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51.
52.
G H Wabnitz C Goursot B Jahraus H Kirchgessner A Hellwig M Klemke M H Konstandin Y Samstag 《Cell death & disease》2010,1(7):e58
Oxidative stress leads to T-cell hyporesponsiveness or death. The actin-binding protein cofilin is oxidized during oxidative stress, which provokes a stiff actin cytoskeleton and T-cell hyporesponsiveness. Here, we show that long-term oxidative stress leads to translocation of cofilin into the mitochondria and necrotic-like programmed cell death (PCD) in human T cells. Notably, cofilin mutants that functionally mimic oxidation by a single mutation at oxidation-sensitive cysteins (Cys-39 or Cys-80) predominately localize within the mitochondria. The expression of these mutants alone ultimately leads to necrotic-like PCD in T cells. Accordingly, cofilin knockdown partially protects T cells from the fatal effects of long-term oxidative stress. Thus, we introduce the oxidation and mitochondrial localization of cofilin as the checkpoint for necrotic-like PCD upon oxidative stress as it occurs, for example, in tumor environments. 相似文献
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Application of cDNA arrays to monitor mRNA profiles in single preimplantation mouse embryos 总被引:5,自引:0,他引:5
Brambrink T Wabnitz P Halter R Klocke R Carnwath J Kues W Wrenzycki C Paul D Niemann H 《BioTechniques》2002,33(2):376-8, 380, 382-5
Array technology is a widely used tool for gene expression profiling in various biological systems. However, the application of this method to mammalian preimplantation embryos is limited by the small amount of mRNA that can be extracted from a single embryo, which is not sufficient for array analysis. Here we report a protocolfor the rapid global amplification of embryonic mRNA that permits the generation of expression profiles from single murine blastocysts. The approach combines global PCR and 77 RNA polymerase amplification and allows the preparation of labeled, amplified RNA for array hybridization from single murine blastocysts containing approximately 1.5 pg mRNA in less than 12 h. We demonstrate that this amplification procedure is highly reproducible and does not bias original relative mRNA levels. Signal patterns from various embryonic stages of murine development revealed marked differences in mRNA expression that were in accordance with previously published data. We found genes known to be involved in embryonic apoptosis expressed at different levels in individual murine day 3.5 blastocysts. This technique can thus be used to assess embryonic viability and investigate molecular mechanisms of embryonic development. 相似文献
55.
Howe GT; Bucciaglia PA; Hackett WP; Furnier GR; Cordonnier-Pratt MM; Gardner G 《Molecular biology and evolution》1998,15(2):160-175
The phytochrome photoreceptors play important roles in the photoperiodic
control of vegetative bud set, growth cessation, dormancy induction, and
cold-hardiness in trees. Interestingly, ecotypic differences in
photoperiodic responses are observed in many temperate- zone tree species.
Northern and southern ecotypes of black cottonwood (Populus trichocarpa
Torr. & Gray), for example, exhibit marked differences in the timing of
short-day-induced bud set and growth cessation, and these responses are
controlled by phytochrome. Therefore, as a first step toward determining
the molecular genetic basis of photoperiodic ecotypes in trees, we
characterized the phytochrome gene (PHY) family in black cottonwood. We
recovered fragments of one PHYA and two PHYB using PCR-based cloning and by
screening a genomic library. Results from Southern analyses confirmed that
black cottonwood has one PHYA locus and two PHYB loci, which we arbitrarily
designated PHYB1 and PHYB2. Phylogenetic analyses which included PHY from
black cottonwood, Arabidopsis thaliana and tomato (Solanum lycopersicum)
suggest that the PHYB/D duplications in these species occurred
independently. When Southern blots were probed with PHYC, PHYE, and PHYE
heterologous probes, the strongest bands that we detected were those of
black cottonwood PHYA and/or PHYB. These results suggest that black
cottonwood lacks members of the PHYC/F and PHYE subfamilies. Although black
cottonwood could contain additional PHY that are distantly related to known
angiosperm PHY, our results imply that the PHY family of black cottonwood
is less complex than that of other well-characterized dicot species such as
Arabidopsis and tomato. Based on Southern analyses of five black cottonwood
genotypes representing three photoperiodic ecotypes, substantial
polymorphism was detected for at least one of the PHYB loci but not for the
PHYA locus. The novel character of the PHY family in black cottonwood, as
well as the differences in polymorphism we observed between the PHYA and
PHYB subfamilies, indicates that a number of fundamental macro- and
microevolutionary questions remain to be answered about the PHY family in
dicots.
