927 resultados para motif
Resumo:
Embobied Object, Material Family. Late-Medieval Wood Sculptures Depicting Saint Anne with the Virgin and Child in Finland Saint Anne, the mother of the Virgin Mary, was one of the most popular saints in Western Europe in the late Middle Ages. She was often depicted with two other figures, the Virgin and the Christ Child (Anna Selbdritt). The dissertation examines the polychrome wood sculptures showing this motif, with a special focus on those remaining in Finland. It investigates the meanings these sculptures had to their observers in the fifteenth-century Finland. The study sheds light to important material heritage which is little known and offers new insights into the cult and imagery of the holy grandmother. Methodologically the study is based on iconology and post-formalist art history, and it appropriates concepts such as spatiality, sanctity, corporeality, and gender. Taking a comparative approach it knits together larger tendencies and local people and incidents. By conflating methodological domains it renews the ways how fragmentary wood sculptures, lacking documentary written sources, can be contextually interpreted and comprehended. The sculptures are analyzed from three angles. Firstly, the study explores the sculptures by focusing on their materiality and facture, which is to consider them as records of their own making. The analysis provides new information concerning the quantity, location, and current condition of the sculptures and it also elucidates problems regarding attribution, dating, display, and craftsmanship. The book presents the results of the empirical study of 45 Saint Anne groups; these works are individually described in the large Appendix. Secondly, the works are contextualized to the specific historical conditions in which they were observed. The study discusses closely the circumstances in the Turku Cathedral around the shrine of Saint Anne, the popular belief, and the piety of individual persons. The sculptures, deemed as the embodiments of the holy characters, interacted with the devotees. Thirdly, the works are examined within the wider theological and ideological currents of the era centered on the body and Incarnation. Saint Anne with the Virgin and Child motif demonstrated the Carnal Trinity, the motherly side of the Holy Trinity. The dissertation argues that Saint Anne was interpreted as the female counterpart or, in a mythical sense, wife of God. Furthermore, the Child s implicit, simultaneous presence as a suffering or dead man imbues the sculptures with a sense of the Passion, thus associating them with the pietà and the Mater dolorosa motifs. The naked Christ Child underlines him as the offering and, eventually, the Eucharistic wafer. The study suggests that the sculptures mediate continuity and the bloodline between the generations by the intertwined and repeated gestures, clothing and positions of the portrayed figures. Regardless of the ostensible homeliness of the sculptures, so readily reiterated by earlier scholars, these sculptures represented creation and birth through the carnal yet holy mothers.
Resumo:
Examination of the symmetric Hantzsch 1,4-dihydropyridine ester derivatives of the prototypical nifedipine molecule indicates the tendency of this class of molecule to form a common packing motif. Crystal structure analysis of 2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylic diesters and analogs reveals that they form extended chains, characterized as the C(6) packing motif, via intermolecular (amine) N-H...O=C (C3,C5 carbonyl) hydrogen bonds. In addition, all the prepared derivatives also satisfy the basic structural requirements for their high binding efficiency to the receptor. The reproducible C(6) packing motif observed among these compounds has a use in the design of solid-state materials.
Resumo:
Abacá mosaic virus (AbaMV) is related to members of the sugarcane mosaic virus subgroup of the genus Potyvirus. The ~2 kb 3′ terminal region of the viral genome was sequenced and, in all areas analysed, found to be most similar to Sugarcane mosaic virus (SCMV) and distinct from Johnsongrass mosaic virus (JGMV), Maize dwarf mosaic virus (MDMV) and Sorghum mosaic virus (SrMV). Cladograms of the 3′ terminal region of the NIb protein, the coat protein core and the 3′ untranslated region showed that AbaMV clustered with SCMV, which was a distinct clade and separate from JGMV, MDMV and SrMV. The N-terminal region of the AbaMV coat protein had a unique amino acid repeat motif different from those previously published for other strains of SCMV. The first experimental transmission of AbaMV from abacá (Musa textilis) to banana (Musa sp.), using the aphid vectors Rhopalosiphum maidis and Aphis gossypii, is reported. Polyclonal antisera for the detection of AbaMV in western blot assays and ELISA were prepared from recombinant coat protein expressed in E. coli. A reverse transcriptase PCR diagnostic assay, with microtitre plate colourimetric detection, was developed to discriminate between AbaMV and Banana bract mosaic virus, another Musa-infecting potyvirus. Sequence data, host reactions and serological relationships indicate that AbaMV should be considered a distinct strain of SCMV, and the strain designation SCMV-Ab is suggested.
