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991.
Francesca Chignola Massimiliano Gaetani Ana Rebane Tnis Org Luca Mollica Chiara Zucchelli Andrea Spitaleri Valeria Mannella Prt Peterson Giovanna Musco 《Nucleic acids research》2009,37(9):2951-2961
Plant homeodomain (PHD) fingers are often present in chromatin-binding proteins and have been shown to bind histone H3 N-terminal tails. Mutations in the autoimmune regulator (AIRE) protein, which harbours two PHD fingers, cause a rare monogenic disease, autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED). AIRE activates the expression of tissue-specific antigens by directly binding through its first PHD finger (AIRE-PHD1) to histone H3 tails non-methylated at K4 (H3K4me0). Here, we present the solution structure of AIRE-PHD1 in complex with H3K4me0 peptide and show that AIRE-PHD1 is a highly specialized non-modified histone H3 tail reader, as post-translational modifications of the first 10 histone H3 residues reduce binding affinity. In particular, H3R2 dimethylation abrogates AIRE-PHD1 binding in vitro and reduces the in vivo activation of AIRE target genes in HEK293 cells. The observed antagonism by R2 methylation on AIRE-PHD1 binding is unique among the H3K4me0 histone readers and represents the first case of epigenetic negative cross-talk between non-methylated H3K4 and methylated H3R2. Collectively, our results point to a very specific histone code responsible for non-modified H3 tail recognition by AIRE-PHD1 and describe at atomic level one crucial step in the molecular mechanism responsible for antigen expression in the thymus. 相似文献
992.
TIMP-1-GPI in combination with hyperthermic treatment of melanoma increases sensitivity to FAS-mediated apoptosis 总被引:1,自引:0,他引:1
Djafarzadeh R Milani V Rieth N von Luettichau I Skrablin PS Hofstetter M Noessner E Nelson PJ 《Cancer immunology, immunotherapy : CII》2009,58(3):361-371
Resistance to apoptosis is a prominent feature of malignant melanoma. Hyperthermic therapy can be an effective adjuvant treatment
for some tumors including melanoma. We developed a fusion protein based on the tissue inhibitor of matrix metalloproteinase-1
linked to a glycosylphosphatidylinositol anchor (TIMP-1-GPI). The TIMP-1-GPI-fusion protein shows unique properties. Exogenous
administration of TIMP-1-GPI can result in transient morphological changes to treated cells including modulation of proliferation
and decreased resistance to apoptosis. The effect of TIMP-1-GPI on the biology of melanoma in the context of a defined hyperthermic
dose was evaluated in vitro. Clonogenic assays were used to measure cell survival. Gelatinase zymography determined secretion
of MMP-2 and MMP-9. Monoclonal antibody against FAS/CD95 was applied to induce apoptosis. The expression of pro- and anti-apoptotic
proteins and the secretion of immunoregulatory cytokines were then evaluated using Western blot and ELISA. TIMP-1-GPI combined
with a sub-lethal hyperthermic treatment (41.8°C for 2 h) suppressed tumor cell growth capacity as measured by clonogenic
assay. The co-treatment also significantly suppressed tumor cell proliferation, enhanced FAS receptor surface expression increased
tumor cell susceptibility to FAS-mediated killing. The increased sensitivity to FAS-induced apoptosis was linked to alterations
in the apoptotic mediators Bcl-2, Bax, Bcl-XL and Apaf-1. The agent works in concert with sub-lethal hyperthermic treatment
to render melanoma cells sensitive to FAS killing. The targeted delivery of TIMP-1-GPI to tumor environments in the context
of regional hyperthermic therapy could be optimized through the use of thermosensitive liposomes.
Elfriede Noessner, Peter J. Nelson are equal contributors. 相似文献
993.
In angiosperms, auxin phytohormones play a crucial regulatory role in fruit initiation. The expression of auxin biosynthesis genes in ovules and placenta results in uncoupling of tomato (Solanum lycopersicum) fruit development from fertilization with production of parthenocarpic fruits. We have identified two newly described genes, named Aucsia genes, which are differentially expressed in auxin-synthesis (DefH9-iaaM) parthenocarpic tomato flower buds. The two tomato Aucsia genes encode 53-amino-acid-long peptides. We show, by RNA interference-mediated gene suppression, that Aucsia genes are involved in both reproductive and vegetative plant development. Aucsia-silenced tomato plants exhibited auxin-related phenotypes such as parthenocarpic fruit development, leaf fusions, and reflexed leaves. Auxin-induced rhizogenesis in cotyledon explants and polar auxin transport in roots were reduced in Aucsia-silenced plants compared with wild-type plants. In addition, Aucsia-silenced plants showed an increased sensitivity to 1-naphthylphthalamic acid, an inhibitor of polar auxin transport. We further prove that total indole-3-acetic acid content was increased in preanthesis Aucsia-silenced flower buds. Thus, the data presented demonstrate that Aucsia genes encode a novel family of plant peptides that control fruit initiation and affect other auxin-related biological processes in tomato. Aucsia homologous genes are present in both chlorophytes and streptophytes, and the encoded peptides are distinguished by a 16-amino-acid-long (PYSGXSTLALVARXSA) AUCSIA motif, a lysine-rich carboxyl-terminal region, and a conserved tyrosine-based endocytic sorting motif. 相似文献
994.
