Search results for " Amin"
showing 10 items of 944 documents
The Fibril-associated Collagen IX Provides a Novel Mechanism for Cell Adhesion to Cartilaginous Matrix
2004
Collagen IX is the prototype fibril-associated collagen with interruptions in triple helix. In human cartilage it covers collagen fibrils, but its putative cellular receptors have been unknown. The reverse transcription-PCR analysis of human fetal tissues suggested that based on their distribution all four collagen receptor integrins, namely alpha1beta1, alpha2beta1, alpha10beta1, and alpha11beta1, are possible receptors for collagen IX. Furthermore primary chondrocytes and chondrosarcoma cells express the four integrins simultaneously. Chondrosarcoma cells, as well as Chinese hamster ovary cells transfected to express alpha1beta1, alpha2beta1, or alpha10beta1 integrin as their only collage…
On the origin of Metazoan adhesion receptors: cloning of integrin alpha subunit from the sponge Geodia cydonium
1997
Integrins are prominent receptors known from vertebrates and the higher phyla of invertebrates. Until now, no evidence has been provided for the existence of integrins in the lowest Metazoa, the sponges (Porifera). We have isolated and characterized a cDNA clone encoding the alpha subunit of integrin from the marine sponge Geodia cydonium (GCINTEG). The open reading frame encodes a polypeptide of 1,086 residues (118 kDa). The intracellular domain features the sequence Tyr-Phe-x-Gly-Phe-Phe-x-Arg, which is different in one residue from the characteristic consensus pattern for integrin alpha subunits. We conclude that sponges, the oldest multicellular animal phylum, already utilize the struct…
Intracellular Na+ concentration influences short-term plasticity of glutamate transporter-mediated currents in neocortical astrocytes.
2012
Fast synaptic transmission requires a rapid clearance of the released neurotransmitter from the extracellular space. Glial glutamate transporters (excitatory amino acid transporters, EAATs) strongly contribute to glutamate removal. In this work, we investigated the paired-pulse plasticity of synaptically activated, glutamate transporter-mediated currents (STCs) in cortical layer 2/3 astrocytes. STCs were elicited by local electrical stimulation in layer 4 in the presence of ionotropic glutamate (AMPA and NMDA), GABAA, and GABAB receptor antagonists. In experiments with low [Na+]i (5 mM) intrapipette solution, STCs elicited by paired-pulse stimulation demonstrated paired-pulse facilitation (…
Role of Neutral Amino Acid Transport and Protein Breakdown for Substrate Supply of Nitric Oxide Synthase in Human Endothelial Cells
2003
Endothelial dysfunction is often associated with a relative substrate deficiency of the endothelial nitric oxide synthase (eNOS) in spite of apparently high intracellular arginine concentrations. For a better understanding of the underlying pathophysiological mechanisms, we aimed to characterize the intracellular arginine sources of eNOS. Our previous studies in human endothelial EA.hy926 cells suggested the existence of two arginine pools: pool I can be depleted by extracellular lysine, whereas pool II is not freely exchangeable with the extracellular space, but accessible to eNOS. In this study, we demonstrate that the eNOS accessible pool II is also present in human umbilical vein endoth…
Modulation of NMDA receptor function by cyclic AMP in cerebellar neurones in culture
2004
The signal transduction pathways involved in NMDA receptor modulation by other receptors remain unclear. cAMP could be involved in this modulation. The aim of this work was to analyse the contribution of cAMP to NMDA receptor modulation in cerebellar neurones in culture. Forskolin increases cAMP and results in increased intracellular calcium and cGMP that are prevented by blocking NMDA receptors. Similar effects were induced by two cAMP analogues, indicating that cAMP leads to NMDA receptor activation. It has been reported that phosphorylation of Ser897 of the NR1 subunit of NMDA receptors by cAMP-dependent protein kinase (PKA) activates the receptors. Forskolin increases Ser897 phosphoryla…
Ring size control in diorganotin sulphides by intramolecular SnN coordination
1992
Abstract The synthesis of intramolecularly coordinated organotin sulphides, [(Me2N CH2CH2CH2)2SnS]n (1) and [Me2NCH2CH2CH2Sn(Ph)S]n (2), is described. Compounds 1 and 2 are dimers in chloroform solution (n = 2). Compound 1 forms a centrosymmetric dimer with a planar rectangular Sn2S2 four-membered ring in its centre. The tin atoms show a distorted trans-cis-cis octahedral coordination by 2C, 2N and 2S. The tin-nitrogen distances are 2.810(3) and 3.158(5) A. Compound 1 can be regarded as a model substance for nucleophilic attack at penta-coordinate tin centres. Although the degree of intramolecular coordination of nitrogen to tin is temperature dependent, the four-membered Sn2Sn2 ring remain…
Femminismo islamico e cosmopolitismo
2021
The chapter introduces Islamic feminism as a movement with a focus on three study cases from Egypt (Omaima Abou-Bakr), Iran (Ziba Mir-Hosseini), and the United States (Amina Wadud). In my section, I claim that besides being a social commitment, Islamic feminism is a form of moral cosmopolitanism, for it is a global and transnational movement. The advocacy of Islamic feminists is rooted in local contexts, at the same time they are involved in empowering international networks which allow them to meet activists from other domains, enforce their projects, share their experiences and work together for achieving their goals. The name “cosmopolitan Islamic feminist” is not an oxymoron, since it d…
Activation of metabotropic glutamate receptors induces propagating network oscillations in the intact cerebral cortex of the newborn mouse.
2006
Activation of metabotropic glutamate receptors (mGluRs) with (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid (ACPD) elicited in the frontal or occipital pole of the intact cerebral cortex preparation of the newborn mouse (P0-P3) a transient oscillatory field potential activity in the frequency range of 11-14Hz. These oscillations propagated over the whole cortical hemisphere and were blocked by tetrodotoxin, indicating that action potentials are required for the generation of this activity. Blockade of GABA-A receptors with gabazine did not influence the ACPD-induced network activity, but the glycine antagonist strychnine caused a significant decrease in the frequency, amplitude and durat…
Calretinin/PSA-NCAM immunoreactive granule cells after hippocampal damage produced by kainic acid and DEDTC treatment in mouse.
2003
There is a dramatic increase in the number of lightly immunoreactive calretinin cells in the granular layer of the dentate gyrus of the mouse hippocampus 1 day after excitotoxic injury using kainic acid combined with the zinc chelator diethyldithiocarbamate. At 7 days after treatment, these cells are strongly immunoreactive for calretinin and for the polysialated form of the glycoprotein neural cell adhesion molecule (PSA-NCAM). The reexpression of calretinin and PSA-NCAM after treatment corresponds well with the loss of input from the damaged hilar mossy cells. These cells could be considered immature granule cells since they are immunoreactive to markers for immature cells such as PSA-NCA…
Proteomic Analyses Reveal an Acidic Prime Side Specificity for the Astacin Metalloprotease Family Reflected by Physiological Substrates
2011
Astacins are secreted and membrane-bound metalloproteases with clear associations to many important pathological and physiological processes. Yet with only a few substrates described their biological roles are enigmatic. Moreover, the lack of knowledge of astacin cleavage site specificities hampers assay and drug development. Using PICS (proteomic identification of protease cleavage site specificity) and TAILS (terminal amine isotopic labeling of substrates) degradomics approaches >3000 cleavage sites were proteomically identified for five different astacins. Such broad coverage enables family-wide determination of specificities N- and C-terminal to the scissile peptide bond. Remarkably, me…