Resumo:
We completed the genome sequence of Lettuce necrotic yellows virus (LNYV) by determining the nucleotide sequences of the 4a (putative phosphoprotein), 4b, M (matrix protein), G (glycoprotein) and L (polymerase) genes. The genome consists of 12,807 nucleotides and encodes six genes in the order 3′ leader-N-4a(P)-4b-M-G-L-5′ trailer. Sequences were derived from clones of a cDNA library from LNYV genomic RNA and from fragments amplified using reverse transcription-polymerase chain reaction. The 4a protein has a low isoelectric point characteristic for rhabdovirus phosphoproteins. The 4b protein has significant sequence similarities with the movement proteins of capillo- and trichoviruses and may be involved in cell-to-cell movement. The putative G protein sequence contains a predicted 25 amino acids signal peptide and endopeptidase cleavage site, three predicted glycosylation sites and a putative transmembrane domain. The deduced L protein sequence shows similarities with the L proteins of other plant rhabdoviruses and contains polymerase module motifs characteristic for RNA-dependent RNA polymerases of negative-strand RNA viruses. Phylogenetic analysis of this motif among rhabdoviruses placed LNYV in a group with other sequenced cytorhabdoviruses, most closely related to Strawberry crinkle virus.
Resumo:
We demonstrate the aptitude of supramolecular hydrogel formation using simple bile acid such as lithocholic acid in aqueous solution in the presence of various dimeric or oligomeric amines. By variation of the choice of the amines in such mixtures the gelation properties could be modulated. However, the replacement of lithocholic acid (LCA) by cholic acid or deoxycholic acid resulted in no hydrogel formation. FT-IR studies confirm that the carboxylate and ammonium residues of the two components are involved in the salt (ion-pair) formation. This promotes further assembly of the components reinforced by a continuous hydrogen bonded network leading to gelation. Electron microscopy shows the morphology of the internal organization of gels of two component systems which also depends significantly on the amine part. Variation of the amine component from the simple 1,2-ethanediamine (EDA) to oligomeric amines in such gels of lithocholic acid changes the morphology of the assembly from long one-dimensional nanotubes to three-dimensional complex structures. Single crystal X-ray diffraction analysis with one of the amine-LCA complexes suggested the motif of fiber formation where the amines interact with the carboxylate and hydroxyl moieties through electrostatic forces and hydrogen bonding. From small angle neutron scattering study, it becomes clear that the weak gel from LCA-EDA shows scattering oscillation due to the presence of non-interacting nanotubules while for gels of LCA with oligomeric amines the individual fibers come together to form complex three-dimensional organizations of higher length scale. The rheological properties of this class of two component system provide clear evidence that the flow behavior can be modulated varying the acid-amine ratio.
Resumo:
Avibacterium paragallinarum is the causative agent of infectious coryza. The protective antigens of this important pathogen have not yet been clearly identified. In this paper, we applied phage display technique to screen the immunodominant mimotopes of a serovar A strain of A. paragallinarum by using a random 12-peptide library, and evaluated the immunogenicity in chickens of the selected mimotope. Polyclonal antibody directed against A. paragallinarum strain 0083 (serovar A) was used as the target antibody and phage clones binding to this target were screened from the 12-mer random peptide library. More than 50% of the phage clones selected in the third round carried the consensus peptide motif sequence A-DP(M)L. The phage clones containing the peptide motif reacted with the target antibody and this interaction could be blocked, in a dose-dependent manner, by A. paragallinarum. One of the peptide sequences, YGLLAVDPLFKP, was selected and the corresponding oligonucleotide sequence was synthesized and then inserted into the expression vector pFliTrx. The recombinant plasmid was transferred into an expression host Escherichia coli GI826 by electroporation, resulting in a recombinant E. coli expressing the peptide on the bacterial surface. Intramuscular injection of the epitope-expressing recombinant bacteria into chickens induced a specific serological response to serovar A. A. paragallinarum. The chickens given the recombinant E. coli showed significant protection against challenge with A. paragallinarum 0083. These results indicated a potential for the use of the mimotope in the development of molecular vaccines for infectious coryza.
