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Dynamic Organization (dynamic + organization)
Selected AbstractsDynamic organization of lymphocyte plasma membrane: lessons from advanced imaging methodsIMMUNOLOGY, Issue 1 2010Dylan M. Owen Summary Lipids and lipid domains are suggested to play an essential role in the heterogeneous organization of the plasma membrane in eukaryotic cells, including cells of the immune system. We summarize the results of advanced imaging and physical studies of membrane organization with special focus on the plasma membrane of lymphocytes. We provide a comprehensive up-to-date view on the existence of membrane lipid and protein clusters such as lipid rafts and suggest research directions to better understand these highly dynamic entities on the surface of immune cells. [source] Dynamic organization of COPII coat proteins at endoplasmic reticulum export sites in plant cellsTHE PLANT JOURNAL, Issue 6 2009Sally L. Hanton Summary Protein export from the endoplasmic reticulum (ER) is mediated by the accumulation of COPII proteins such as Sar1, Sec23/24 and Sec13/31 at specialized ER export sites (ERES). Although the distribution of COPII components in mammalian and yeast systems is established, a unified model of ERES dynamics has yet to be presented in plants. To investigate this, we have followed the dynamics of fluorescent fusions to inner and outer components of the coat, AtSec24 and AtSec13, in three different plant model systems: tobacco and Arabidopsis leaf epidermis, as well as tobacco BY-2 suspension cells. In leaves, AtSec24 accumulated at Golgi-associated ERES, whereas AtSec13 showed higher levels of cytosolic staining compared with AtSec24. However, in BY-2 cells, both AtSec13 and AtSec24 labelled Golgi-associated ERES, along with AtSec24. To correlate the distribution of the COPII coat with the dynamics of organelle movement, quantitative live-cell imaging analyses demonstrated that AtSec24 and AtSec13 maintained a constant association with Golgi-associated ERES, irrespective of their velocity. However, recruitment of AtSec24 and AtSec13 to ERES, as well as the number of ERES marked by these proteins, was influenced by export of membrane cargo proteins from the ER to the Golgi. Additionally, the increased availability of AtSec24 affected the distribution of AtSec13, inducing recruitment of this outer COPII coat component to ERES. These results provide a model that, in plants, protein export from the ER occurs via sequential recruitment of inner and outer COPII components to form transport intermediates at mobile, Golgi-associated ERES. [source] Proteome analysis of human nuclear insoluble fractionsGENES TO CELLS, Issue 8 2009Hideaki Takata The interphase nucleus is a highly ordered and compartmentalized organelle. Little is known regarding what elaborate mechanisms might exist to explain these properties of the nucleus. Also unresolved is whether some architectural components might facilitate the formation of functional intranuclear compartments or higher order chromatin structure. As the first step to address these questions, we performed an in-depth proteome analysis of nuclear insoluble fractions of human HeLa-S3 cells prepared by two different approaches: a high-salt/detergent/nuclease-resistant fraction and a lithium 3,5-diiodosalicylate/nuclease-resistant fraction. Proteins of the fractions were analyzed by liquid chromatography electrospray ionization tandem mass spectrometry, identifying 333 and 330 proteins from each fraction respectively. Among the insoluble nuclear proteins, we identified 37 hitherto unknown or functionally uncharacterized proteins. The RNA recognition motif, WD40 repeats, HEAT repeats and the SAP domain were often found in these identified proteins. The subcellular distribution of selected proteins, including DEK protein and SON protein, demonstrated their novel associations with nuclear insoluble materials, corroborating our MS-based analysis. This study establishes a comprehensive catalog of the nuclear insoluble proteins in human cells. Further functional analysis of the proteins identified in our study will significantly improve our understanding of the dynamic organization of the interphase nucleus. [source] Dynamic and Reversible Organization of Zeolite L Crystals Induced by Holographic Optical TweezersADVANCED MATERIALS, Issue 37 2010Mike Woerdemann Organization and patterning of zeolite L crystals with their unique properties such as their one-dimensional nano channel system is of highest topical interest with various applications in many areas of science. We demonstrate full three-dimensional optical control of single zeolite L crystals and for the first time fully reversible, dynamic organization of a multitude of individually controlled zeolite L crystals. [source] Differential expression of p120 catenin in glial cells of the adult rat