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331.
Oaks JL Gilbert M Virani MZ Watson RT Meteyer CU Rideout BA Shivaprasad HL Ahmed S Chaudhry MJ Arshad M Mahmood S Ali A Khan AA 《Nature》2004,427(6975):630-633
332.
Ali K Bilancio A Thomas M Pearce W Gilfillan AM Tkaczyk C Kuehn N Gray A Giddings J Peskett E Fox R Bruce I Walker C Sawyer C Okkenhaug K Finan P Vanhaesebroeck B 《Nature》2004,431(7011):1007-1011
Inflammatory substances released by mast cells induce and maintain the allergic response. Mast cell differentiation and activation are regulated, respectively, by stem cell factor (SCF; also known as Kit ligand) and by allergen in complex with allergen-specific immunoglobulin E (IgE). Activated SCF receptors and high-affinity receptors for IgE (FcvarepsilonRI) engage phosphoinositide 3-kinases (PI(3)Ks) to generate intracellular lipid second messenger signals. Here, we report that genetic or pharmacological inactivation of the p110delta isoform of PI(3)K in mast cells leads to defective SCF-mediated in vitro proliferation, adhesion and migration, and to impaired allergen-IgE-induced degranulation and cytokine release. Inactivation of p110delta protects mice against anaphylactic allergic responses. These results identify p110delta as a new target for therapeutic intervention in allergy and mast-cell-related pathologies. 相似文献
333.
The male-specific region of the human Y chromosome is a mosaic of discrete sequence classes 总被引:2,自引:0,他引:2
Skaletsky H Kuroda-Kawaguchi T Minx PJ Cordum HS Hillier L Brown LG Repping S Pyntikova T Ali J Bieri T Chinwalla A Delehaunty A Delehaunty K Du H Fewell G Fulton L Fulton R Graves T Hou SF Latrielle P Leonard S Mardis E Maupin R McPherson J Miner T Nash W Nguyen C Ozersky P Pepin K Rock S Rohlfing T Scott K Schultz B Strong C Tin-Wollam A Yang SP Waterston RH Wilson RK Rozen S Page DC 《Nature》2003,423(6942):825-837
334.
Ubersax JA Woodbury EL Quang PN Paraz M Blethrow JD Shah K Shokat KM Morgan DO 《Nature》2003,425(6960):859-864
The events of cell reproduction are governed by oscillations in the activities of cyclin-dependent kinases (Cdks). Cdks control the cell cycle by catalysing the transfer of phosphate from ATP to specific protein substrates. Despite their importance in cell-cycle control, few Cdk substrates have been identified. Here, we screened a budding yeast proteomic library for proteins that are directly phosphorylated by Cdk1 in whole-cell extracts. We identified about 200 Cdk1 substrates, several of which are phosphorylated in vivo in a Cdk1-dependent manner. The identities of these substrates reveal that Cdk1 employs a global regulatory strategy involving phosphorylation of other regulatory molecules as well as phosphorylation of the molecular machines that drive cell-cycle events. Detailed analysis of these substrates is likely to yield important insights into cell-cycle regulation. 相似文献
335.
Genome divergence in two Prochlorococcus ecotypes reflects oceanic niche differentiation 总被引:1,自引:0,他引:1
Rocap G Larimer FW Lamerdin J Malfatti S Chain P Ahlgren NA Arellano A Coleman M Hauser L Hess WR Johnson ZI Land M Lindell D Post AF Regala W Shah M Shaw SL Steglich C Sullivan MB Ting CS Tolonen A Webb EA Zinser ER Chisholm SW 《Nature》2003,424(6952):1042-1047
The marine unicellular cyanobacterium Prochlorococcus is the smallest-known oxygen-evolving autotroph. It numerically dominates the phytoplankton in the tropical and subtropical oceans, and is responsible for a significant fraction of global photosynthesis. Here we compare the genomes of two Prochlorococcus strains that span the largest evolutionary distance within the Prochlorococcus lineage and that have different minimum, maximum and optimal light intensities for growth. The high-light-adapted ecotype has the smallest genome (1,657,990 base pairs, 1,716 genes) of any known oxygenic phototroph, whereas the genome of its low-light-adapted counterpart is significantly larger, at 2,410,873 base pairs (2,275 genes). The comparative architectures of these two strains reveal dynamic genomes that are constantly changing in response to myriad selection pressures. Although the two strains have 1,350 genes in common, a significant number are not shared, and these have been differentially retained from the common ancestor, or acquired through duplication or lateral transfer. Some of these genes have obvious roles in determining the relative fitness of the ecotypes in response to key environmental variables, and hence in regulating their distribution and abundance in the oceans. 相似文献
336.
337.
The gastrocnemius muscle of the rat showed no morphological, histometric or plasma membrane changes, after sciatic nerve stimulation with a 5mA current for 30 to 60 min, 10 mA for 30 min and 15 mA for 5 min. However, 10 mA for 60 and 200 min gave rise to mitochondrial and plasma membrane abnormalities. These changes were absent after a rest period. The results indicated that the sciatic nerve stimulation at 10 mA for 60 and 200 min caused reversible changes in the rat skeletal muscle mitochondria and plasma membrane. 相似文献
338.
Résumé Les Fréquences de Fusion de l'Electrorétinogramme (FFF) ont été enregistrées chez les truites mouchetées (Salvelinus fontinalis) normales et albinos. Chez les poissons adaptés à la lumière ainsi qu'à l'obscurité les valeurs sont plus élevées chez les albinos que chez les animaux normaux. Les valeurs maximum de FFF sont aussi atteintes à des intensités moins élevées chez les albinos. Ces différences sont attribuables à l'entrée d'une plus grande quantité de lumière ainsi qu'à sa réflection par la sclérotique, ce qui est due au manque de pigment épithelial rétinien. 相似文献
339.
S. S. Ranade Smita Shah Pallavi Haria 《Cellular and molecular life sciences : CMLS》1979,35(4):460-461
Summary In this report we present an analysis by atomic absorption spectrometry of some of the transition metals Fe, Zn, Cu, Mn, Co, and Ni in tissues and nuclear fractions in an experimental tumour system.Acknowledgments. The atomic absorption spectroscopic analysis was done at the Health Physics Division, Bhabha Atomic Research Centre, Bombay. The author are indebted to Dr S.D. Soman, Director, Health Physics Division for providing facilities for the said analysis. 相似文献
340.
The alterations in ornithine decarboxylase activity in response to in vitro treatment with bromocriptine suggest the possible direct action of the drug on gonads. 相似文献