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41.
Construction of a 'unigene' cDNA clone set by oligonucleotide fingerprinting allows access to 25 000 potential sugar beet genes 总被引:1,自引:0,他引:1
42.
Elsasser S Gali RR Schwickart M Larsen CN Leggett DS Müller B Feng MT Tübing F Dittmar GA Finley D 《Nature cell biology》2002,4(9):725-730
The yeast protein Rad23 belongs to a diverse family of proteins that contain an amino-terminal ubiquitin-like (UBL) domain. This domain mediates the binding of Rad23 to proteasomes, which in turn promotes DNA repair and modulates protein degradation, possibly by delivering ubiquitinylated cargo to proteasomes. Here we show that Rad23 binds proteasomes by directly interacting with the base subcomplex of the regulatory particle of the proteasome. A component of the base, Rpn1, specifically recognizes the UBL domain of Rad23 through its leucine-rich-repeat-like (LRR-like) domain. A second UBL protein, Dsk2, competes with Rad23 for proteasome binding, which suggests that the LRR-like domain of Rpn1 may participate in the recognition of several ligands of the proteasome. We propose that the LRR domain of Rpn1 may be positioned in the base to allow the cargo proteins carried by Rad23 to be presented to the proteasomal ATPases for unfolding. We also report that, contrary to expectation, the base subunit Rpn10 does not mediate the binding of UBL proteins to the proteasome in yeast, although it can apparently contribute to the binding of ubiquitin chains by intact proteasomes. 相似文献
43.
We examined the seed rain throughout a twelve month period in a lowlandtropical forest in Cameroon, West Africa, 1996–97. Traps (0.5m2, n = 216) were erected throughout a 25km2 area in 24 randomly placed clusters of nine trapseach. Fruits and seeds that landed in traps were collected every 7–10daysand classified by species and dispersal type. More than 32,000 seeds fromapproximately 200 species fell into the traps, an average of 297 seedsm–2 yr–1 Thirty species represent 82%of the total seed rain while an additional 175 species comprise the remaining18%. When we compared the adult community to the seed rain community within thesame plots, we found no apparent correlation between seed rain patterns andadult community structure for this year of study. Furthermore, only 49% of theadult tree community produced and dispersed seed into traps in this year. Morethan 100 species (52%) found in the seed rain represented long-distanceimmigrant seed rain. Seed rain was highly variable at several scales, bothspatially and seasonally, although seeds arrived in traps during eachcollectionperiod. Cluster analyses showed that traps within plots were seldom moresimilarto one another than traps between plots. While 82% of the tree species in thecommunity are thought to be animal dispersed, only 28% of all seeds that fellinto traps had been obviously handled (bitten, chewed, or passed)by animals. Tests for fruit and seed removal by predators or dispersers found5%or less removal rate from traps. 相似文献
44.
45.
Road map to metastasis 总被引:9,自引:0,他引:9
46.
Formation and nuclear export of tRNA, rRNA and mRNA is regulated by the ubiquitin ligase Rsp5p 总被引:3,自引:0,他引:3
Neumann S Petfalski E Brügger B Grosshans H Wieland F Tollervey D Hurt E 《EMBO reports》2003,4(12):1156-1162
47.
Lau IF Filipe SR Søballe B Økstad OA Barre FX Sherratt DJ 《Molecular microbiology》2003,49(3):731-743
The positions of DNA regions close to the chromosome replication origin and terminus in growing cells of Escherichia coli have been visualized simultaneously, using new widely applicable reagents. Furthermore, the positions of these regions with respect to a replication factory-associated protein have been analysed. Time-lapse analysis has allowed the fate of origins, termini and the FtsZ ring to be followed in a lineage-specific manner during the formation of microcolonies. These experiments reveal new aspects of the E. coli cell cycle and demonstrate that the replication terminus region is frequently located asymmetrically, on the new pole side of mid-cell. This asymmetry could provide a mechanism by which the chromosome segregation protein FtsK, located at the division septum, can act directionally to ensure that the septal region is free of DNA before the completion of cell division. 相似文献
48.