Resumo:
Gemini viral assembly and transport of viral DNA into nucleus for replication, ssentially involve DNA-coat protein interactions. The kinetics of interaction of Cotton LeafCtirl Kokhran Virus-Dabawali recombinant coat protein (rCP) with DNA was studied by electrophoretic mobility shift assay (EMSA) and Surface plasmon resonance (SPR). The rCP interacted with ssDNA with a K-A, of 2.6 +/- 0.29 x 10(8) M-1 in a sequence non-specific manner. The CP has a conserved C2H2 type zinc finger motif composed of residues C68, C72, H81 and H85. Mutation of these residues to alanine resulted in reduced binding to DNA probes. The H85A mutant rCP showed the least binding with approximately 756 fold loss in the association rate and a three order magnitude decrease in the binding affinity as compared to rCP. The CP-DNA interactions via the zinc finger motif could play a Crucial role ill Virus assembly and in nuclear transport. (C) 2009 Elsevier Inc.
Resumo:
Mitochondria have evolved from endosymbiotic alpha-proteobacteria. During the endosymbiotic process early eukaryotes dumped the major component of the bacterial cell wall, the peptidoglycan layer. Peptidoglycan is synthesized and maintained by active-site serine enzymes belonging to the penicillin-binding protein and the β-lactamase superfamily. Mammals harbor a protein named LACTB that shares sequence similarity with bacterial penicillin-binding proteins and β-lactamases. Since eukaryotes lack the synthesis machinery for peptidoglycan, the physiological role of LACTB is intriguing. Recently, LACTB has been validated in vivo to be causative for obesity, suggesting that LACTB is implicated in metabolic processes. The aim of this study was to investigate the phylogeny, structure, biochemistry and cell biology of LACTB in order to elucidate its physiological function. Phylogenetic analysis revealed that LACTB has evolved from penicillin binding-proteins present in the bacterial periplasmic space. A structural model of LACTB indicates that LACTB shares characteristic features common to all penicillin-binding proteins and β-lactamases. Recombinat LACTB protein expressed in E. coli was recovered in significant quantities. Biochemical and cell biology studies showed that LACTB is a soluble protein localized in the mitochondrial intermembrane space. Further analysis showed that LACTB preprotein underwent proteolytic processing disclosing an N-terminal tetrapeptide motif also found in a set of cell death-inducing proteins. Electron microscopy structural studies revealed that LACTB can polymerize to form stable filaments with lengths ranging from twenty to several hundred nanometers. These data suggest that LACTB filaments define a distinct microdomain in the intermembrane space. A possible role of LACTB filaments is proposed in the intramitochondrial membrane organization and microcompartmentation. The implications of these findings offer novel insight into the evolution of mitochondria. Further studies of the LACTB function might provide a tool to treat mitochondria-related metabolic diseases.
Resumo:
Genome-wide association studies followed by replication provide a powerful approach to map genetic risk factors for asthma. We sought to search for new variants associated with asthma and attempt to replicate the association with four loci reported previously (ORMDL3, PDE4D, DENND1B and IL1RL1). Genome-wide association analyses of individual single nucleotide polymorphisms (SNPs), rare copy number variants (CNVs) and overall CNV burden were carried out in 986 asthma cases and 1846 asthma-free controls from Australia. The most-associated locus in the SNP analysis was ORMDL3 (rs6503525, P = 4.8 x 10(-)(7)). Five other loci were associated with P < 10(-)(5), most notably the chemokine CXC motif ligand 14 (CXCL14) gene (rs31263, P = 7.8 x 10(-)(6)). We found no evidence for association with the specific risk variants reported recently for PDE4D, DENND1B and ILR1L1. However, a variant in IL1RL1 that is in low linkage disequilibrium with that reported previously was associated with asthma risk after accounting for all variants tested (rs10197862, gene wide P = 0.01). This association replicated convincingly in an independent cohort (P = 2.4 x 10(-)(4)). A 300-kb deletion on chromosome 17q21 was associated with asthma risk, but this did not reach experiment-wide significance. Asthma cases and controls had comparable CNV rates, length and number of genes affected by deletions or duplications. In conclusion, we confirm the association between asthma risk and variants in ORMDL3 and identify a novel risk variant in IL1RL1. Follow-up of the 17q21 deletion in larger cohorts is warranted.
