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111.
This study provides evidence that treatment with preclustered ephrin A5-Fc results in a substantial increase in the stability of the p110γ PI-3 kinase associated with EphA8, thereby enhancing PI-3 kinase activity and cell migration on a fibronectin substrate. In contrast, co-expression of a lipid kinase-inactive p110γ mutant together with EphA8 inhibits ligand-stimulated PI-3 kinase activity and cell migration on a fibronectin substrate, suggesting that the mutant has a dominant negative effect against the endogenous p110γ PI-3 kinase. Significantly, the tyrosine kinase activity of EphA8 is not important for either of these processes. Taken together, our results demonstrate that the stimulation of cell migration on a fibronectin substrate by the EphA8 receptor depends on the p110γ PI-3 kinase but is independent of a tyrosine kinase activity. 相似文献
112.
Hot pepper (Capsicum annuum) plants exhibit a hypersensitive response (HR) against infection by many tobamoviruses. A clone (CaPR-4) encoding a putative pathogenesis-related protein 4 was isolated by differential screening of a cDNA library prepared from resistant pepper plant leaves inoculated with tobacco mosaic virus (TMV) pathotype P0. The predicted amino acid sequence of CaPR-4 is very similar to those of other plant PR-4s. Southern blot analysis showed that small gene families of PR-4-related sequences were present in the pepper genome. Hot pepper cultivar Bugang, resistant to TMV-P0 and susceptible to TMV-P1.2, induced CaPR-4 expression by pathotype P0 inoculation in inoculated and systemic leaves, but not by pathotype P1.2. Effects of exogenously applied abiotic elicitors upon the CaPR-4 expression were also examined. The expression of the CaPR-4 gene was stimulated by methyl jasmonate (MeJA), ethephon and wounding treatment. However, application of salicylic acid (SA) did not trigger the expression. Evidence is emerging that jasmonic acid and ethylene play key roles in the SA-independent pathways of plant-pathogen interaction. Taken together, these results suggest that the CaPR-4 gene is one of the defense-related genes conferring resistance on pepper plants by the SA-independent pathway and the cross-talk between signaling compounds, jasmonic acid and ethylene could have a great regulatory potential in a plant's defense against TMV. 相似文献
113.
Ki-Woong Han Jinsang Yoo Eun-Joo Oh Jeong Jin Choi Hyun-Kyu Kim Suk-Tae Kwon 《Biotechnology letters》2001,23(5):379-384
The gene (bglT) encoding Thermus caldophilus GK24 -glycosidase (Tca -glycosidase) was cloned and sequenced. The gene contains an open reading frame encoding 431 amino acids with a M
r of 48 658 Da. The bglT gene was expressed under the control of tac promoter on a high-copy plasmid in E. coli. The recombinant Tca -glycosidase was purified 41.5-fold with a 59% yield and a specific activity of 83 U mg–1 protein. 相似文献
114.
Wang X Kaetzel MA Yoo SE Kim PS Dedman JR 《American journal of physiology. Cell physiology》2002,282(6):C1313-C1321
The exposure of anionic phospholipidson the external surface of injured endothelial cells and activatedplatelets is a primary biological signal to initiate blood coagulation.Disease conditions that promote the formation of ectopic thrombi resultin tissue ischemia. Annexins, Ca2+-dependentanionic phospholipid binding proteins, are potential therapeutic agentsfor the inhibition of coagulation. We have designed a transgene thattargets secretion of annexin V from cultured thyroid cells under thecontrol of doxycycline. Our results indicate that annexin V in theendoplasmic reticulum (ER)/Golgi lumen does not affect the synthesis,processing, and secretion of thyroglobulin. ER luminal Ca2+was moderately increased and can be released by inositol1,4,5-trisphosphate. Our study demonstrates that targeting andsecretion of annexin V through the secretory pathway of mammalian cellsdoes not adversely affect cellular function. Regulated synthesis andrelease of annexin V may exert anticoagulatory and anti-inflammatoryeffects systemically and may prove useful in further developingtherapeutic strategies for conditions including antiphospholipid syndrome. 相似文献
115.
116.
Artemisia annua hairy roots were grown in liquid-phase bubble column and gas-phase nutrient mist reactors. In most cases the bubble column reactor accumulated more biomass than the mist reactor; the highest final biomass concentrations observed were 15.3 g DW/L in the bubble column reactor and 14.4 g DW/L in the mist reactor. Further analysis showed that the average specific growth rate in the mist reactors was essentially constant and independent of the biomass concentration at the beginning of the mist mode. In contrast, at low packing densities the average growth rate in the bubble column reactors was higher than in the mist reactors, decreasing to comparable rates at high packing densities. Finally, an aerosol deposition model was used to compare the volume of medium captured by the root bed in the mist reactor to the volume of medium required to maintain a specified growth rate. The results suggest that under the current operating conditions, lower growth rates in the mist reactor may be due to insufficient nutrient availability. 相似文献
117.
Suppurative bronchopneumonia was discovered in a 6-yr-old male jaguar (Panthera onca onca) that died after a 1 wk history of anorexia, depression, and respiratory difficulty. Morganella morganii was isolated as a pure culture from the lung, spleen, and heart blood. This is the first record of M. morganii induced pneumonia in a jaguar. 相似文献
118.
119.
Wheatley W Yoo S Pierce M Rebentisch M Endo M Peterson I Stump M McCormack K Garcia-Guzman M Kamb A 《Biochemical genetics》2002,40(11-12):359-378
Transdominant genetic selections can yield protein fragment and peptide modulators of specific biochemical pathways. In yeast, such screens have been highly successful in targeting the MAP (mitogen-activated protein) kinase growth-control pathway. We performed a similar type of selection aimed at recovery of modulators of the mammalian MAP kinase cascade. Two pathway activators were identified, fragments of the TrkB and Raf-1 kinases. In a second selection directed at the beta-catenin growth-control pathway, three different clones encoding cadherin fragments were recovered. In neither selection were peptide inhibitors observed. We conclude that some transdominant selections in mammalian cells can readily yield high-penetrance protein fragments, but may be less amenable to isolation of peptide inhibitors. 相似文献
120.
Generation of histocompatible tissues using nuclear transplantation 总被引:27,自引:0,他引:27