Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Keywords: EXPRESSION ; Germany ; SITE ; SITES ; GENE ; GENE-EXPRESSION ; GENES ; GENOME SEQUENCE ; PROTEIN ; CONTRAST ; ACID ; gene expression ; EFFICACY ; CONSERVATION ; Jun ; SELECTION ; nutrition ; PHYLOGENETIC ANALYSIS ; REQUIREMENT ; AMINO-ACID ; CODON ; HIGH EXPRESSION ; APHIDS ; Blochmannia ; Buchnera ; insects ; NONSYNONYMOUS SUBSTITUTION ; substitution rates ; SYMBIONT ; WIGGLESWORTHIA
    Abstract: Most endosymbiotic bacteria have extremely reduced genomes, accelerated evolutionary rates, and strong AT base compositional bias thought to reflect reduced efficacy of selection and increased mutational pressure. Here, we present a comparative study of evolutionary forces shaping five fully sequenced bacterial endosymbionts of insects. The results of this study were three-fold: (i) Stronger conservation of high expression genes at not just nonsynonymous, but also synonymous, sites. (ii) Variation in amino acid usage strongly correlates with GC content and expression level of genes. This pattern is largely explained by greater conservation of high expression genes, leading to their higher GC content. However, we also found indication of selection favoring GC-rich amino acids that contrasts with former studies. (iii) Although the specific nutritional requirements of the insect host are known to affect gene content of endosymbionts, we found no detectable influence on substitution rates, amino acid usage, or codon usage of bacterial genes involved in host nutrition. (c) 2005 Elsevier B.V. All rights reserved
    Type of Publication: Journal article published
    PubMed ID: 15935576
    Signatur Availability
    BibTip Others were also interested in ...
  • 2
    Keywords: CELLS ; EXPRESSION ; Germany ; human ; CDNA CLONES ; GENE ; GENES ; GENOME ; HYBRIDIZATION ; PROTEIN ; PROTEINS ; transcription ; data mining ; radiation ; murine ; FAMILY ; MEMBER ; SEQUENCE ; TRANSPORT ; MOUSE ; IN-SITU ; YEAST ; MEMBRANE ; REQUIRES ; AAA family ; DATABASE ; DISPLAY ; endocytosis ; ENDOSOMAL TRAFFICKING ; FISH ; FUSION PROTEINS ; HUMAN GENOME ; INTRACELLULAR PROTEIN TRAFFICKING ; LATE-GOLGI ; MOUSE SKD1 ; MULTIVESICULAR BODY ; TRAFFICKING ; vacuolar protein sorting ; VPS4- paralogue
    Abstract: The VPS4 gene is a member of the AAA-family; it codes for an ATPase which is involved in lysosomal/endosomal membrane trafficking. VPS4 genes are present in virtually all eukaryotes. Exhaustive data mining of all available genomic databases from completely or partially sequenced organisms revealed the existence of up to three paralogues, VPS4a, -b, and -c. Whereas in the genome of lower eukaryotes like yeast only one VPS4 representative is present, we found that mammals harbour two paralogues, VPS4a and VPS4b. Most interestingly, the Fugu fish contains a third VPS4 paralogue (VPS4c). Sequence comparison of the three VPS4 paralogues indicates that the Fugu VPS4c displays sequence features intermediate between VPS4a and VPS4b. Using complete mammalian VPS4a and VPS4b cDNA clones as probes, genomic clones of both VPS4 paralogues in human and mouse were identified and sequenced. The chromosomal loci of all four VPS4 genes were determined by independent methods. A BLAST search of the human genome database with the human VPS4A sequence yielded a double match, most likely due to a faulty assembly of sequence contigs in the human draft sequence. Fluorescent in situ hybridization and radiation hybrid analyses demonstrated that human and mouse VPS4A/a and VPS4B/b are located on syntenic chromosomal regions. Northern blot and semi-quantitative reverse transcription analyses showed that mouse VPS4a and VPS4b are differentially expressed in different organs, suggesting that the two paralogues have developed different functional properties since their divergence. To investigate the subcellular distribution of the murine VPS4 paralogues, we transiently expressed various fluorescent VPS4 fusion proteins in mouse 3T3 cells. All tested VPS4 fusion proteins were found in the cytosol. Expression of dominant- negative mutant VPS4 fusion proteins led to their concentration in the perinuclear region. Co-expression of VPS4a-GFP and VPS4b-dsRed fusion proteins revealed a partial co-localization that was most prominent with mutant VPS4a and VPS4b proteins. A physical interaction between the mouse paralogues was also supported by two-hybrid analyses. (C) 2003 Elsevier Science B.V. All rights reserved
    Type of Publication: Journal article published
    PubMed ID: 12594041
    Signatur Availability
    BibTip Others were also interested in ...
