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911.
Ehrlich carcinoma and EL-4 thymoma ascites cells were subjected in vitro to heat shock, ATP depletion, oxidative stress, Ca2+ overlading and iodoacetamide treatment. After the transient stresses, Triton (X-100)-insoluble TIS) fractions were isolated from the cells and analysed by electrophoresis and immunoblotting. All stresses used caused rapid aggregation of cell proteins. This was manifested in a signficant rise in protein content in the TIS fractions. The protein increase was mostly due to and increase in the insolubility of actin, 57 kDa protein of intermediate filaments, 70 kDa heat shock protein (HSP 70), and some specific proteins whose insolubilization was a characteristic sign for each type of cell injury. Different survival rates in the cell lines after either stress corrlated well with differences in their TIS protein accretion. Possible mechanisms for stress-induced protein aggregation and its relationship with cell viability are suggested. 相似文献
912.
R. J. Capon K. Elsbury M. S. Butler C. C. Lu J. N. A. Hooper J. A. P. Rostas K. J. O'Brien L. -M. Mudge A. T. R. Sim 《Cellular and molecular life sciences : CMLS》1993,49(3):263-264
The Antarctic marine spongeTedania charcoti has been shown to contain extraordinarily high natural concentrations of cadmium and zinc, which have in turn been correlated to the ability of the crude ethanol extract to modulate protein phosphorylation in chicken forebrain and to inhibit the growth of several test bacteria. 相似文献
913.
In order to improve the quality of yarn,a research was carried out at ring spinning.A modifiedtraveller has been used to reduce the yarn hairiness vastly.According to the statistical analysis ofthe data,it was found that the geometrical shape of travellers is the key factor affecting the yarnhairiness at ring spinning. 相似文献
914.
The differences of thermal conduction and its temperature-varying track of the heat source body at various structural environments have been studied. Hypothetically , geologic heat source body is cut successively into several segregative bodies with a fixed cubage . With the segmented number increasing , the conductive surface area of heat source body begins to get larger, which separately is similar to the heat geologic body in different tectonic zones that
has a various enclosed coefficient . Finite-element simulation result shows that
the thermal conduction speed of spreading from the heat source body to its wall rock is slow→higher→ highest, when heat source bodies are situated respectively at compressive, shear and tensile deformation zones, corresponding rates of their temperature drop are low→ higher→ highest .
Research indicates that the temperature ' s dropping rate of heat source body has an inverse relationship with enclosed coefficient η for different structural zones . This result can explain the tectono-physicochemical reason of magmatite evolution and its. difference . 相似文献
915.
A plant regulator controlling development of symbiotic root nodules 总被引:37,自引:0,他引:37
916.
917.
918.
919.
Sequence and analysis of chromosome 2 of the plant Arabidopsis thaliana 总被引:21,自引:0,他引:21
Lin X Kaul S Rounsley S Shea TP Benito MI Town CD Fujii CY Mason T Bowman CL Barnstead M Feldblyum TV Buell CR Ketchum KA Lee J Ronning CM Koo HL Moffat KS Cronin LA Shen M Pai G Van Aken S Umayam L Tallon LJ Gill JE Adams MD Carrera AJ Creasy TH Goodman HM Somerville CR Copenhaver GP Preuss D Nierman WC White O Eisen JA Salzberg SL Fraser CM Venter JC 《Nature》1999,402(6763):761-768
Arabidopsis thaliana (Arabidopsis) is unique among plant model organisms in having a small genome (130-140 Mb), excellent physical and genetic maps, and little repetitive DNA. Here we report the sequence of chromosome 2 from the Columbia ecotype in two gap-free assemblies (contigs) of 3.6 and 16 megabases (Mb). The latter represents the longest published stretch of uninterrupted DNA sequence assembled from any organism to date. Chromosome 2 represents 15% of the genome and encodes 4,037 genes, 49% of which have no predicted function. Roughly 250 tandem gene duplications were found in addition to large-scale duplications of about 0.5 and 4.5 Mb between chromosomes 2 and 1 and between chromosomes 2 and 4, respectively. Sequencing of nearly 2 Mb within the genetically defined centromere revealed a low density of recognizable genes, and a high density and diverse range of vestigial and presumably inactive mobile elements. More unexpected is what appears to be a recent insertion of a continuous stretch of 75% of the mitochondrial genome into chromosome 2. 相似文献
920.
A structural change in the kinesin motor protein that drives motility 总被引:34,自引:0,他引:34
Rice S Lin AW Safer D Hart CL Naber N Carragher BO Cain SM Pechatnikova E Wilson-Kubalek EM Whittaker M Pate E Cooke R Taylor EW Milligan RA Vale RD 《Nature》1999,402(6763):778-784
Kinesin motors power many motile processes by converting ATP energy into unidirectional motion along microtubules. The force-generating and enzymatic properties of conventional kinesin have been extensively studied; however, the structural basis of movement is unknown. Here we have detected and visualized a large conformational change of an approximately 15-amino-acid region (the neck linker) in kinesin using electron paramagnetic resonance, fluorescence resonance energy transfer, pre-steady state kinetics and cryo-electron microscopy. This region becomes immobilized and extended towards the microtubule 'plus' end when kinesin binds microtubules and ATP, and reverts to a more mobile conformation when gamma-phosphate is released after nucleotide hydrolysis. This conformational change explains both the direction of kinesin motion and processive movement by the kinesin dimer. 相似文献