Valeria Boeris Darío Spelzini Beatriz Farruggia Guillermo Picó 《Process Biochemistry》2009,44(11):1260-1264
The combination of two bioseparation techniques, partition in aqueous two-phase systems and polyelectrolyte precipitation of the target enzyme from the phase where it is present, was assayed to purify pepsin from bovine abomasum homogenate. Pepsin was partitioned in favor of the polyethyleneglycol-rich phase in an aqueous two-phase system of polyethyleneglycol 600 and 1450-sodium phosphate; however, a great amount of impure proteins were present. Chitosan (a cationic natural polyelectrolyte) was added to precipitate this acid enzyme as a form of insoluble complex. The addition of this second step increased the purity of the enzyme significantly while the yield was not significantly decreased. The combination of both partition in polyethyleneglycol 1450-phosphate system and chitosan precipitation produced a pepsin recovery of 48.5% with a purification factor of 9.0. The biological activity of the recovered enzyme remained unaltered. 相似文献
995.
Bacterial and archaeal populations at two shallow hydrothermal vents off Panarea Island (Eolian Islands, Italy) 总被引:1,自引:0,他引:1
Teresa Luciana Maugeri Valeria Lentini Concetta Gugliandolo Francesco Italiano Sylvie Cousin Erko Stackebrandt 《Extremophiles : life under extreme conditions》2009,13(1):199-212
The aim of this study was to investigate the microbial community thriving at two shallow hydrothermal vents off Panarea Island
(Italy). Physico-chemical characteristics of thermal waters were examined in order to establish the effect of the vents on
biodiversity of both Bacteria and Archaea. Water and adjacent sediment samples were collected at different times from two
vents, characterised by different depth and temperature, and analysed to evaluate total microbial abundances, sulphur-oxidising
and thermophilic aerobic bacteria. Total microbial abundances were on average of the order of 105 cells ml−1, expressed as picoplanktonic size fraction. Picophytoplanktonic cells accounted for 0.77–3.83% of the total picoplanktonic
cells. The contribution of bacterial and archaeal taxa to prokaryotic community diversity was investigated by PCR–DGGE fingerprinting
method. The number of bands derived from bacterial DNA was highest in the DGGE profiles of water sample from the warmest and
deepest site (site 2). In contrast, archaeal richness was highest in the water of the coldest and shallowest site (site 1).
Sulphur-oxidising bacteria were detected by both culture-dependent and -independent methods. The primary production at the
shallow hydrothermal system of Panarea is supported by a complex microbial community composed by phototrophs and chemolithotrophs. 相似文献
996.
Breitbart M Hoare A Nitti A Siefert J Haynes M Dinsdale E Edwards R Souza V Rohwer F Hollander D 《Environmental microbiology》2009,11(1):16-34
Ancient biologically mediated sedimentary carbonate deposits, including stromatolites and other microbialites, provide insight into environmental conditions on early Earth. The primary limitation to interpreting these records is our lack of understanding regarding microbial processes and the preservation of geochemical signatures in contemporary microbialite systems. Using a combination of metagenomic sequencing and isotopic analyses, this study describes the identity, metabolic potential and chemical processes of microbial communities from living microbialites from Cuatro Ciénegas, Mexico. Metagenomic sequencing revealed a diverse, redox-dependent microbial community associated with the microbialites. The microbialite community is distinct from other marine and freshwater microbial communities, and demonstrates extensive environmental adaptation. The microbialite metagenomes contain a large number of genes involved in the production of exopolymeric substances and the formation of biofilms, creating a complex, spatially structured environment. In addition to the spatial complexity of the biofilm, microbial activity is tightly controlled by sensory and regulatory systems, which allow for coordination of autotrophic and heterotrophic processes. Isotopic measurements of the intracrystalline organic matter demonstrate the importance of heterotrophic respiration of photoautotrophic biomass in the precipitation of calcium carbonate. The genomic and stable isotopic data presented here significantly enhance our evolving knowledge of contemporary biomineralization processes, and are directly applicable to studies of ancient microbialites. 相似文献
997.
