Search results for "Transmembrane"
showing 10 items of 299 documents
A novel Usher protein network at the periciliary reloading point between molecular transport machineries in vertebrate photoreceptor cells.
2008
Contains fulltext : 69178.pdf (Publisher’s version ) (Closed access) The human Usher syndrome (USH) is the most frequent cause of combined deaf-blindness. USH is genetically heterogeneous with at least 12 chromosomal loci assigned to three clinical types, USH1-3. Although these USH types exhibit similar phenotypes in human, the corresponding gene products belong to very different protein classes and families. The scaffold protein harmonin (USH1C) was shown to integrate all identified USH1 and USH2 molecules into protein networks. Here, we analyzed a protein network organized in the absence of harmonin by the scaffold proteins SANS (USH1G) and whirlin (USH2D). Immunoelectron microscopic anal…
Cystic Fibrosis Transmembrane Conductance Regulator Interacts with Multiple Immunoglobulin Domains of Filamin A
2010
Mutations of the chloride channel cystic fibrosis transmembrane conductance regulator (CFTR) that impair its apical localization and function cause cystic fibrosis. A previous report has shown that filamin A (FLNa), an actin-cross-linking and -scaffolding protein, interacts directly with the cytoplasmic N terminus of CFTR and that this interaction is necessary for stability and confinement of the channel to apical membranes. Here, we report that the CFTR N terminus has sequence similarity to known FLNa-binding partner-binding sites. FLNa has 24 Ig (IgFLNa) repeats, and a CFTR peptide pulled down repeats 9, 12, 17, 19, 21, and 23, which share sequence similarity yet differ from the other FLN…
Non-cross-linked porcine-based collagen I-III membranes do not require high vascularization rates for their integration within the implantation bed: …
2012
There are conflicting reports concerning the tissue reaction of small animals to porcine-based, non-cross-linked collagen I-III membranes/matrices for use in guided tissue/bone regeneration. The fast degradation of these membranes/matrices combined with transmembrane vascularization within 4 weeks has been observed in rats compared with the slow vascularization and continuous integration observed in mice. The aim of the present study was to analyze the tissue reaction to a porcine-based non-cross-linked collagen I-III membrane in mice. Using a subcutaneous implantation model, the membrane was implanted subcutaneously in mice for up to 60 days. The extent of scaffold vascularization, tissue …
Type-II Transmembrane Prolyl Dipeptidases and Matrix Metalloproteinases in Membrane Vesicles of Active Endothelial Cells
2006
Endothelia cells in sparse culture are migratory and increase the production of gelatinases of serine- and metallo-classes in membrane vesicles. Collectively, proteases associated with membrane vesicles degrade extracellular matrix components including type-I and type-IV collagens, laminin and fibronectin. Inhibitor studies suggest the existence of small gelatinases that were derived from these serine- and metallo-proteases. Thus, further studies are warranted to demonstrate the cooperative action of metallo- and serine proteases on cell surfaces and in extracellular vesicles during endothelial cell migration in 3D collagenous matrices, and potential proteolytic activation mechanism for the…
A 2-D model of electrodialysis stacks including the effects of membrane deformation
2021
Abstract Membrane-based processes have gained a relevant role in many engineering applications. Much effort has been devoted to thoroughly understand the fundamental phenomena behind them. However, membrane deformation has been taken into consideration only recently, although much evidence has shown its impacts in many applications. This work presents a novel 2-D, multi-scale, semi-empirical process model able to predict the behavior and the performance of Electrodialysis (ED) systems in cross-flow configurations in the presence and absence of local membrane deformations. The model exploits the results and the simulation approaches of previous fluid-structure investigations performed by the…
Molecular cloning and primary structure of a Rhesus (Rh)-like protein from the marine sponge Geodia cydonium
1997
In humans, the 30,000 M(r) Rhesus (Rh) polypeptide D (RhD) is a dominant antigen (Ag) of the Rh blood group system. To date, an Rh-like protein has been found in chimpanzees, gorillas, gibbons, and rhesus monkeys. Related to the 30,000 M(r) Rh Ag protein are two polypeptides of 50,000 M(r), the human 50,000 M(r) Rh Ag and the RhD-like protein from Caenorhabditis elegans. The function of all these proteins is not sufficiently known. Here we characterize a cDNA clone (GCRH) encoding a putative 57,000 M(r) polypeptide from the marine sponge Geodia cydonium, which shares sequence similarity both to the RhD Ag and the Rh50 glycoprotein. The sponge Rh-like protein comprises 523 aa residues; hydro…
mp23, a Theileria parva transmembrane protein with homology to the protein disulfide isomerase family
2002
The protozoan parasite Theileria parva (Apicomplexa) causes the bovine disease East Coast Fever in endemic areas in Subsaharan Africa. The intralymphocytic schizont stage is largely responsible for the pathogenicity and induces a transformed phenotype in host cells [1]. Current evidence supports a model in which the schizont perturbs the immune response by inducing production of cytokines and stimulating the growth of parasitized cells [2]. We were interested to identify parasite proteins involved in parasite/host interaction and have described earlier a screening procedure for identification of schizont stage-exported proteins based on cell-free expression of cDNA and testing for transloca…
Alpha-toxin of Staphylococcus aureus
1991
Alpha-toxin, the major cytotoxic agent elaborated by Staphylococcus aureus, was the first bacterial exotoxin to be identified as a pore former. The protein is secreted as a single-chain, water-soluble molecule of Mr 33,000. At low concentrations (less than 100 nM), the toxin binds to as yet unidentified, high-affinity acceptor sites that have been detected on a variety of cells including rabbit erythrocytes, human platelets, monocytes and endothelial cells. At high concentrations, the toxin additionally binds via nonspecific absorption to lipid bilayers; it can thus damage both cells lacking significant numbers of the acceptor and protein-free artificial lipid bilayers. Membrane damage occu…
Nimrod, a Putative Phagocytosis Receptor with EGF Repeats in Drosophila Plasmatocytes
2007
SummaryThe hemocytes, the blood cells of Drosophila, participate in the humoral and cellular immune defense reactions against microbes and parasites [1–8]. The plasmatocytes, one class of hemocytes, are phagocytically active and play an important role in immunity and development by removing microorganisms as well as apoptotic cells. On the surface of circulating and sessile plasmatocytes, we have now identified a protein, Nimrod C1 (NimC1), which is involved in the phagocytosis of bacteria. Suppression of NimC1 expression in plasmatocytes inhibited the phagocytosis of Staphylococcus aureus. Conversely, overexpression of NimC1 in S2 cells stimulated the phagocytosis of both S. aureus and Esc…
Recovery of human fibroblasts from attack by the pore-forming alpha-toxin of Staphylococcus aureus.
1994
When applied at low concentrations (10 micrograms/ml), staphylococcal alpha-toxin generates a small channel in keratinocyte and lymphocyte membranes that permits selective transmembrane flux of monovalent ions. Here we show that a moderate concentration (1-50 micrograms/ml) of alpha-toxin similarly produces a small pore in membranes of human fibroblasts. This process leads to rapid leakage of K+ and to a drop in cellular ATP to 10-20% of normal levels in 2 h. In the presence of medium supplemented with serum and at pH 7.4, the cells are able to recover from toxin attack, so that normal levels of K+ and ATP are reached after 6-8 h at 37 degrees C. The repair process is dependent on the prese…