| 1. |
- Franke, W W, et al.
(författare)
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Desmosomes--dual junctional principles of intra- and supracellular order in epithelial differentiation and tissue formation
- 1994
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Ingår i: Verhandlungen der Deutschen Gesellschaft fur Pathologie. - 0070-4113. ; 78, s. 8-14
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Tidskriftsartikel (refereegranskat)abstract
- The cells of most normal and malignantly growing tissues are connected by "adhering junctions", i.e. distinct sites of "homotypic" contact between the plasma membranes of two cells of the same or a similar kind, associated on the cytoplasmic side by a dense plaque at which often bundles of cytoskeletal filaments anchor. Of the various types of adhering junctions desmosomes are characteristic of epithelia and carcinomas but also occur in some other cell types. Their molecular components have recently been identified and characterized by cDNA-cloning and sequencing. Unexpectedly, the molecular complement of desmosomes has been found to show certain differences in different epithelia, with particularly complex patterns in stratified squamous epithelia as well as in tumors and cultured cell lines derived therefrom. In addition, molecular principles important in the assembly of desmosomes and in the specific anchorage of intermediate-sized filaments (IFs) at desmosomal plaques have been elucidated. The possible value of cell type-specific isoforms of desmosomal components as markers for the subtyping of carcinomas and the role of desmosomal cadherins during invasion and metastasis of carcinomas are discussed.
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| 2. |
- Schmidt, A, et al.
(författare)
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Desmosomes and cytoskeletal architecture in epithelial differentiation: cell type-specific plaque components and intermediate filament anchorage
- 1994
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Ingår i: European Journal of Cell Biology. - 0171-9335. ; 65:2, s. 229-245
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Tidskriftsartikel (refereegranskat)abstract
- Among the diverse kinds of intercellular, plaque-bearing, cadherin-containing junctions, desmosomes (maculae adhaerentes) represent a major type characterized by the presence of specific transmembrane glycoproteins, i.e. desmosomal cadherins of the desmoglein and desmocollin categories, and the cytoplasmic plaque proteins, desmoplakin I and plakoglobin. Recent studies, however, have shown that the composition of desmosomes is not identical in the various normal and tumorous desmosome-forming tissues and cell cultures, including diverse forms of epithelia and carcinomas, meningothelia and meningiomas, myocardium and the lymph node follicle reticulum. Desmosomes can differ in their specific complement of desmogleins, Dsg1-3, and desmocollins, Dsc1a-3b, as well as in the additional presence and in their relative amounts of certain accessory plaque proteins such as desmoplakin II and plakophilin 1, a basic member of the larger plakoglobin family of proteins ("band 6 protein"). Assembly and function of desmosomes are effected by the interaction of the specific complement of desmosomal cadherins with certain cytoplasmic proteins. In particular, the cytoplasmic portions ("tails") of the desmosomal cadherins contain certain domains and amino acid sequence motifs, identified by mutagenesis and transfection assays, that are essential elements in desmosome formation, notably the assembly of plaque proteins, and in the site-specific anchorage of intermediate-sized filaments (IFs) of the cytoskeleton, thereby contributing to the specific intracellular as well as supracellular, i.e. tissue, architecture.
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| 3. |
- Szöcs, G., et al.
(författare)
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Species discrimination in five species of winter-flying geometrids (Lepidoptera) based on chirality of semiochemicals and flight season
- 1993
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Ingår i: Journal of Chemical Ecology. - 0098-0331. ; 19:11, s. 2721-2735
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Tidskriftsartikel (refereegranskat)abstract
- Enantiomer separation of (6 Z,9 Z)-cis-3,4-epoxynonadecadiene and (3 Z,9 Z)-cis-6,7-epoxynonadecadiene could be achieved using chiral high-resolution gas chromatography and a cyclodextrin-bond column. (3 Z,9 Z)-(6 R,7 S)-Epoxynonadecadiene was identified from ovipositor extracts of Colotois pen-Naria, while in Erannis defoliaria the 6 S,7 R-enantiomer was found. In field trapping tests pure synthetic enantiomers caught only conspecific males of these species. (3 Z,6 Z,9 Z)-Nonadecatriene was found in both species, while the presence of (3 Z,6 Z,9 Z)-heneicosatriene was indicated in C. Pennaria only. A 10:10:3 blend of (3 Z,9 Z)-(6 R,7 S)-epoxynonadecadiene, (3 Z,6 Z,9 Z)-heneicosatriene, and (3 Z,6 Z,9 Z)-nonadecatriene was found to be optimal for catching C. Pennaria, while E. Defoliaria males were optimally caught by a 1:1 mixture of (3 Z,9 Z)-(6 S,7 R)-epoxynonadecadiene and (3 Z,6 Z,9 Z)-nona-decatriene. (6 Z,9 Z)-(3 S,4 R)-Epoxynonadecadiene was identified from ovipositor extracts of Agriopis (Erannis) aurantiaria. In field tests the pure enantiomer proved to be a highly specific sex attractant for both the late autumn/early winter flying A. Aurantiaria and the late winter/early spring flying A. Leucophearia. Males of Agriopis marginaria, which fly in late winter/early spring, were attracted to (3 Z,9 Z)-(6 S,7 R)-epoxynonadecadiene. The addition of (3 Z,6 Z,9 Z)-nonadecatriene to the S,R-enantiomer increased captures. Optimal catches were recorded with a 10:3 epoxide-hydrocarbon blend. Enantiomer specificity in all species was confirmed in EAG measurements.
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| 4. |
- Tóth, Miklos, et al.
(författare)
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Pheromonal Production of and Response to Optically Active Epoxydienes in Some Ceometrid Moths (Lepidoptera: Geometridae)
- 1994
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Ingår i: Zeitschrift fur Naturforschung - Section C Journal of Biosciences. - : Walter de Gruyter GmbH. - 0939-5075. ; 49:7-8, s. 516-521
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Tidskriftsartikel (refereegranskat)abstract
- In, pheromone extracts of calling female Chiasma clathrata, L. (Lepidoptera: Geometridae), a defoliator pest of alfalfa, (Z,Z,Z)-3,6,9–heptadecatriene and (Z,Z)-6,9–cis-3,4–epoxyhepta-decadiene was identified. Chiral gas chromatography using a modified cyclodextrin and synthetic reference samples proved the natural epoxide to show (3 R.4 S)-configuration. In field trapping tests, only the pure (3/R,4S)-enantiomer of the epoxide attracted males. The addition of the triene component was synergistic. Males of the sympatric species Tephrina arenaceciria Hbn. (Lepidoptera: Geometridae) were caught only in traps with baits containing the (3S,4R)-enantiomer [together with a previously described minor component, (Z,Z)-3,9–cis-6,7–epoxyheptadecadiene], In trapping tests conducted iNADifferent biotope Abraxas grossu-lariata, L. (Lepidoptera: Geometridae) males were attracted by the (3S,4R)-enantiomer, whereas the (3/L4S)-enantiomer attracted a close relative. Abraxas sylvata Scop. (Lepidoptera: Geometridae). The present results suggest that one of the key mechanisms responsible for pheromone specificity among both the two alfalfa geometrids and the two Abraxas species in their respective biotops, may be the use of different enantiomers of the same polyene-derived epoxide as a sex pheromone component. It is probable that this discrimination mechanism is widespread among moth species utilizing epoxide pheromone components.
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