brainTHE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 1 2004Norbert Chauvet Abstract p120 catenin (p120ctn) is involved in the regulation of cadherin-mediated adhesion and the dynamic organization of the actin cytoskeleton by modulating RhoGTPase activity. We have previously described the distribution of p120ctn during rat brain development and provided substantial evidence for the potential involvement of p120ctn in morphogenetic events and plasticity in the central nervous system. Here, we analyzed the cellular and ultrastructural distribution of p120ctn in glial cells of the adult rat forebrain. The highest intensity of immunostaining for p120ctn was found in cells of the choroid plexus and ependyma and was mainly restricted to the plasma membrane. However, p120ctn was almost absent from astrocytes. In contrast, in tanycytes, a particular glial cell exhibiting remarkable morphological plasticity, p120ctn, was localized at the plasma membrane and also in the cytoplasm. We show that a large subpopulation of oligodendrocytes expressed multiple isoforms, whereas other neural cells predominantly expressed isoform 1, and that p120ctn immunoreactivity was distributed through the cytoplasm and at certain portions of the plasma membrane. Finally, p120ctn was expressed by a small population of cortical NG2-expressing cells, whereas it was expressed by a large population of these cells in the white matter. However, in both regions, proliferating NG2-positive cells consistently expressed p120ctn. The expression of p120ctn by cells of the oligodendrocyte lineage suggests that p120ctn may participate in oligodendrogenesis and myelination. Moreover, the expression of p120ctn by various cell types and its differential subcellular distribution strongly suggest that p120ctn may serve multiple functions in the central nervous system. J. Comp. Neurol. 479:15,29, 2004. © 2004 Wiley-Liss, Inc. [source] Islam in Northern Mozambique: A Historical OverviewHISTORY COMPASS (ELECTRONIC), Issue 7 2010Liazzat Bonate This article is a historical overview of two issues: first, that of the dynamics of Islamic religious transformations from pre-Portuguese era up until the 2000s among Muslims of the contemporary Cabo Delgado, Nampula, and to a certain extent, Niassa provinces. The article argues that historical and geographical proximity of these regions to East African coast, the Comoros and northern Madagascar meant that all these regions shared a common Islamic religious tradition. Accordingly, shifts with regard to religious discourses and practices went in parallel. This situation began changing in the last decade of the colonial era and has continued well into the 2000s, when the so-called Wahhabis, Sunni Muslims educated in the Islamic universities of the Arab world brought religious outlook that differed significantly from the historical local and regional conceptions of Islam. The second question addressed in this article is about relationships between northern Mozambican Muslims and the state. The article argues that after initial confrontations with Muslims in the sixteenth century and up until the last decade of the colonial era, the Portuguese rule pursued no concerted effort in interfering in the internal Muslim religious affairs. Besides, although they occupied and destroyed some of the Swahili settlements, in particular in southern and central Mozambique, other Swahili continued to thrive in northern Mozambique and maintained certain independence from the Portuguese up until the twentieth century. Islam there remained under the control of the ruling Shirazi clans with close political, economic, kinship and religious ties to the Swahili world. By establishing kinship and politico-economic ties with the ruling elites of the mainland in the nineteenth century, these families were also instrumental in expanding Islam into the hinterland. Only at the beginning of the twentieth century, the Portuguese rule took full control of the region as a result of military conquests of the ,effective occupation', and imposed new legal and administrative colonial system, called Indigenato, impacting Muslims of northern Mozambique to a great extent. After the independence in 1975, and especially since 1977, the post-independence Frelimo government adopted militant atheism and socialist Marxism, which was short-lived and was abolished in 1983 owing to popular resistance and especially, because of government's perception that its religious policies were fuelling the opposition groups to take arms and join the civil war. The 1980s and 1990s were marked by an acute rivalry and conflicts between the two emerging national umbrella Islamic organizations, the Islamic Council and the Islamic Congress, each representing largely pro-Sufi and anti-Sufi positions. In the 2000s, these organizations became overshadowed by new and more dynamic organizations, such as Ahl Al-Sunna. [source] | ||||||||||