia (PI+MI, n=44); IV) sham operation (SHAM, n=20). Compared to MI, PI+MI hearts were characterized by a significant increase in cardiomyocyte apoptosis, larger infarct areas and decreased cardiac function. By using a proteomic approach, we identified a ≅8 kDa circulating peptide, Dermcidin (DCD), secreted by ischemic skeletal muscles, enhancing cardiomyocytes apoptosis under hypoxic conditions and infarct size after permanent coronary artery ligation. siRNA interference experiments to reduce DCD circulating levels significantly reduced infarct size and ameliorated cardiac function after MI. Our data demonstrate that chronic limb ischemia activates detrimental pathways in the ischemic heart through humoral mechanisms of remote organ crosstalk. Thus, DCD may represent a novel important myokine modulating cardiomyocyte survival and function. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.
    Full-text · Article · Jun 2015 · Cardiovascular Research
  • [Show abstract] [Hide abstract]
    ABSTRACT: A NADP(+) dependent dehydrogenase activity on 3-glutathionyl-4-hydroxynonanal (GSHNE) was purified to electrophoretic homogeneity from a line of human astrocytoma cells (ADF). Proteomic analysis identified this enzymatic activity as associated with carbonyl reductase 1 (E.C. 1.1.1.184). The enzyme is highly efficient at catalyzing the oxidation of GSHNE (KM33µM,kcat.405min(-1)), as it is practically inactive towards trans-4-hydroxy-2-nonenal (HNE) and other HNE-addicted thiol-containing amino acid derivatives. Combined mass spectrometry and nuclear magnetic resonance spectroscopy analysis of the reaction products revealed that carbonyl reductase oxidizes the hydroxyl group of GSHNE in its hemiacetal form, with the formation of the corresponding 3-glutathionyl-nonanoic-δ-lactone. The relevance of this new reaction catalyzed by carbonyl reductase 1 is discussed in terms of HNE detoxification and the recovery of reducing power. Copyright © 2015. Published by Elsevier Inc.
    No preview · Article · Feb 2015 · Free Radical Biology and Medicine
  • Source
    Giovanni Renzone · Simona Arena · Andrea Scaloni
    [Show abstract] [Hide abstract]
    ABSTRACT: The Maillard reaction consists of a number of chemical processes affecting the structure of the proteins present in foods. We previously accomplished the proteomic characterization of the lactosylation targets in commercial milk samples. Although characterizing the early modification derivatives, this analysis did not describe the corresponding advanced glycation end-products (AGEs), which may be formed from the further oxidation of former ones or by reaction of oxidized sugars with proteins, when high temperatures are exploited. To fill this gap, we have used combined proteomic procedures for the systematic characterization of the lactosylated and AGEs-containing proteins from the soluble and milk fat globule membrane fraction of various milk products. Beside to confirm all lactulosyl-lysines described previously, 40 novel lactosylation sites were identified. More importantly, 308 additional intermediate and advanced glycoxidation derivatives (including cross-linking adducts) were characterized in 31 proteins, providing the widest qualitative inventory of modified species ascertained in commercial milk samples so far. Amadori adducts with glucose/galactose, their dehydration products, carboxymethyl-lysine, and glyoxal-, 3-deoxyglucosone/3-deoxygalactosone and 3-deoxylactosone-derived dihydroxyimidazolines and/or hemiaminals were the most frequent derivatives observed. Depending on thermal treatment, a variable number of modification sites was identified within each protein; their number increased with harder food processing conditions. Among the modified proteins, species involved in assisting the delivery of nutrients, defense response against pathogens and cellular proliferation/differentiation were highly affected by AGEs formation. This may lead to a progressive decrease of the milk nutritional value, as it reduces the protein functional properties, abates the bioavailability of the essential amino acids and eventually affects food digestibility. These aspects are of particular importance in products intended for infant diet, such as milk powders and infant formulas. We used combined shotgun proteomic procedures for the systematic characterization of intermediate and advanced glycoxidation protein products in various raw and commercial milk samples. Several hundreds of modified species were characterized as deriving from 31 milk proteins, providing the widest qualitative inventory of assigned components in this fluid. Amadori adducts with glucose/galactose, their dehydration products, carboxymethyl-lysine, and glyoxal-, 3-deoxyglucosone/3-deoxygalactosone and 3-deoxylactosone-derived dihydroxyimidazolines and/or hemiaminals were the most frequent derivatives observed. Proteins involved in nutrient delivery, defense response against pathogens and cellular proliferation/differentiation were highly subjected to intermediate and advanced glycoxidation modification. This may lead to a progressive decrease of the milk nutritional value, as it reduces the protein functional properties, diminishes the bioavailability of the essential amino acids, eventually affects food digestibility and determines a potential increase of specific allergens. These information are important points of interest to connect the extent of the Maillard reaction present in different commercial samples with the potential nutritional aspects mentioned above. These themes have to be fully evaluated in a next future for a complete estimation of the nutritional and toxicological properties of the dairy products deriving from severe heat processing. Copyright © 2015. Published by Elsevier B.V.