  • 3
    facet.materialart.
    facet.materialart.
    Gene 302 (1-2), 179-183 
    Keywords: RECEPTOR ; INHIBITOR ; Germany ; human ; INHIBITION ; GENE ; PROTEIN ; PROTEINS ; LIGAND ; FAMILY ; DOMAIN ; BINDING ; fibroblasts ; SIGNALING PATHWAY ; EMBRYO ; XENOPUS ; dkk1 ; beta-catenin ; ANTAGONIST ; BINDS ; dkk2 ; dkk3 ; dkk4 ; low density lipoprotein receptor related protein ; SECRETED PROTEINS ; SPEMANN ORGANIZER ; WNT ; Wnt antagonist
    Abstract: Dickkopf 1 (Dkk 1) is a secreted antagonist of the Wnt/beta- catenin signaling pathway that acts by direct binding to and inhibiting the Wnt coreceptor LRP6. The related Dkk2, however, can function either as LRP6 agonist or antagonist, depending on the cellular context, suggesting that its activity is modulated by unknown co-factors. We have recently identified the transmembrane proteins Kremen 1 and -2 as additional Dkk receptors, which bind to both Dkk I and Dkk2 with high affinity. Here we show that Kremen2 (Krm2) regulates Dkk2 activity during Wnt signaling. In human 293 fibroblasts transfected dkk2 activates LRP6 signaling. However, co- transfection of krm2 blocks the ability of Dkk2 to activate LRP6 and enhances inhibition of Wnt/Frizzled signaling. Krm2 also co-operates with Dkk4 to inhibit Wnt signaling, but not with Dkk3, which has no effect on Wnt signaling. Likewise, in Xenopus embryos, Dkk2 and Krm2 co-operate in Wnt inhibition leading to anteriorized embryos. Finally, we show that the interaction with Krm2 is mediated by the second cysteine-rich domain of Dkks. These results suggest that Krm2 can function as a switch that turns Dkk2 from an activator into an inhibitor of Wnt/1RP6 signaling. (C) 2002 Elsevier Science B.V. All rights reserved
    Type of Publication: Journal article published
    PubMed ID: 12527209
    Signatur Availability
    BibTip Others were also interested in ...
  • 4
    Keywords: CELLS ; CELL ; Germany ; human ; GENERATION ; SUPPORT ; GENE ; PROTEIN ; cell line ; LINES ; COMPLEX ; COMPLEXES ; murine ; MARKER ; recombination ; CELL-LINES ; TARGET ; DELETION ; knockout ; IDENTIFICATION ; YEAST ; DISRUPTION ; VECTORS ; VECTOR ; NUMBER ; CELL-LINE ; LINE ; EFFICIENT ; MARKERS ; MAMMALIAN-CELLS ; STEM-CELLS ; STRATEGIES ; DNA-REPLICATION ; SELECTION ; EPSTEIN-BARR-VIRUS ; HOMOLOGOUS RECOMBINATION ; ORIGIN ; INTEGRATION ; targeting ; Epstein-Barr virus ; RECOMBINANT ; ALLELE ; TRANSFECTION ; gene targeting ; LYTIC ORIGIN
    Abstract: Among the different approaches used to define the function of a protein of interest, alteration and/or deletion of its encoding gene is the most direct strategy. Homologous recombination between the chromosomal gene locus and an appropriately designed targeting vector results in an alteration or knockout of the gene of interest. Homologous recombination is easily performed in yeast or in murine embryonic stem cells, but is cumbersome in more differentiated and diploid somatic cell lines. Here we describe an efficient method for targeting both alleles of a complex human gene locus in DG75 cells, a cell line of lymphoid origin. The experimental approach included a conditional knockout strategy with three genotypic markers, which greatly facilitated the generation and phenotypic identification of targeted recombinant cells. The vector was designed such that it could be reused for two consecutive rounds of recombination to target both alleles. The human DG75 cell line appears similar to the chicken DT40 pre B-cell line, which supports efficient homologous recombination. Therefore, the DG75 cell line is a favorable addition to the limited number of cell lines amenable to gene targeting and should prove useful for studying gene function through targeted gene alteration or deletion in human somatic cells. (C) 2004 Elsevier B.V. All rights reserved
    Type of Publication: Journal article published
    PubMed ID: 15563834
    Signatur Availability
    BibTip Others were also interested in ...