Resumo:
Colorectal cancer (CRC) is one of the most frequent malignancies in Western countries. Inherited factors have been suggested to be involved in 35% of CRCs. The hereditary CRC syndromes explain only ~6% of all CRCs, indicating that a large proportion of the inherited susceptibility is still unexplained. Much of the remaining genetic predisposition for CRC is probably due to undiscovered low-penetrance variations. This study was conducted to identify germline and somatic changes that contribute to CRC predisposition and tumorigenesis. MLH1 and MSH2, that underlie Hereditary non-polyposis colorectal cancer (HNPCC) are considered to be tumor suppressor genes; the first hit is inherited in the germline and somatic inactivation of the wild type allele is required for tumor initiation. In a recent study, frequent loss of the mutant allele in HNPCC tumors was detected and a new model, arguing against the two-hit hypothesis, was proposed for somatic HNPCC tumorigenesis. We tested this hypothesis by conducting LOH analysis on 25 colorectal HNPCC tumors with a known germline mutation in the MLH1 or MSH2 genes. LOH was detected in 56% of the tumors. All the losses targeted the wild type allele supporting the classical two-hit model for HNPCC tumorigenesis. The variants 3020insC, R702W and G908R in NOD2 predispose to Crohn s disease. Contribution of NOD2 to CRC predisposition has been examined in several case-control series, with conflicting results. We have previously shown that 3020insC does not predispose to CRC in Finnish CRC patients. To expand our previous study the variants R702W and G908R were genotyped in a population-based series of 1042 Finnish CRC patients and 508 healthy controls. Association analyses did not show significant evidence for association of the variants with CRC. Single nucleotide polymorphism (SNP) rs6983267 at chromosome 8q24 was the first CRC susceptibility variant identified through genome-wide association studies. To characterize the role of rs6983267 in CRC predisposition in the Finnish population, we genotyped the SNP in the case-control material of 1042 cases and 1012 controls and showed that G allele of rs6983267 is associated with the increased risk of CRC (OR 1.22; P=0.0018). Examination of allelic imbalance in the tumors heterozygous for rs6983267 revealed that copy number increase affected 22% of the tumors and interestingly, it favored the G allele. By utilizing a computer algorithm, Enhancer Element Locator (EEL), an evolutionary conserved regulatory motif containing rs6983267 was identified. The SNP affected the binding site of TCF4, a transcription factor that mediates Wnt signaling in cells, and has proven to be crucial in colorectal neoplasia. The preferential binding of TCF4 to the risk allele G was showed in vitro and in vivo. The element drove lacZ marker gene expression in mouse embryos in a pattern that is consistent with genes regulated by the Wnt signaling pathway. These results suggest that rs6983267 at 8q24 exerts its effect in CRC predisposition by regulating gene expression. The most obvious target gene for the enhancer element is MYC, residing ~335 kb downstream, however further studies are required to establish the transcriptional target(s) of the predicted enhancer element.