    Full-text · Article · Jan 2015 · Journal of Proteomics
  • Source

    Full-text · Dataset · Dec 2014
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Contamination of soil and water by heavy metals has become a widespread problem; environmental pollution by high zinc (Zn) concentration occurs frequently. Although poplar (Populus spp.) has been identified as suitable for phytoremediation approaches, its response to high Zn concentrations are still not clearly understood. For this reason, we investigated the effects of Zn in Populus × euramericana clone I-214 roots by proteomic analysis. Comparative experiments were conducted on rooted woody cuttings grown in nutrient solutions containing 1 mM (treatment) or 1 μM (control) Zn concentrations. A gel-based proteomic approach coupled with morphological and chemical analysis was used to identify differentially represented proteins in treated roots and to investigate the effect of Zn treatment on the poplar root system. Data shows that Zn was accumulated preferentially in roots, that the antioxidant system, the carbohydrate/energy and amino acid metabolisms were the main pathways modulated by Zn excess, and that mitochondria and vacuoles were the cellular organelles predominately affected by Zn stress. A coordination between cell death and proliferation/growth seems to occur under this condition to counteract the Zn-induced damage.
    Full-text · Article · Jul 2014 · Journal of Plant Physiology
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The Maillard reaction includes a complex network of processes affecting food and biopharmaceutical products; it also occurs in living organisms and has been strictly related to cell aging, to the pathogenesis of several (chronic) diseases, such as diabetes, uremia, cataract, liver cirrhosis and various neurodegenerative pathologies, as well as to peritoneal dialysis treatment. Dozens of compounds are involved in this process, among which a number of protein-adducted derivatives that have been simplistically defined as early, intermediate and advanced glycation end-products. In the last decade, various bottom-up proteomic approaches have been successfully used for the identification of glycation/glycoxidation protein targets as well as for the characterization of the corresponding adducts, including assignment of the modified amino acids. This article provides an updated overview of the mass spectrometry-based procedures developed to this purpose, emphasizing their partial limits with respect to current proteomic approaches for the analysis of other post-translational modifications. These limitations are mainly related to the concomitant sheer diversity, chemical complexity, and variable abundance of the various derivatives to be characterized. Some challenges to scientists are finally proposed for future proteomic investigations to solve main drawbacks in this research field. © 2013 Wiley Periodicals, Inc. Mass Spec Rev 9999: 1-29, 2013.
    Full-text · Article · Jan 2014 · Mass Spectrometry Reviews
  • [Show abstract] [Hide abstract]
    ABSTRACT: Woody plants living in temperate climates finely regulate their growth and development in relation to seasonal changes; their transition from vegetative to dormancy phase represents an adaptation to their environment. Events occurring in the shoot during onset/release from dormancy have been largely investigated, whereas in woody roots they remain completely unknown. In recent years, we have been interested in understanding the molecular and physiological events occurring in poplar woody root during release from dormancy. Here, we propose the results of a comparative analysis of the proteome of poplar woody root sampled at different time points: T0 (dormancy condition), T1 (release from dormancy), and T2 (full vegetative condition). This study identified proteins that may be involved in the long-term survival of a dormant root or landmarking a specific time point.
    No preview · Article · Dec 2013 · Plant Biosystems
  • [Show abstract] [Hide abstract]
    ABSTRACT: Milk and dairy products are usually submitted to thermal procedures in order to preserve microbiological safety and to prolong their shelf-life; these actions may eventually induce structural modifications of several components. In particular, milk proteins undergo a non-enzymatic glycation, known as the Maillard reaction, in which reducing sugars (such as lactose) mainly react with the epsilon-amino group of Lys residues, leading to the formation of the Amadori product lactulosyl-lysine. Protein lactosylation leads to a decrease of milk nutritional value as it reduces the bioavailability of the essential amino acid lysine and to a potential increase of the specific allergen activity, due to the formation of new hapten-like antigens. These aspects are of particular importance in products intended for infant diet, such as milk powders and infant milk formulas; accordingly, a detailed structural characterization of the extent and site-specificity of milk protein lactosylation is mandatory. Analytical methodologies based on mass spectrometry and more recently proteomics have been thoroughly applied to the structural analysis of milk proteins and their modified forms, including glycation products. This review highlights the contribution of mass spectrometry to the extensive investigation of lactosylation events in milk proteins, with a particular focus on the most up-to date technological improvements.