  • 5
    Keywords: brain ; RECEPTOR ; SPECTRA ; EXPRESSION ; tumor ; human ; LUNG-CANCER ; GENE ; PROTEIN ; RNA ; MOLECULAR CHARACTERIZATION ; TISSUE ; TUMORS ; pig ; DOMAIN ; TISSUES ; CONTRAST ; BINDING ; OPEN READING FRAME ; SEQUENCE ; polymorphism ; VARIANTS ; ACID ; ACIDS ; ENCODES ; HUMANS ; NUMBER ; EPITHELIAL-CELLS ; RT-PCR ; AMINO-ACIDS ; DOMAINS ; TERMINAL DIFFERENTIATION ; DMBT1 ; SALIVARY AGGLUTININ ; SCAVENGER RECEPTOR ; BRAIN-TUMORS ; VARIANT ; TUMORIGENESIS ; SWITZERLAND ; brain tumors ; LEVEL ; SIZE ; genomic ; NORTHERN ; BACTERIA-BINDING ; CYSTEINE-RICH DOMAINS ; segmental duplication ; SRCR SUPERFAMILY
    Abstract: The human gene deleted in malignant brain tumors 1 (DMBT1) is considered to play a role in tumorigenesis and pathogen defense. It encodes a protein with multiple scavenger receptor cysteine-rich (SRCR) domains, which are involved in recognition and binding of a broad spectrum of bacterial pathogens. The SRCR domains are encoded by highly homologous repetitive exons, whose number in humans may vary from 8 to 13 due to genetic polymorphism. Here, we characterized the porcine DMBTI gene on the mRNA and genomic level. We assembled a 4.5 kb porcine DMBT1 cDNA sequence from RT-PCR amplified seminal vesicle RNA. The porcine DMBT1 cDNA contains an open reading frame of 4050 nt. The transcript gives rise to a putative polypeptide of 1349 amino acids with a calculated mass of 147.9 kDa. Compared to human DMBT1, it contains only four N-terminal SRCR domains. Northern blotting revealed transcripts of similar to 4.7 kb in size in the tissues analyzed. Analysis of ESTs suggested the existence of secreted and transmembrane variants. The porcine DMBT1 gene spans about 54 kb on chromosome 14q28-q29. In contrast to the characterized cDNA, the genomic BAC clone only contained 3 exons coding for N-terminal SRCR domains. In different mammalian DMBT1 orthologs large interspecific differences in the number of SRCR exons and utilization of the transmembrane exon exist. Our data suggest that the porcine DMBT1 gene may share with the human DMBT1 gene additional intraspecific variations in the number of SRCR-coding exons. (c) 2006 Elsevier B.V. All rights reserved
    Type of Publication: Journal article published
    PubMed ID: 16624504
    Signatur Availability
    BibTip Others were also interested in ...
  • 6
    Keywords: Germany ; human ; GENE ; GENES ; GENOME ; PROTEIN ; PROTEINS ; transcription ; FAMILY ; TRANSCRIPTION FACTOR ; DOMAIN ; SEQUENCE ; MOUSE ; IDENTIFICATION ; NUCLEAR-FACTOR ; PATTERNS ; DNA-BINDING ; PRODUCT ; LOCALIZATION ; REPLICATION ; exon-intron structure ; ADENOVIRUS DNA ; alternative splicing ; CHICKEN ; CHROMOSOMAL LOCALIZATION ; chromosomal mapping ; FACTOR-I ; FAIR ; fluorescence in situ hybridization ; NFI-X ; nuclear factor I ; TGGCA PROTEIN
    Abstract: Transcription factor Nuclear Factor One (NFI) proteins are derived from a small family of four vertebrate genes (NFIA, B, C and X), all of which produce a fair number of protein variants by alternative splicing. In order to ultimately locate RNA signal sequences around exon/intron borders for the production of regulated splice variants, we have determined the exon structure of the chicken NFIB gene as the last of the four vertebrate genes for which the gene structure was not yet elucidated. This made it possible to compile nine newly isolated and sequenced mouse NFI cDNA sequences together with all previously available ones and to deduce corresponding splicing patterns for the orthologous vertebrate genes of all four paralogous gene types. Results from the analysis of alternative splicing and of NFI gene mapping in the genome of human and mouse argue for a phylogenetic route in which the four vertebrate NFI genes result from a single duplication of a genomic segment containing two NFI intermediate genes rather than from two independent duplications of two separated single ancestor genes. (C) 2002 Elsevier Science B.V. All rights reserved
    Type of Publication: Journal article published
    PubMed ID: 12568726
    Signatur Availability
    BibTip Others were also interested in ...
  • 7
    Keywords: CELLS ; EXPRESSION ; CELL ; Germany ; human ; COMMON ; SYSTEM ; GENE ; PROTEIN ; PROTEINS ; MOLECULAR CHARACTERIZATION ; FAMILY ; PROTEIN FAMILIES ; PROTEIN FAMILY ; CYCLE ; NERVOUS-SYSTEM ; HUMANS ; EVOLUTION ; LOCALIZATION ; STEM-CELLS ; NETHERLANDS ; OF-FUNCTION ; ORIGIN ; PATTERN ; CIRCADIAN OUTPUT ; ECHINATA ; FMR1 ; FMRP ; FXR ; FXR2 ; Hydractinia ; HYDROID HYDRACTINIA ; hydrozoa ; LIFE-CYCLE ; NEURONS ; RIBOSOMES ; RNA-BINDING ; RNA-BINDING PROTEIN ; TRANSLATION
    Abstract: The fragile X mental retardation syndrome in humans is caused by a mutational loss of function of the fragile X mental retardation gene 1 (FMR1). FMR1 is an RNA-binding protein, involved in the development and function of the nervous system. Despite of its medical significance, the evolutionary origin of FMR1 has been unclear. Here, we report the molecular characterization of HyFMR1, an FMR1 orthologue, from the cnidarian hydroid Hydractinia echinata. Cnidarians are the most basal metazoans possessing neurons. HyFMR1 is expressed throughout the life cycle of Hydractinia. Its expression pattern correlates to the position of neurons and their precursor stem cells in the animal. Our data indicate that the origin of the fraxile X related (FXR) protein family dates back at least to the common ancestor of cnidarians and bilaterians. The lack of FXR proteins in other invertebrates may have been due to gene loss in particular lineages. (C) 2004 Elsevier B.V. All rights reserved
    Type of Publication: Journal article published
    Signatur Availability
    BibTip Others were also interested in ...
  • 8
    Keywords: APOPTOSIS ; CELLS ; EXPRESSION ; GROWTH ; INVASION ; proliferation ; tumor ; CELL ; Germany ; human ; SITE ; DISTINCT ; GENE ; GENE-EXPRESSION ; TUMORS ; ACTIVATION ; TRANSCRIPTION FACTOR ; AP-1 ; INDUCTION ; BINDING ; CLEAVAGE ; DELETION ; CHROMATIN ; gene expression ; DISRUPTION ; Drosophila ; PROMOTER ; MUTATION ; genetics ; REGION ; MIGRATION ; STABILITY ; HEAD ; NETHERLANDS ; CELL-MIGRATION ; heredity ; TRANSCRIPTIONAL REGULATION ; RE ; HELA-CELLS ; SOLID TUMORS ; mRNA ; HETERODIMER ; analysis ; CHIP ; EXTENT ; UPSTREAM ; biological ; Activator Protein 1 (AP-1) ; calpain - cysteine protease ; CAPNS1 gene ; chromatin immunoprecipitation ; ECTOPIC EXPRESSION ; EUKARYOTIC INITIATION FACTOR-2-ALPHA ; M-CALPAIN ; nuclear respiratory factor 1 (NRF-1) ; promoter analysis ; SIRNA ; SMALL-SUBUNIT ; Sp1 binding site
    Abstract: Ubiquitously expressed mu- and m-calpain are cysteine proteases, with broad functions in cell spreading, migration, proliferation, apoptosis, and in tumor invasion. They are heterodimers, with a distinct large 80-kDa catalytic, and a common small 28-kDa regulatory subunit (Capn4/CAPNS1). CAPNS1 is required to maintain stability and activity of both calpains. Despite its biological importance, the transcriptional regulation of this gene has not been studied, and the CAPNS1 promoter has not yet been characterized. In this study, we identified the main transcriptional start site, and cloned and characterized the similar to 2.0 kb upstream region of the CAPNS1 gene. Deletion analysis identified the core promoter located within region -187/+174. Site-directed mutagenesis, EMSA- and supershift analysis identified Sp1-, NRF-1-, and AP-1-binding elements within the CAPNS1 core promoter. Binding of NRF-1, Sp1 and AP-1 to the natural core promoter was confirmed by chromatin immunoprecipitation (ChIP). Site-directed mutagenesis at the NRF-1 site in HeLa and MCF7 cells substantially reduced core promoter activity by 70%, whereas mutation of the AP-1-binding and Sp1-binding site reduced promoter activity by 50% and 30%, respectively. Double mutation of the NRF-1 and the AP-1 site reduced promoter activity by 90%. In Drosophila SL2 cells, ectopic expression of NRF-1 led to a significant induction of CAPNS1 promoter activity. Furthermore, an siRNA against NRF-1 substantially reduced promoter activity in HeLa cells, which was paralleled by a significant downregulation of CAPNS1 mRNA. These results reveal that especially NRF-1, along with AP-1 and, to a minor extent, an Sp1 site, is essential for human CAPNS1 promoter activity and gene expression. (C) 2007 Elsevier B.V. All rights reserved
    Type of Publication: Journal article published
    PubMed ID: 18234454
    Signatur Availability
    BibTip Others were also interested in ...
  • 9
    Keywords: CELLS ; EXPRESSION ; CELL ; Germany ; human ; GENERATION ; SYSTEM ; SYSTEMS ; GENE ; microarray ; RNA ; transcription ; cell line ; gene therapy ; LINES ; CELL-LINES ; SEQUENCE ; SEQUENCES ; PARTICLES ; virus ; VECTOR ; genetics ; CELL-LINE ; leukemia ; LINE ; retroviral vector ; RETROVIRAL VECTORS ; cell lines ; heredity ; HUMAN-IMMUNODEFICIENCY-VIRUS ; TRANSCRIPTS ; RE ; VESICLES ; HIV ; PROFILES ; PLASMID ; IMMUNODEFICIENCY VIRUS ; packaging ; LEUKEMIA-VIRUS ; exosome ; exosomes ; copackaging ; DNA chip ; HERV ; human endogenous retroviruses ; packaging cell line
    Abstract: Using a versatile and highly sensitive retroviral microarray, we have investigated particle preparations from three different human packaging cell lines harboring retroviral vector systems based on human immunodeficiency virus (HIV) and murine leukemia virus (MLV). 293Rev/Gag/Pol(i) cells inducibly express high titers of HIV-derived particles for packaging of HIV vectors. The Phoenix-GP and the Anjou 65 cell lines constitutively express MLV vector particles. We compared the transcription profiles of human endogenous retroviruses (HERVs) in all cell lines with the HERV sequences present in the particles. In addition, the influence of the transfected vector plasmid on the copackaging of HERVs was investigated. All particle preparations showed a defined pattern of endogenous retroviral sequences that differed from the cellular HERV expression pattern. HERV transcripts were observed in the particle preparations independent of whether a vector construct was coexpressed or not. Furthermore, our results suggest that particle preparations are frequently contaminated by cellular vesicles (exosomes) containing cellular RNAs including HERV transcripts. (c) 2006 Elsevier B.V. All rights reserved
    Type of Publication: Journal article published
    PubMed ID: 17045761
    Signatur Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Gene 25 (1983), S. 361-364 
    ISSN: 0378-1119
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...