相似文献
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K L Wegener P A Wabnitz J A Carver J H Bowie B C Chia J C Wallace M J Tyler 《European journal of biochemistry》1999,265(2):627-637
Nineteen citropin peptides are present in the secretion from the granular dorsal glands of the Blue Mountains tree-frog Litoria citropa; 15 of these peptides are also present in the secretion from the submental gland. Two major peptides, citropin 1.1 (GLFDVIKKVASVIGGL-NH2), citropin 1.2 (GLFDIIKKVASVVGGL-NH2) and a minor peptide, citropin 1.3 (GLFDIIKKVASVIGGL-NH2) are wide-spectrum antibacterial peptides. The amphibian has an endoprotease which deactivates these membrane-active peptides by removing residues from the N-terminal end: loss of three residues gives the most abundant degradation products. The solution structure of the basic peptide citropin 1.1 has been determined by NMR spectroscopy [in a solvent mixture of trifluoroethanol/water (1 : 1)] to be an amphipathic alpha-helix with well-defined hydrophobic and hydrophilic regions. The additional four peptides produced by the dorsal glands are structurally related to the antibacterial citropin 1 peptides but contain three more residues at their C-terminus [e.g. citropin 1.1.3 (GLFDVIKKVASVIGLASP-OH)]. These peptides show minimal antibacterial activity; their role in the amphibian skin is not known. 相似文献
59.
Mice of the TO Swiss strain received diets containing different amounts of saturated or unsaturated fat throughout life. These diets produced characteristic changes in cardiac phospholipid fatty acid composition, but produced no significant differences in fatty acid composition of phospholipids from a crude membrane fraction of brain. When littermates of these animals were exposed to ethanol vapour in an inhalation chamber it was observed that mice which had received a diet high in saturated fat lost the righting reflex at an estimated concentration of ethanol in blood higher than that required for mice receiving a control diet, or a diet rich in polyunsaturated fat. Analysis of the brain membrane fraction from those animals which had received ethanol revealed that mice receiving the highly saturated fat diet now had a significantly greater proportion of saturated fatty acids in brain membrane phospholipids. These results are discussed in relation to the hypothesis that brain membrane lipid composition may influence the behavioural response to ethanol. 相似文献
60.
Sze SH; Roytberg MA; Gelfand MS; Mironov AA; Astakhova TV; Pevzner PA 《Bioinformatics (Oxford, England)》1998,14(1):14-19
MOTIVATION: Gene annotation is the final goal of gene prediction
algorithms. However, these algorithms frequently make mistakes and
therefore the use of gene predictions for sequence annotation is hardly
possible. As a result, biologists are forced to conduct time-consuming gene
identification experiments by designing appropriate PCR primers to test
cDNA libraries or applying RT-PCR, exon trapping/amplification, or other
techniques. This process frequently amounts to 'guessing' PCR primers on
top of unreliable gene predictions and frequently leads to wasting of
experimental efforts. RESULTS: The present paper proposes a simple and
reliable algorithm for experimental gene identification which bypasses the
unreliable gene prediction step. Studies of the performance of the
algorithm on a sample of human genes indicate that an experimental protocol
based on the algorithm's predictions achieves an accurate gene
identification with relatively few PCR primers. Predictions of PCR primers
may be used for exon amplification in preliminary mutation analysis during
an attempt to identify a gene responsible for a disease. We propose a
simple approach to find a short region from a genomic sequence that with
high probability overlaps with some exon of the gene. The algorithm is
enhanced to find one or more segments that are probably contained in the
translated region of the gene and can be used as PCR primers to select
appropriate clones in cDNA libraries by selective amplification. The
algorithm is further extended to locate a set of PCR primers that uniformly
cover all translated regions and can be used for RT-PCR and further
sequencing of (unknown) mRNA.
相似文献