    No preview · Article · Nov 2013 · Food Research International
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Aphids are among the most destructive pests in temperate climates, causing significant damage on several crops including tomato. We carried out a transcriptomic and proteomic study to get insights into the molecular mechanisms and dynamics of the tomato response to the Macrosyphum euphorbiae aphid. The time course analysis of aphid infestation indicated a complex, dynamic pattern of gene expression. Several biological functions were affected and genes related to the stress and defence response were the most represented. The Gene Ontology categories of the differentially expressed genes (899) and identified proteins (57) indicated that the tomato response is characterized by an increased oxidative stress accompanied by the production of proteins involved in the detoxification of oxygen radicals. Aphids elicit a defense reaction based on the cross-communication of different hormone-related signaling pathways such as those related to the salicylic acid (SA), jasmonic acid (JA), ethylene and brassinosteroids. Among them, the SA-signaling pathway and stress-responsive SA-dependent genes play a dominant role. Furthermore, tomato response is characterized by a reduced accumulation of photosynthetic proteins and a modification of the expression of various cell wall related genes. Our work allowed a more comprehensive understanding of the signaling events and the defense dynamics of the tomato response to aphids in a compatible interaction and, based on experimental data, a model of the tomato--aphid molecular interaction was proposed. Considering the rapid advancement of tomato genomics, this information will be important for the development of new protection strategies.
    Full-text · Article · Jul 2013 · BMC Genomics
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Temperate perennial woody plants use different environmental signals to coordinate their growth and development in relation to seasonal changes. Preliminary evidences suggest that, even during dormancy, plants maintain effective metabolic activities and molecular mechanisms ensuring them an eventual recording of mechanical loads during winter times. Despite their great importance for productivity and survival, plant biology investigations have poorly characterized the root growth cycle and its response to environmental stresses. In this study, we describe the proteomic changes occurring over the time in poplar root either in the absence or in response to a bending stress; corresponding expression of cell cycle regulator and auxin transporter genes was also evaluated by reverse transcription polymerase chain reaction analysis (RT-PCR). Our results confirm previous evidences on the effect of the bending stress on the anticipation of root growth resumption, providing additional insights on a temporal modulation of various plant metabolic processes involved in dormancy break, growth resumption and stress response in the bent root; these events seem related to the differential compression and tension force distribution occurring over the plant taproot.
    Full-text · Article · May 2013 · Physiologia Plantarum
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Plants, as sessile organisms, are continuously exposed to temperature changes in the environment. Low and high temperature stresses have a great impact on agricultural productivity, since they significantly alter plant metabolism and physiology. Plant response to temperature stress is a quantitative character, being influenced by the degree of stress, time of exposure, as well as plant adaptation ability; it involves profound cellular changes at the proteomic level. We describe here the quantitative variations of the protein repertoire of Arabidopsis thaliana rosette leaves after exposing seedlings to either short-term cold or heat temperature stress. A proteomic approach, based on two-dimensional electrophoresis and MALDI-TOF peptide mass fingerprinting and/or nanoLC-ESI-LIT-MS/MS experiments, was used for this purpose. The comparison of the resulting proteomic maps highlighted proteins showing quantitative variations induced by temperature treatments. Thirty-eight protein spots exhibited significant quantitative changes under at least one stress condition. Identified, differentially-represented proteins belong to two main broad functional groups, namely energy production/carbon metabolism and response to abiotic and oxidative stresses. The role of the identified proteins is discussed here in relation to plant adaptation to cold or heat stresses. Our results suggest a significant overlapping of the responses to opposite temperature extremes.
