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141.
142.
T. Matsui M. Matsuda O. Murayama B.C. Millar & J.E. Moore 《Letters in applied microbiology》2001,32(6):424-427
AIMS: To subtype Salmonella enteritidis phage type 4 isolates by using recA genotyping. METHODS AND RESULTS: Random amplified polymorphic DNA analysis using a primer ERIC2 of 76 isolates of Salmonella enteritidis phage type 4 obtained in Northern Ireland in 1998 and in 1999 demonstrated the presence of five genotypes. Restriction fragment length polymorphism analysis, using a degenerate primer pair designed to amplify a segment (about 640 bp in length) of the recA gene from several members of the Enterobacteriaceae with restriction enzymes, HhaI and Sau3AI, showed that the resulting fragments could differentiate the isolates into three groups, respectively. CONCLUSION: recA gene amplification and HhaI and Sau3AI restriction digestion was demonstrated to increase the differentiating power between isolates of Salmonella enteritidis phage type 4 by combining the patterns of the random amplified polymorphic DNA analysis procedure using a primer ERIC2. Significance and Impact of the Study: A novel restriction fragment length polymorphism assay for isolates of Salmonella enteritidis phage type 4, based on the amplification of the recA gene was attained and its comparison and its combination with random amplified polymorphic DNA analysis was provided. 相似文献
143.
Arabidopsis mitochondria are predicted to contain three acyl carrier proteins (ACPs). These small proteins are involved in fatty acid
and lipoic acid synthesis in other organisms and have been previously reported to be subunits of respiratory Complex I in
mitochondria in mammals, fungi and plants. Recently, the mammalian mitochondrial ACP (mtACP) has been shown to be largely
a soluble matrix protein but also to be minimally associated with Complex I (Cronan et al. 2005), consistent with its involvement in synthesis of lipoic acid for TCA cycle decarboxylating dehydrogenases in the matrix
but contrary to earlier claims it was primarily a Complex I subunit. We have investigated the localization of the ACPs in
Arabidopsis mitochondria. Evidence is presented that mtACP1 and mtACP2 dominate the ACP composition in Arabidopsis mitochondria, and both are present in the mitochondrial matrix rather than in the membrane. No significant amounts of mtACPs
were detected in Complex I isolated by blue native gel electrophoresis, rather mtACPs were detected at low molecular mass
in the soluble fraction, showing that in A. thaliana mtACPs are predominately free soluble matrix proteins. 相似文献
144.
Structural organization and a standardized nomenclature for plant endo-1,4-beta-glucanases (cellulases) of glycosyl hydrolase family 9
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145.
Salathia N Lynn JR Millar AJ King GJ 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2007,114(4):683-692
Circadian rhythms regulate many aspects of plant growth, fitness and vigour. The components and detailed mechanism of circadian
regulation to date have been dissected in the reference species Arabidopsis thaliana. To determine the genetic basis and range of natural allelic variation for intrinsic circadian period in the closest crop
relatives, we used an accurate and high throughput data capture system to record rhythmic cotyledon movement in two immortal
segregating populations of Brassica oleracea, derived from parent lines representing different crop types. Periods varied between 24.4 and 26.1 h between the parent lines,
with transgressive segregation between extreme recombinant lines in both populations of ∼3.5 h. The additive effect of individual
QTL identified in each population varied from 0.17 to 0.36 h. QTL detected in one doubled haploid population were verified
and the mapping intervals further resolved by determining circadian period in genomic substitution lines derived from the
parental lines. Comparative genomic analysis based on collinearity between Brassica and Arabidopsis also allowed identification of candidate orthologous genes known to regulate period in Arabidopsis, that may account for the additive circadian effects of specific QTL. The distinct QTL positions detected in the two populations,
and the extent of transgressive segregation suggest that there is likely to be considerable scope for modulating the range
of available circadian periods in natural populations and crop species of Brassica. This may provide adaptive advantage for optimising growth and development in different latitudes, seasons or climate conditions. 相似文献
146.
Leucine carboxyl methyltransferase-1 is necessary for normal progression through mitosis in mammalian cells 总被引:2,自引:0,他引:2
Protein phosphatase 2A (PP2A) is a multifunctional phosphatase that plays important roles in many cellular processes including regulation of cell cycle and apoptosis. Because PP2A is involved in so many diverse processes, it is highly regulated by both non-covalent and covalent mechanisms that are still being defined. In this study we have investigated the importance of leucine carboxyl methyltransferase-1 (LCMT-1) for PP2A methylation and cell function. We show that reduction of LCMT-1 protein levels by small hairpin RNAs causes up to a 70% reduction in PP2A methylation in HeLa cells, indicating that LCMT-1 is the major mammalian PP2A methyltransferase. In addition, LCMT-1 knockdown reduced the formation of PP2A heterotrimers containing the Balpha regulatory subunit and, in a subset of the cells, induced apoptosis, characterized by caspase activation, nuclear condensation/fragmentation, and membrane blebbing. Knockdown of the PP2A Balpha regulatory subunit induced a similar amount of apoptosis, suggesting that LCMT-1 induces apoptosis in part by disrupting the formation of PP2A(BalphaAC) heterotrimers. Treatment with a pan-caspase inhibitor partially rescued cells from apoptosis induced by LCMT-1 or Balpha knockdown. LCMT-1 knockdown cells and Balpha knockdown cells were more sensitive to the spindle-targeting drug nocodazole, suggesting that LCMT-1 and Balpha are important for spindle checkpoint. Treatment of LCMT-1 and Balpha knockdown cells with thymidine dramatically reduced cell death, presumably by blocking progression through mitosis. Consistent with these results, homozygous gene trap knock-out of LCMT-1 in mice resulted in embryonic lethality. Collectively, our results indicate that LCMT-1 is important for normal progression through mitosis and cell survival and is essential for embryonic development in mice. 相似文献
147.
148.
149.
150.
Smolock EM Wang T Nolt JK Moreland RS 《American journal of physiology. Cell physiology》2007,292(2):C876-C885
Contraction of smooth muscle involves myosin light chain (MLC) kinase catalyzed phosphorylation of the regulatory MLC, activation of myosin, and the development of force. However, this cannot account for all aspects of a smooth muscle contraction, suggesting that other regulatory mechanisms exist. One potentially important technique to study alternative sites of contractile regulation is the use of small interfering RNA (siRNA). The goal of this study was to determine whether siRNA technology can decrease the levels of a specific protein and allow for the determination of how that protein affects contractile regulation. To achieve this goal, we tested the hypothesis that casein kinase 2 (CK2) is part of the complex regulatory scheme present in vascular smooth muscle. Using intact strips of swine carotid artery, we determined that siRNA against CK2 produced a tissue that resulted in a 60% knockdown after 4 days in organ culture. Intact strips of vascular tissue depleted of CK2 produced greater levels of force and exhibited an increased sensitivity to all stimuli tested. This was accompanied by an increase in cross-bridge cycling rates but not by a change in MLC phosphorylation levels. -Toxin-permeabilized vascular tissue depleted of CK2 also showed an increased sensitivity to calcium compared with control tissues. Our results demonstrate that siRNA is a viable technique with which to study regulatory pathways in intact smooth muscle tissue. Our results also demonstrate that CK2 plays an important role in the mechanism(s) responsible for the development of force and cross-bridge cycling by a MLC phosphorylation-independent pathway. myosin light chain phosphorylation; shortening velocity; -toxin permeabilization; swine carotid artery; caldesmon 相似文献