Resumo:
Gene therapy is a promising novel approach for treating cancers resistant to or escaping currently available modalities. Treatment approaches are based on taking advantage of molecular differences between normal and tumor cells. Various strategies are currently in clinical development with adenoviruses as the most popular vehicle. Recent developments include improving targeting strategies for gene delivery to tumor cells with tumor specific promoters or infectivity enhancement. A rapidly developing field is as well replication competent agents, which allow improved tumor penetration and local amplification of the anti-tumor effect. Adenoviral cancer gene therapy approaches lack cross-resistance with other treatment options and therefore synergistic effects are possible. This study focused on development of adenoviral vectors suitable for treatment of various gynecologic cancer types, describing the development of the field from non-replicating adenoviral vectors to multiple-modified conditional replicating viruses. Transcriptional targeting of gynecologic cancer cells by the use of the promoter of vascular endothelial growth factor receptor type 1 (flt-1) was evaluated. Flt-1 is not expressed in the liver and thus an ideal promoter for transcriptional targeting of adenoviruses. Our studies implied that the flt-1 promoter is active in teratocarcinomas.and therefore a good candidate for development of oncolytic adenoviruses for treatment of this often problematic disease with then poor outcome. A tropism modified conditionally replicating adenovirus (CRAd), Ad5-Δ24RGD, was studied in gynecologic cancers. Ad5-Δ24RGD is an adenovirus selectively replication competent in cells defective in the p16/Rb pathway, including many or most tumor cells. The fiber of Ad5-Δ24RGD contains an integrin binding arginine-glycine-aspartic acid motif (RGD-4C), allowing coxackie-adenovirus receptor independent infection of cancer cells. This approach is attractive because expression levels of CAR are highly variable and often low on primary gynecological cancer cells. Oncolysis could be shown for a wide variety of ovarian and cervical cancer cell lines as well as primary ovarian cancer cell spheroids, a novel system developed for in vitro analysis of CRAds on primary tumor substrates. Biodistribution was evaluated and preclinical safety data was obtained by demonstrating lack of replication in human peripheral blood mononuclear cells. The efficicacy of Ad5-Δ24RGD was shown in different orthotopic murine models including a highly aggressive intraperitoneal model of disseminated ovarian cancer cells, where Ad5-Δ24RGD resulted in complete eradication of intraperitoneal disease in half of the mice. To further improve the selectivity and specificity of CRAds, triple-targeted oncolytic adenoviruses were cloned, featuring the cyclo-oxygenase-2 (cox-2) promoter, E1A transcomplementation and serotype chimerism. Those viruses were evaluated on ovarian cancer cells for specificity and oncolytic potency with regard to two different cox2 versions and three different variants of E1A (wild type, delta24 and delta2delta24). Ad5/3cox2Ld24 emerged as the best combination due to enhanced selectivity without potency lost in vitro or in an aggressive intraperitoneal orthotopic ovarian tumor model. In summary, the preclinical therapeutic efficacy of the CRAds tested in this study, taken together with promising biodistribution and safety data, suggest that these CRAds are interesting candidates for translation into clinical trials for gynecologic cancer.
Resumo:
Mulibrey nanism is a hereditary developmental disorder, characterized by prenatal onset growth failure without postnatal catch-up growth, distinctive craniofacial features, progressive cardiopathy and failure of sexual maturation. In addition, the patients develop insulin resistance syndrome and type 2 diabetes and they have an increased risk of developing tumors. The TRIM37 gene that underlies mulibrey nanism encodes for a member of the tripartite motif (TRIM) protein family. The physiological function of TRIM37 and the pathogenetic mechanisms leading from TRIM37 dysfunction to the mulibrey nanism phenotype are unknown. However, TRIM37 localizes at least partially to peroxisomes, and possesses ubiquitin E3-ligase activity. Thus, it may mediate ubiquitin dependent protein degradation, suggesting that accumulation of yet unknown substrate proteins may underlie the disease pathogenesis. In this study, the TRIM37 gene was characterized in detail. A transcription initiation window, with several separate transcription start sites, was identified and the putative promoter region immediately upstream from the transcription initiation window was shown to possess basal promoter activity. Further, several alternative splice variants of the gene were identified, including a highly expressed testis specific variant, encoding for an identical protein product with the main transcript. Expression of TRIM37 mRNA was detected in several different tissues, with highest expression seen in testis and in brain, when the expression patterns of the two major transcripts in different human tissues were studied by quantitative real-time PCR. Several mulibrey nanism patients were studied and thirteen novel mutations in TRIM37 were found, including three mutations (p.Gly322Val, p.Cys109Ser, p.Glu271_Ser287), that are likely to express mutant TRIM37 proteins. These mutations were further shown to alter the subcellular localization of the mutant proteins. Most of the mulibrey nanism associated mutations however, lead to premature termination codons and degradation of mRNA. All the TRIM37 mutations identified to date predict loss-of-function alleles, and thus no phenotype-genotype correlation is seen among the patients. In order to understand the pathogenetic mechanisms underlying mulibrey nanism, an animal model for the disorder is needed. For the development of a Trim37 knock-out mouse, the mouse Trim37 gene was characterized. Alternative splice variants, were identified, including a testis specific variant predicting a longer protein product. Further, a strictly tissue and cell-specific pattern of Trim37 expression was observed in developing and adult mouse tissues, when studied by immunohistochemical methods. This distribution of Trim37 expression in mouse tissues is in agreement with the clinical findings in human mulibrey nanism patients. This thesis work gives new tools for the diagnostics of mulibrey nanism as well as for studying the molecular pathogenesis behind this interesting disorder.
