Directional Asymmetry
Mostrando 13-19 de 19 artigos, teses e dissertações.
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13. Asymmetric Sequence Divergence of Duplicate Genes
Much like humans, gene duplicates may be created equal, but they do not stay that way for long. For four completely sequenced genomes we show that 20%–30% of duplicate gene pairs show asymmetric evolution in the amino acid sequence of their protein products. That is, one of the duplicates evolves much faster than the other. The greater this asymmetry,
Cold Spring Harbor Laboratory Press.
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14. Lack of cleavage of IcsA in Shigella flexneri causes aberrant movement and allows demonstration of a cross-reactive eukaryotic protein.
Once in the cytoplasm of mammalian cells, Shigella flexneri expresses a motile phenotype caused by polar directional assembly of actin. This process depends on accumulation of IcsA (VirG), a 120-kDa protein with ATPase activity, at the pole of the bacterium opposite to that at which ongoing septation occurs. IcsA is also secreted into the bacterial supernata
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15. Visualization of the movement of single histidine kinase molecules in live Caulobacter cells
The bacterium Caulobacter crescentus divides asymmetrically as part of its normal life cycle. This asymmetry is regulated in part by the membrane-bound histidine kinase PleC, which localizes to one pole of the cell at specific times in the cell cycle. Here, we track single copies of PleC labeled with enhanced yellow fluorescent protein (EYFP) in the membrane
National Academy of Sciences.
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16. Motility of ActA protein-coated microspheres driven by actin polymerization
Actin polymerization is required for the generation of motile force at the leading edge of both lamellipodia and filopodia and also at the surface of motile intracellular bacterial pathogens such as Listeria monocytogenes. Local catalysis of actin filament polymerization is accomplished in L. monocytogenes by the bacterial protein ActA. Polystyrene beads coa
The National Academy of Sciences.
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17. Binocular co-ordination of human horizontal saccadic eye movements.
1. The binocular co-ordination of human horizontal saccades was analysed for the first time systematically over the full oculomotor range with a precise and accurate scleral sensor coil technique. Effects of amplitude (1.25-80 deg), direction (adduction vs. abduction and centrifugal vs. centripetal) and eccentricity (symmetrical about primary or between prim
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18. Selective stabilization of microtubules oriented toward the direction of cell migration.
A small subset of the microtubule (MT) array in many cultured cells does not exhibit the rapid turnover (t 1/2 approximately equal to 10 min) shown by most cellular MTs. The function of the stable class of MTs is unknown and has been confounded by the apparent lack of organization of stable MTs within cells. Using an antibody against detyrosinated tubulin, a
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19. Dynamic Positioning of Mitotic Spindles in Yeast:: Role of Microtubule Motors and Cortical DeterminantsV⃞
In the budding yeast Saccharomyces cerevisiae, movement of the mitotic spindle to a predetermined cleavage plane at the bud neck is essential for partitioning chromosomes into the mother and daughter cells. Astral microtubule dynamics are critical to the mechanism that ensures nuclear migration to the bud neck. The nucleus moves in the opposite directio
The American Society for Cell Biology.