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排序方式: 共有930条查询结果,搜索用时 140 毫秒
71.
Hannah M��ller David Schmidt Sandra Steinbrink Ekaterina Mirgorodskaya Verena Lehmann Karin Habermann Felix Dreher Niklas Gustavsson Thomas Kessler Hans Lehrach Ralf Herwig Johan Gobom Aspasia Ploubidou Michael Boutros Bodo M H Lange 《The EMBO journal》2010,29(19):3344-3357
Regulation of centrosome structure, duplication and segregation is integrated into cellular pathways that control cell cycle progression and growth. As part of these pathways, numerous proteins with well‐established non‐centrosomal localization and function associate with the centrosome to fulfill regulatory functions. In turn, classical centrosomal components take up functional and structural roles as part of other cellular organelles and compartments. Thus, although a comprehensive inventory of centrosome components is missing, emerging evidence indicates that its molecular composition reflects the complexity of its functions. We analysed the Drosophila embryonic centrosomal proteome using immunoisolation in combination with mass spectrometry. The 251 identified components were functionally characterized by RNA interference. Among those, a core group of 11 proteins was critical for centrosome structure maintenance. Depletion of any of these proteins in Drosophila SL2 cells resulted in centrosome disintegration, revealing a molecular dependency of centrosome structure on components of the protein translation machinery, actin‐ and RNA‐binding proteins. In total, we assigned novel centrosome‐related functions to 24 proteins and confirmed 13 of these in human cells. 相似文献
72.
Adhesion and migration are integrated cell functions that build, maintain and remodel the multicellular organism. In migrating
cells, integrins are the main transmembrane receptors that provide dynamic interactions between extracellular ligands and
actin cytoskeleton and signalling machineries. In parallel to integrins, other adhesion systems mediate adhesion and cytoskeletal
coupling to the extracellular matrix (ECM). These include multifunctional cell surface receptors (syndecans and CD44) and
discoidin domain receptors, which together coordinate ligand binding with direct or indirect cytoskeletal coupling and intracellular
signalling. We review the way that the different adhesion systems for ECM components impact cell migration in two- and three-dimensional
migration models. We further discuss the hierarchy of these concurrent adhesion systems, their specific tasks in cell migration
and their contribution to migration in three-dimensional multi-ligand tissue environments. 相似文献
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75.
In order to test if DQB is a good candidate marker to investigate the relationship between major histocompatibility complex
genes and pathogens in natural populations of Mastomys natalensis, we assessed the polymorphism and evolutionary history of this gene. Twenty-four individuals were genotyped for exon 2 of
DQB using capillary electrophoresis single-strand conformation polymorphism, cloning, and sequencing. We found 21 different
alleles. Four individuals show three alleles implying a duplication event in the history of this gene. Each distinct sequence
translates to give a distinct amino acid sequence and there are strong signals of positive selection on peptide binding sites.
Signals of recombination were found in the sequences suggesting that recombination has played a role in generating allelic
diversity. Although trans-taxon polymorphism is present at the interspecific level in DQB exon 2 sequences of Mus species, we did not find any evidence of allele sharing among Muridae genera. This indicates a temporal limit of DQB allele
sharing in Muridae of less than 8 Mya. In conclusion, although DQB seems to be a good marker to investigate pathogen-driven
selection, the polymorphism of gene copy number may restrict its utility in natural populations. 相似文献
76.
The visual pathway is tasked with processing incoming signals from the retina and converting this information into adaptive
behavior. Recent studies of the larval zebrafish tectum have begun to clarify how the 'micro-circuitry' of this highly organized
midbrain structure filters visual input, which arrives in the superficial layers and directs motor output through efferent
projections from its deep layers. The new emphasis has been on the specific function of neuronal cell types, which can now
be reproducibly labeled, imaged and manipulated using genetic and optical techniques. Here, we discuss recent advances and
emerging experimental approaches for studying tectal circuits as models for visual processing and sensorimotor transformation
by the vertebrate brain. 相似文献
77.
78.
Sultan M Piccini I Balzereit D Herwig R Saran NG Lehrach H Reeves RH Yaspo ML 《Genome biology》2007,8(5):R91
Background
Down's syndrome (DS), or trisomy 21, is a complex developmental disorder that exhibits many clinical signs that vary in occurrence and severity among patients. The molecular mechanisms responsible for DS have thus far remained elusive. We argue here that normal variation in gene expression in the population contributes to the heterogeneous clinical picture of DS, and we estimated the amplitude of this variation in 50 mouse orthologs of chromosome 21 genes in brain regions of Ts65Dn (a mouse model of DS). We analyzed the RNAs of eight Ts65Dn and eight euploid mice by real-time polymerase chain reaction. 相似文献79.
80.