TY  - JOUR
A1  - Scheer, Ulrich
A1  - Kartenbeck, Jürgen
A1  - Trendelenburg, Michael F.
A1  - Stadler, Joachim
A1  - Franke, