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931.
Lucas Spohn Christiane Fichter Martin Werner Silke Lassmann 《Journal of cell communication and signaling》2016,10(1):41-47
Background: The EGF receptor is a therapeutic target in cancer cells, whereby mutations of EGFR and/or signalling members act as predictive markers. EGFR however also exhibits dynamic changes of subcellular localization, leading to STAT5 complex formation, nuclear translocation and induction of Aurora-A expression in squamous cancer cells. We previously described high EGFR and Aurora-A expression in esophageal cancer cells. Here, we investigated subcellular localization of EGFR and STAT5 in esophageal cancer cells. Results: Quantitative immunofluorescence analyses of four esophageal cancer cell lines reflecting esophageal squamous cell carcinomas (ESCC) and esophageal adenocarcinomas (EAC) revealed that the subcellular localization of EGFR was shifted from a membranous to cytoplasmic localization upon EGF-stimulation in OE21 (ESCC) cells. Thereby, EGFR in part co-localized with E-Cadherin. In parallel, phosphorylated STAT5-Tyr694 appeared to increase in the nucleus and to decrease at the cell membrane. In three additional cell lines, EGFR was only marginally (Kyse-410/ESCC; OE19/EAC) and weakly (OE33, EAC) detectable at the cell membrane. Partial co-localization of EGFR and E-Cadherin occurred in OE33 cells. Post EGF-stimulation, EGFR was detected in the cytoplasm, resembling endosomal compartments. Furthermore, OE19 and OE33 exhibited nuclear STAT5-Tyr694 phosphorylation upon EGF-stimulation. None of the four cell lines showed nuclear EGFR expression and localization. Conclusion: In contrast to other (squamous) cancer cells, activation of EGFR in esophageal squamous cancer cells does not result in nuclear translocation of EGFR. Still, the subcellular localization of EGFR may influence STAT5-associated signaling pathways in esophageal cancer cells and hence possibly also the responses to ErbB, respective EGFR-targeted therapies. 相似文献
932.
933.
Se Ryun Kwon Yue Jai Kang Dong Jin Lee Eun Hye Lee Yoon Kwon Nam Sung Koo Kim Ki Hong Kim 《Molecular biotechnology》2009,42(2):154-159
Vibrio anguillarum ghosts (VAG) were generated, for the first time, using a conjugation vector containing a ghost bacteria inducing cassette,
pRK-λPR-cI-Elysis, in which the expression of PhiX174 lysis gene E was controlled by the P
R
/cI regulatory system of lambda phage. By scanning electron microscopy, holes ranging 80–200 nm in diameter were observed in
the VAG. To avoid the presence of bacterial genomic DNA and an antibiotic resistance gene in the final VAG product, we constructed
a new dual vector, pRK-λPR-cI-E-SNA, containing the E-mediated lysis cassette and the staphylococcal nuclease A (SNA)-mediated DNA degradation cassette, and generated safety-enhanced VAG for use as a fish vaccine. 相似文献
934.
Kai-Shu Ling Karen R. Harris Jenelle D. F. Meyer Amnon Levi Nihat Guner Todd C. Wehner Abdelhafid Bendahmane Michael J. Havey 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,120(1):191-200
Zucchini yellow mosaic virus (ZYMV) is one of the most economically important potyviruses infecting cucurbit crops worldwide. Using a candidate gene approach,
we cloned and sequenced eIF4E and eIF(iso)4E gene segments in watermelon. Analysis of the nucleotide sequences between the
ZYMV-resistant watermelon plant introduction PI 595203 (Citrullus lanatus var. lanatus) and the ZYMV-susceptible watermelon cultivar ‘New Hampshire Midget’ (‘NHM’) showed the presence of single nucleotide polymorphisms
(SNPs). Initial analysis of the identified SNPs in association studies indicated that SNPs in the eIF4E, but not eIF(iso)4E,
were closely associated to the phenotype of ZYMV-resistance in 70 F2 and 114 BC1R progenies. Subsequently, we focused our efforts in obtaining the entire genomic sequence of watermelon eIF4E. Three SNPs
were identified between PI 595203 and NHM. One of the SNPs (A241C) was in exon 1 and the other two SNPs (C309A and T554G)
were in the first intron of the gene. SNP241 which resulted in an amino acid substitution (proline to threonine) was shown
to be located in the critical cap recognition and binding area, similar to that of several plant species resistance to potyviruses.