    Full-text · Article · Apr 2013 · Molecular BioSystems
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Unlabelled: Subclinical mastitis is one of the main causes of alteration in milk content and has a major impact on both animal welfare and economy in the dairy industry. A better knowledge is needed to understand the ovine mammary gland metabolism and its response to bacterial infection. In this study, the proteomic changes in ovine milk as a result of subclinical mastitis were investigated by comparing both whey and fat globule membrane profiles of samples from Staphylococcus chromogenes-positive individuals, with those from non-infected counterparts having high or low somatic cell count; the latter were used as control. 2-DE and combined MS procedures were utilized for this purpose. Although sample bromatological parameters were very similar, proteomic analysis highlighted significant differences between the three experimental groups. Most relevant changes were observed between samples of infected milk and control. Modifications related to the defense response of the mammary gland to the pathogen were evident, with important consequences on nutritional and technological properties of milk. On the other hand, quantitative protein changes between non-infected samples with low and high levels of somatic cells indicated that the latter may result as a consequence of a probable unpaired cellular metabolism due to cellular stress, hormonal variations or previous infections. Putative biomarkers useful for the monitoring of sheep mammary metabolism and for the careful management of ovine subclinical mastitis to avoid its clinical degeneration are proposed and discussed. Biological significance: Proteomics has been here applied to the differentiation of healthy and subclinical mastitic sheep milk samples, evidencing the response of the mammary gland to S. chromogenes infection. Presented results propose useful protein biomarkers for the detection of ewe mammary infection at its subclinical stages and, subsequently, mastitis recognition and treatment. Differently from bovine, these data confirm that the increase in somatic cell count in sheep milk is not always associated with protein factors that characterize the mammary gland infection; accordingly, somatic cell count cannot be considered as a useful parameter to certainly diagnose subclinical mastitis in ovine.
    Full-text · Article · Apr 2013 · Journal of proteomics
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Cladosporols, purified and characterized as secondary metabolites from Cladosporium tenuissimum, display an antifungal activity. In this study, we tested the antiproliferative properties of cladosporol A, the main isoform of this metabolite family, against human cancer cell lines. By assessing cell viability, we found that cladosporol A inhibits the growth of various human colon cancers derived cell lines (HT-29, SW480, and CaCo-2) in a time- and concentration-dependent manner, specifically of HT-29 cells. The reduced cell proliferation was due to a G1-phase arrest, as assessed by fluorescence activated cell sorting analysis on synchronized HT-29 cells, and was associated with an early and robust over-expression of p21(waf1/cip1) , the well-known cyclin-dependent kinases inhibitor. This suggests that the drug may play a role in the control of cancer cell proliferation. Consistently, cyclin D1, cyclin E, CDK2, and CDK4 proteins were reduced and histone H1-associated CDK2 kinase activity inhibited. In addition to p21(waf1/cip1) , exposure to 20 µM cladosporol A caused a simultaneous increase of pERK and pJNK, suggesting that this drug activates a circuit that integrates cell cycle regulation and the signaling pathways both involved in the inhibition of cell proliferation. Finally, we showed that the increase of p21(waf1/cip1) expression was generated by a Sp1-dependent p53-independent stimulation of its gene transcription as mutagenesis of the Sp1 binding sites located in the p21 proximal promoter abolished induction. To our knowledge, this is the first report showing that cladosporol A inhibits colon cancer cell proliferation by modulating p21(waf1/cip1) expression. © 2011 Wiley Periodicals, Inc.
    Full-text · Article · Jan 2013 · Molecular Carcinogenesis
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Carbonic anhydrase IX (CA IX) is a transmembrane protein affecting pH regulation, cell migration/invasion and survival in hypoxic tumors. Although the pathways related to CA IX have begun to emerge, molecular partners mediating its functions remain largely unknown. Here we characterize the CA IX interactome in hypoxic HEK-293 cells. Most of the identified CA IX-binding partners contain the HEAT/ARM repeat domain and belong to the nuclear transport machinery. We show that the interaction with two of these proteins, namely XPO1 exportin and TNPO1 importin, occurs via the C-terminal region of CA IX and increases with protein phosphorylation. We also demonstrate that nuclear CA IX is enriched in hypoxic cells and present in renal cell carcinoma tissues. These data place CA IX among the cell-surface signal transducers undergoing nuclear translocation. Accordingly, CA IX interactome involves also CAND1, which participates in both gene transcription and assembly of SCF ubiquitin ligase complexes. Noteworthy, down-regulation of CAND1 leads to decreased CA IX protein level apparently via affecting its stability. Our findings provide the first evidence that CA IX interacts with proteins involved in nuclear/cytoplasmic transport, gene transcription and protein stability, and suggest the existence of nuclear CA IX protein subpopulations with a potential intracellular function, distinct from the crucial CA IX role at the cell surface.