Resumo:
In the yeast, mobilization of triacylglycerols (TAG) is facilitated by TGL3, TGL4 and TGL5 gene products. Interestingly, experiments using [32P] orthophosphate as a precursor for complex glycerophospholipids revealed that tgl mutants had a lower steady-state level of these membrane lipids. To understand a possible link between TAG lipolysis and phospholipid metabolism, we performed overexpression studies with Tgl3p and Tgl5p which clearly demonstrated that these two enzymes enhanced the level of phospholipids. Domains and motifs search analyses indicated that yeast TAG hydrolases posses a GXSXG lipase motif but also a HX4D acyltransferase motif. Purified Tgl3p and Tgl5p did not only exhibit TAG lipase activity but also catalyzed acyl-CoA dependent acylation of lyso-phosphatidylethanolamine and lyso-phosphatidic acid (LPA), respectively. Search for lipase/hydrolase homologues in the Arabidopsis thaliana genome led to the identification of At4g24160 which possess three motifs that are conserved across the plant species such as GXSXG motif, a HX4D motif and a probable lipid binding motif V(X)3HGF. Characterization of At4g24160 expressed in bacteria revealed that the presence of an acyl-CoA dependent LPA acyltransferase activity. In addition, the purified recombinant At4g24160 protein hydrolyzed both TAG and phosphatidylcholine. We hypothesize that the plant enzyme may be involved in membrane repair. In summary, our results indicate that these TAG lipases play a dual role and thereby contribute to both anabolic and catabolic processes in yeast and plants.
Resumo:
Obverse: In the center, the arch which served as an entrance to the Acropolis during the historical periods, to the left columns of different sizes, leaves and branches-motif from Nabatean bowl from Avdat, replica of astone relief motif from the late Roman period representing a bird. Reverse: Avdat coin minted by Nabatean King Aretas IV, in the center of the coin with a double cornucopia crossed at its base.
Resumo:
Mxr1p (methanol expression regulator 1) functions as a key regulator of methanol metabolism in the methylotrophic yeast Pichia pastoris. In this study, a recombinant Mxr1p protein containing the N-terminal zinc finger DNA binding domain was overexpressed and purified from E coli cells and its ability to bind to promoter sequences of AOXI encoding alcohol oxidase was examined. In the AOXI promoter, Mxr1p binds at six different regions. Deletions encompassing these regions result in a significant decrease in AOXI promoter activity in vivo. Based on the analysis of AOXI promoter sequences, a consensus sequence for Mxr1p binding consisting of a core 5' CYCC 3' motif was identified. When the core CYCC sequence is mutated to CYCA, CYCT or CYCM (M = 5-methylcytosine), Mxr1p binding is abolished. Though Mxr1p is the homologue of Saccharomyces cerevisiae Adr1p transcription factor, it does not bind to Adr1p binding site of S. cerevisiae alcohol dehydrogenase promoter (ADH2UAS1). However, two point mutations convert ADH2UAS1 into an Mxr1p binding site. The identification of key DNA elements involved in promoter recognition by Mxr1p is an important step in understanding its function as a master regulator of the methanol utilization pathway in P. pastoris.