Effect of Serine and Ethanolamine Administration on Phospholipid-Related Compounds and Neurotransmitter Amino Acids in the Rabbit Hippocampus 总被引:1,自引:1,他引:0
Sandra Buratta Anders Hamberger Henrik Ryberg Britta Nyström Mats Sandberg Rita Mozzi 《Journal of neurochemistry》1998,71(5):2145-2150
Abstract: The report concerns mechanisms for the increase of extracellular levels of ethanolamine and phosphoethanolamine in CNS regions, such as the hippocampus, in transient brain ischemia, hypoglycemia, seizures, etc. l -Serine (2.5–10 m M ), d -serine (10 m M ), or ethanolamine (10 m M ) was administered for 20 min via a microdialysis tubing to the hippocampus of unanesthetized rabbits. The concentrations of primary amines were determined in the dialysates. When levels were elevated 10–100 times in the extracellular fluid, l -serine caused a dose-dependent increase of the concentration of extracellular ethanolamine. Ethanolamine caused a corresponding, although somewhat smaller, increase in serine levels. Furthermore, l -serine also induced an increased concentration of phosphoethanolamine that was delayed in time relative to the peak of ethanolamine. d -Serine was as effective as l -serine in raising ethanolamine levels but had no effect on phosphoethanolamine. Ethanolamine, but not l -serine, also increased extracellular glutamate/aspartate levels in an MK-801-dependent fashion. A similar effect, but delayed in time, was observed with d -serine. These effects were inhibited by MK-801. The concentrations of other amino acids were not significantly affected. The characteristics of the effects are suggestive of base exchange reactions between serine and ethanolamine and between ethanolamine and serine glycerophospholipids, respectively, in neuronal plasma membranes. 相似文献
49.
Bernd Wissinger Herbert Jägle Susanne Kohl Martina Broghammer Britta Baumann David B Hanna Christian Hedels Eckhard Apfelstedt-Sylla Giorgio Randazzo Samuel G Jacobson Eberhart Zrenner Lindsay T Sharpe 《Genomics》1998,51(3):325
We have performed linkage analysis in eight families with rod monochromacy, an autosomal recessively inherited condition with complete color blindness. Significant linkage was found with markers located at the pericentromeric region of chromosome 2. A maximum lod score of 5.36 was obtained for marker D2S2333 at θ = 0.00. Mapping of meiotic breakpoints localized the disease gene between markers D2S2187 and D2S2229. Homozygosity for a number of subsequent markers indicating identity by descent was found in two families and provides evidence for a further refinement of the locus proximal to D2S373. This defines an interval of ≈3 cM covering theACHM2locus for rod monochromacy. Radiation hybrid mapping of theCNGA3gene encoding the α-subunit of the cGMP gated cation channel in human cone photoreceptors resulted in a maximum lod score of 16.1 with marker D2S2311 combined with a calculated physical distance of 6.19cR10,000. Screening of the CEPH YAC library and subsequent STS mapping indicated the physical order cen–D2S2222–D2S2175–(D2S2187/D2S2311)–qtel ofmarkers on 2q11 and showed that theCNGA3gene maps most closely to D2S2187 and D2S2311. These data indicate that theCNGA3gene maps within the critical interval of theACHM2locus for rod monochromacy and thus is a candidate gene for this disease. 相似文献
50.
Türkân Saknç Britta Kleine Nadine Michalski Martin Kaase & Sören G. Gatermann 《FEMS microbiology letters》2009,301(1):28-34
The transferability of a large plasmid that harbors a tetracycline resistance gene tet (S), to fish and human pathogens was assessed using electrotransformation and conjugation. The plasmid, originally isolated from fish intestinal Lactococcus lactis ssp. lactis KYA-7, has potent antagonistic activity against the selected recipients ( Lactococcus garvieae and Listeria monocytogenes ), preventing conjugation. Therefore the tetracycline resistance determinant was transferred via electroporation to L . garvieae . A transformant clone was used as the donor in conjugation experiments with three different L. monocytogenes strains. To our knowledge, this is the first study showing the transfer of an antibiotic resistance plasmid from fish-associated lactic bacteria to L. monocytogenes , even if the donor L. garvieae was not the original host of the tetracycline resistance but experimentally created by electroporation. These results demonstrate that the antibiotic resistance genes in the fish intestinal bacteria have the potential to spread both to fish and human pathogens, posing a risk to aquaculture and consumer safety. 相似文献