    Full-text · Article · Nov 2012 · Journal of Proteome Research
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Background A bacterial strain previously isolated from pyrite mine drainage and named BAS-10 was tentatively identified as Klebsiella oxytoca. Unlikely other enterobacteria, BAS-10 is able to grow on Fe(III)-citrate as sole carbon and energy source, yielding acetic acid and CO2 coupled with Fe(III) reduction to Fe(II) and showing unusual physiological characteristics. In fact, under this growth condition, BAS-10 produces an exopolysaccharide (EPS) having a high rhamnose content and metal-binding properties, whose biotechnological applications were proven as very relevant. Results Further phylogenetic analysis, based on 16S rDNA sequence, definitively confirmed that BAS-10 belongs to K. oxytoca species. In order to rationalize the biochemical peculiarities of this unusual enterobacteriun, combined 2D-Differential Gel Electrophoresis (2D-DIGE) analysis and mass spectrometry procedures were used to investigate its proteomic changes: i) under aerobic or anaerobic cultivation with Fe(III)-citrate as sole carbon source; ii) under anaerobic cultivations using Na(I)-citrate or Fe(III)-citrate as sole carbon source. Combining data from these differential studies peculiar levels of outer membrane proteins, key regulatory factors of carbon and nitrogen metabolism and enzymes involved in TCA cycle and sugar biosynthesis or required for citrate fermentation and stress response during anaerobic growth on Fe(III)-citrate were revealed. The protein differential regulation seems to ensure efficient cell growth coupled with EPS production by adapting metabolic and biochemical processes in order to face iron toxicity and to optimize energy production. Conclusion Differential proteomics provided insights on the molecular mechanisms necessary for anaeorobic utilization of Fe(III)-citrate in a biotechnologically promising enterobacteriun, also revealing genes that can be targeted for the rational design of high-yielding EPS producer strains.
    Full-text · Article · Nov 2012 · Microbial Cell Factories
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The fruit fly Bactrocera oleae is the primary biotic stressor of cultivated olives, causing direct and indirect damages that significantly reduce both the yield and the quality of olive oil. To study the olive-B. oleae interaction, we conducted transcriptomic and proteomic investigations of the molecular response of the drupe. The identifications of genes and proteins involved in the fruit response were performed using a Suppression Subtractive Hybridisation technique and a combined bi-dimensional electrophoresis/nanoLC-ESI-LIT-MS/MS approach, respectively. We identified 196 ESTs and 26 protein spots as differentially expressed in olives with larval feeding tunnels. A bioinformatic analysis of the identified non-redundant EST and protein collection indicated that different molecular processes were affected, such as stress response, phytohormone signalling, transcriptional control and primary metabolism, and that a considerable proportion of the ESTs could not be classified. The altered expression of 20 transcripts was also analysed by real-time PCR, and the most striking differences were further confirmed in the fruit of a different olive variety. We also cloned the full-length coding sequences of two genes, Oe-chitinase I and Oe-PR27, and showed that these are wound-inducible genes and activated by B. oleae punctures. This study represents the first report that reveals the molecular players and signalling pathways involved in the interaction between the olive fruit and its most damaging biotic stressor. Drupe response is complex, involving genes and proteins involved in photosynthesis as well as in the production of ROS, the activation of different stress response pathways and the production of compounds involved in direct defence against phytophagous larvae. Among the latter, trypsin inhibitors should play a major role in drupe resistance reaction.
    Full-text · Article · Jun 2012 · BMC Plant Biology

Publication Stats

876 Citations
200.92 Total Impact Points

Institutions

  • 2015
    • Duke University Medical Center
      • Department of Medicine
      Durham, North Carolina, United States
  • 2008-2015
    • INO - Istituto Nazionale di Ottica
      Florens, Tuscany, Italy
  • 2005-2013
    • National Research Council
      • • Laboratory of Rare Gas Mass Spectrometry
      • • Institute of Plant Genetics IGV
      Roma, Latium, Italy
  • 2012
    • Università degli Studi di Perugia
      Perugia, Umbria, Italy
  • 2009
    • University of Udine
      • Department of Medical and Biological Sciences
      Udine, Friuli Venezia Giulia, Italy
  • 2006
    • Polo d'Innovazione di Genomica Genetica e Biologia
      Perugia, Umbria, Italy