Search results for "skeleton"
showing 10 items of 418 documents
Analysis of the axial filament in spicules of the demosponge Geodia cydonium: different silicatein composition in microscleres (asters) and megascler…
2007
The skeleton of the siliceous sponges (Porifera: Hexactinellida and Demospongiae) is supported by spicules composed of bio-silica. In the axial canals of megascleres, harboring the axial filaments, three isoforms of the enzyme silicatein (-alpha, -beta and -gamma) have been identified until now, using the demosponges Tethya aurantium and Suberites domuncula. Here we describe the composition of the proteinaceous components of the axial filament from small spicules, the microscleres, in the demosponge Geodia cydonium that possesses megascleres and microscleres. The morphology of the different spicule types is described. Also in G. cydonium the synthesis of the spicules starts intracellularly …
Differential Distribution of Harmonin Isoforms and Their Possible Role in Usher-1 Protein Complexes in Mammalian Photoreceptor Cells
2003
PURPOSE. Human Usher syndrome is the most common form of combined deafness and blindness. Usher type I (USH1), the most severe form, is characterized by profound congenital deafness, constant vestibular dysfunction, and prepubertal onset retinitis pigmentosa. Previous studies have shown that the USH1-proteins myosin VIIa, harmonin, and cadherin 23 interact and form a functional network during hair cell differentiation in the inner ear. The purpose of the present study was to analyze the molecular and cellular functions of these USH1 proteins in the mammalian retina. METHODS. Antibodies to USH1 proteins were generated and used in Western blot analysis of subcellular photoreceptor fractions a…
Using skeleton and Hough transform variant to correct skew in historical documents
2020
International audience; As a main part of several document analysis systems, Skew estimation represents one of the major research challenges, particularly in case of historical documents exploration. In this paper, we propose an original skew angle detection and correction technique. Morphological Skeleton is introduced to considerably diminish the amount of data by eliminating the redundant pixels and preserving only the central curves of the image components. Next, the proposed method uses Progressive Probabilistic Hough Transform (PPHT) to find image lines. At the end, a specific procedure is applied in order to measure the global skew angle of the document image from these identified li…
Proper synaptic vesicle formation and neuronal network activity critically rely on syndapin I
2011
Synaptic transmission relies on effective and accurate compensatory endocytosis. F-BAR proteins may serve as membrane curvature sensors and/or inducers and thereby support membrane remodelling processes; yet, their in vivo functions urgently await disclosure. We demonstrate that the F-BAR protein syndapin I is crucial for proper brain function. Syndapin I knockout (KO) mice suffer from seizures, a phenotype consistent with excessive hippocampal network activity. Loss of syndapin I causes defects in presynaptic membrane trafficking processes, which are especially evident under high-capacity retrieval conditions, accumulation of endocytic intermediates, loss of synaptic vesicle (SV) size cont…
On the photorelease of nitric oxide by nitrobenzene derivatives: A CASPT2//CASSCF model
2022
Nitroaromatic compounds can photorelease nitric oxide after UV absorption. The efficiency of the photoreaction depends on the molecular structure, and two features have been pointed out as particularly important for the yield of the process: the presence of methyl groups at the ortho position with respect to the nitro group and the degree of conjugation of the molecule. In this paper, we provide a theoretical characterization at the CASPT2//CASSCF (complete active space second-order perturbation theory//complete active space self-consistent field) level of theory of the photorelease of NO for four molecules derived from nitrobenzene through the addition of ortho methyl groups and/or the el…
Usher syndrome: molecular links of pathogenesis, proteins and pathways.
2006
Contains fulltext : 50437.pdf (Publisher’s version ) (Closed access) Usher syndrome is the most common form of deaf-blindness. The syndrome is both clinically and genetically heterogeneous, and to date, eight causative genes have been identified. The proteins encoded by these genes are part of a dynamic protein complex that is present in hair cells of the inner ear and in photoreceptor cells of the retina. The localization of the Usher proteins and the phenotype in animal models indicate that the Usher protein complex is essential in the morphogenesis of the stereocilia bundle in hair cells and in the calycal processes of photoreceptor cells. In addition, the Usher proteins are important in…
Isolation and characterization of a 60-70-kD plasma membrane glycoprotein involved in the contact-dependent inhibition of growth
1990
Previous studies have shown that plasma membrane compounds are involved in the contact-dependent inhibition of growth of human diploid fibroblasts. The purification of the active plasma membrane glycoprotein is described in this report. The glycoprotein has an apparent molecular mass of 60-70 kD and, due to differential sialylation, isoelectric points between pH 5.5. and 6.2. Treatment with sialidase yielded one spot in two-dimensional gel electrophoresis with an isoelectric point of 6.3. After removal of the N-glycosidically linked oligosaccharide chains, the apparent molecular mass is reduced by approximately 22 kD. Treatment was diluted NaOH, which removes the O-glycosidically linked por…
Involvement of actin-containing microfilaments in HSV-induced cytopathology and the influence of inhibitors of glycosylation.
1986
Two and a half hours after infection with a high dose of different strains of HSV-1 which induce rounding of cells, breakdown of actin containing microfilaments can be observed. At the periphery of the cell, actin containing knob-like protuberances were visible. Later on, actin seems to be located exclusively on the surface of cells. Observations were done by immunofluorescence microscopy, scanning electron-microscopy and immunoperoxidase staining of ultrathin sections. The envelope of HSV appears to be stained by anti-actin. Strain IES produces rounding of cells at a high dose of infection before fusion proceeds at 37 degrees C. Similar alterations were not observed with the fusing strains…
Differential expression and glycosylation of proteins in the rat ileal epithelium in response to Echinostoma caproni infection.
2013
Echinostoma caproni (Trematoda: Echinostomatidae) is an intestinal trematode that has been used as experimental model to investigate the factors determining the expulsion of intestinal helminths. We analyze the changes in the protein expression and glycosylation induced by E. caproni in Wistar rat, a host of low compatibility in which the parasites are rapidly rejected. To determine the changes in protein expression, two-dimensional difference gel electrophoresis was employed using protein extracts from the intestine of naïve and infected rats. The patterns of glycosylation were analyzed by lectin blotting. Those spots showing differential expression or glycosylation were analyzed by mass s…
Purification and evaluation of large clostridial cytotoxins that inhibit small GTPases of Rho and ras subfamilies
2000
Publisher Summary This chapter discusses the purification and evaluation of large clostridia cytotoxins (LCTs) that inhibit small guanosine 5'-triphosphates (GTPases) of Rho and Ras subfamilies. LCTs are glycosyltransferases that inactivate GTPases of the Rho and Ras subfamilies by covalently coupling a sugar moiety (mostly glucose) to the conserved threonine residue in region switch 1 of the GTPases (T35 in Ras). This glycosylation functionally inactivates the GTPases leading to the collapse of the actin cytoskeleton and ultimately induces apoptosis of the cells. Small GTP-binding proteins are key players in the regulation of signal transducing networks of eukaryotic cells. Their regulator…