Fiammetta Berlinguer Manuela Madeddu Valeria Pasciu Sara Succu Antonio Spezzigu Valentina Satta Paolo Mereu Giovanni G Leoni Salvatore Naitana 《Reproductive biology and endocrinology : RB&E》2009,7(1):125
Currently, the assessment of sperm function in a raw or processed semen sample is not able to reliably predict sperm ability
to withstand freezing and thawing procedures and in vivo fertility and/or assisted reproductive biotechnologies (ART) outcome.
The aim of the present study was to investigate which parameters among a battery of analyses could predict subsequent spermatozoa
in vitro fertilization ability and hence blastocyst output in a goat model. Ejaculates were obtained by artificial vagina
from 3 adult goats (Capra hircus) aged 2 years (A, B and C). In order to assess the predictive value of viability, computer
assisted sperm analyzer (CASA) motility parameters and ATP intracellular concentration before and after thawing and of DNA
integrity after thawing on subsequent embryo output after an in vitro fertility test, a logistic regression analysis was used.
Individual differences in semen parameters were evident for semen viability after thawing and DNA integrity. Results of IVF
test showed that spermatozoa collected from A and B lead to higher cleavage rates (0 < 0.01) and blastocysts output (p < 0.05)
compared with C. Logistic regression analysis model explained a deviance of 72% (p < 0.0001), directly related with the mean
percentage of rapid spermatozoa in fresh semen (p < 0.01), semen viability after thawing (p < 0.01), and with two of the three
comet parameters considered, i.e tail DNA percentage and comet length (p < 0.0001). DNA integrity alone had a high predictive
value on IVF outcome with frozen/thawed semen (deviance explained: 57%). The model proposed here represents one of the many
possible ways to explain differences found in embryo output following IVF with different semen donors and may represent a
useful tool to select the most suitable donors for semen cryopreservation. 相似文献
998.
Valeria Valente Silvia A Teixeira Luciano Neder Oswaldo K Okamoto Sueli M Oba-Shinjo Suely KN Marie Carlos A Scrideli Maria L Pa?ó-Larson Carlos G Carlotti 《BMC molecular biology》2009,10(1):17
Background
Considering the broad variation in the expression of housekeeping genes among tissues and experimental situations, studies using quantitative RT-PCR require strict definition of adequate endogenous controls. For glioblastoma, the most common type of tumor in the central nervous system, there was no previous report regarding this issue. 相似文献999.
Valeria Tigini Valeria Prigione Sara Di Toro Fabio Fava Giovanna C Varese 《Microbial cell factories》2009,8(1):5-14
Background
Polychlorinated biphenyls (PCBs) are widespread toxic pollutants. Bioremediation might be an effective, cost competitive and environment-friendly solution for remediating environmental matrices contaminated by PCBs but it is still unsatisfactory, mostly for the limited biodegradation potential of bacteria involved in the processes. Very little is known about mitosporic fungi potential in PCB bioremediation and their occurrence in actual site historically contaminated soils. In the present study, we characterised the native mycoflora of an aged dump site soil contaminated by about 0.9 g kg-1 of Aroclor 1260 PCBs and its changing after aerobic biotreatment with a commercial complex source of bacteria and fungi. Fungi isolated from the soil resulting from 120 days of treatment were screened for their ability to adsorb or metabolise 3 target PCBs. 相似文献1000.
Alessandro Terrinoni Andrea Codispoti Valeria Serra Biagio Didona Steven Nisticò Bianca Napolitano Gerry Melino 《Biochemical and biophysical research communications》2010,395(1):25-30
KID syndrome (MIM 148210) is an ectodermal dysplasia characterized by the occurrence of localized erythematous scaly skin lesions, keratitis and severe bilateral sensorineural deafness. KID syndrome is inherited as an autosomic dominant disease, due to mutations in the gene encoding gap junction protein GJB2 (connexin 26, Cx26). Cx26 is a component of gap junction channels in the epidermis and in the stria vascularis of the cochlea. These channels play a role in the coordinated exchange of molecules and ions occurring in a wide spectrum of cellular activities. In this paper we describe two patients with Cx26 mutations cause cell death by the alteration of protein trafficking, membrane localization and probably interfering with intracellular ion concentrations. We discuss the pathogenesis of both the hearing and skin phenotypes. 相似文献