Analysis of a cleaved amplified polymorphism sequence (CAPS) marker derived from this SNP in F2 and BC1R populations demonstrated a cosegregation between the CAPS-2 marker and their ZYMV resistance or susceptibility phenotype.
When we investigated whether such SNP mutation in the eIF4E was also conserved in several other PIs of C. lanatus var. citroides, we identified a different SNP (A171G) resulting in another amino acid substitution (D71G) from four ZYMV-resistant C. lanatus var. citroides (PI 244018, PI 482261, PI 482299, and PI 482322). Additional CAPS markers were also identified. Availability of all these
CAPS markers will enable marker-aided breeding of watermelon for ZYMV resistance. 相似文献
935.
Peter Roessingh Sen Xu Steph B. J. Menken 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2007,193(6):635-647
In lepidopterous larvae the maxillary palps contain a large portion of the sensory equipment of the insect. Yet, knowledge
about the sensitivity of these cells is limited. In this paper a morphological, behavioral, and electrophysiological investigation
of the maxillary palps of Yponomeuta cagnagellus (Lepidoptera: Yponomeutidae) is presented. In addition to thermoreceptors, CO2 receptors, and gustatory receptors, evidence is reported for the existence of two groups of receptor cells sensitive to plant
volatiles. Cells that are mainly sensitive to (E)-2-hexenal and hexanal or to (Z)-3-hexen-1-ol and 1-hexanol were found. Interestingly, a high sensitivity for benzaldehyde was also found. This compound
is not known to be present in Euonymus europaeus, the host plant of the monophagous Yponomeuta cagnagellus, but it is a prominent compound in Rosaceae, the presumed hosts of the ancestors of Y. cagnagellus. To elucidate the evolutionary history of this sensitivity, and its possible role in host shifts, feeding responses of three
Yponomeuta species to benzaldehyde were investigated. The results confirm the hypothesis that the sensitivity to benzaldehyde evolved
during the ancestral shift from Celastraceae to Rosaceae and can be considered an evolutionary relict, retained in the recently
backshifted Celastraceae-specialist Y. cagnagellus. 相似文献
936.
Ascorbate (AsA) plays a fundamental role in redox homeostasis in plants and animals, primarily by scavenging reactive oxygen
species. Three genes, representing diverse steps putatively involved in plant AsA biosynthesis pathways, were cloned and independently
expressed in Solanum lycopersicum (tomato) under the control of the CaMV 35S promoter. Yeast-derived GDP-mannose pyrophosphorylase (GMPase) and arabinono-1,4-lactone oxidase (ALO), as well as myo-inositol oxygenase 2 (MIOX2) from Arabidopsis thaliana, were targeted. Increases in GMPase activity were concomitant with increased AsA levels of up to 70% in leaves, 50% in green
fruit, and 35% in red fruit. Expression of ALO significantly pulled biosynthetic flux towards AsA in leaves and green fruit by up to 54 and 25%, respectively. Changes in
AsA content in plants transcribing the MIOX2 gene were inconsistent in different tissue. On the other hand, MIOX activity was strongly correlated with cell wall uronic
acid levels, suggesting that MIOX may be a useful tool for the manipulation of cell wall composition. In conclusion, the Smirnoff–Wheeler
pathway showed great promise as a target for biotechnological manipulation of ascorbate levels in tomato. 相似文献
937.
Four different bacterial isolates obtained from a stable bacterial consortium were capable of utilizing pentachlorophenol
(PCP) as sole carbon and energy source. The consortium was developed by continuous enrichment in the chemostat. The degradation
of PCP by bacterial strain was preceded through an oxidative route as indicated by accumulation of tetrachloro-ρ-hydroquinone
and dichlorohydroquinone as determined by high performance liquid chromatography (HPLC). Among the four isolates, Pseudomonas fluorescens exhibited maximum degradation capability and enzyme production. PCP-monooxygenase enzyme was extracted from culture extract
and fractionated by DEAE-cellulose ion exchange chromatography. The molecular weight of the enzyme, purified from Pseudomonas fluorescens, determined by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and gel filtration chromatography was
found to be 24,000 Da.
Received: 22 July 2002 / Accepted: 23 September 2002 相似文献
938.
Andrea M. Stancin James D. Gleason Steven A. Hovan David K. Rea Robert M. Owen Theodore C. Moore Jr. Chris M. Hall Joel D. Blum 《Palaeogeography, Palaeoclimatology, Palaeoecology》2008,261(3-4):218-233
A 14-meter long pelagic clay core recovered at Marlin Rise (40°00.531′S, 154°2.601′W; 4775 m water depth) in the Southwest Pacific Basin contains a record of eolian dust deposited since the early Miocene. Downcore analysis of detrital minerals reveals a dominantly eolian signature with relatively constant proportions of quartz, feldspar and illite and trace amounts of chlorite, kaolinite and smectite, consistent with a continental (loess-like) source region. Fish tooth Sr isotope stratigraphy reveals the base of the core to be 17.5 Ma, with low sedimentation rates (< 0.5 mm/kyr LSR) indicated for the interval 17.5 to 10 Ma; several hiatuses in deposition appear to be present upcore, but are beyond the age resolution of the fish teeth stratigraphy. These intervals are revealed as apparent discontinuities in the Sr isotope record, accompanied by pulses of anomalously rapid sedimentation at ~ 10 Ma, 6.7 Ma and 4.1 Ma. Bulk mass accumulation rates (MAR) are calculated at ~ 10 mg/cm2/kyr over the last 4 Myr, consistent with previously estimated Quaternary eolian flux rates to this part of the Pacific. Nd, Pb and Sr radiogenic isotopic compositions of the detrital mineral extract (< 38 µm) show no trends with age, while 40Ar/39Ar ages show an upcore younging trend (~180 Ma to ~150 Ma), in concert with a slight coarsening of eolian grain-size distributions. These ages likely reflect mixing of Mesozoic illite-dominated clay from at least two continental source areas: southeastern Australia (Murray–Darling Basin/Lake Eyre Basin) and New Zealand (South Island). The data indicate remarkable constancy of continental eolian sources exposed to weathering and dispersal at this latitude during the Neogene. 相似文献
939.
Don A. Driscoll Annabel L. Smith Samantha Blight John Maindonald 《Biodiversity and Conservation》2012,21(6):1607-1625
Altered fire regimes are a driver of biodiversity decline. To plan effective management, we need to know how species are influenced
by fire and to develop theory describing fire responses. Animal responses to fire are usually measured using methods that
rely on animal activity, but animal activity may vary with time since fire, potentially biasing results. Using a novel approach
for detecting bias in the pit-fall trap method, we found that leaf-litter dependent reptiles were more active up to 6 weeks
after fire, giving a misleading impression of abundance. This effect was not discovered when modelling detectability with
zero-inflated binomial models. Two species without detection bias showed early-successional responses to time since fire,
consistent with a habitat-accommodation succession model. However, a habitat specialist did not have the predicted low abundance
after fire due to increased post-fire movement and non-linear recovery of a key habitat component. Interactions between fire
and other processes therefore must be better understood to predict reptile responses to changing fire-regimes. We conclude
that there is substantial bias when trapping reptiles after fire, with species that are otherwise hard to detect appearing
to be abundant. Studies that use a survey method based on animal activity such as bird calls or animal movements, likely face
a similar risk of bias when comparing recently-disturbed with control sites. 相似文献
940.
Kawakami N Lee JM Mon H Kubo Y Banno Y Kawaguchi Y Maenaka K Park EY Koga K Kusakabe T 《Molecular biotechnology》2008,40(2):180-185
The recombinant protein expression by Bombyx mori nucleopolyhedrovirus (BmNPV) infecting silkworm larvae or pupae may endow us with a potent system for the production of large
eukaryotic proteins. However, the screening of silkworm strains ideally suited to this method has scarcely been conducted.
In the present study, we injected recombinant BmNPV containing a reporter gene, luciferase or DsRed, into hemocoel of fifth
instar larvae of selected 12 silkworm strains. Among them, the strain d17 is found to be the highest in reporter expression
from the intrinsic polyhedrin promoter of Autographa californica NPV or the silkworm actin A3 promoter. These results suggest that the d17 strain is highly permissive for BmNPV replication
and is the most likely candidate of a “factory” for large-scale expression using the BmNPV bacmid system. 相似文献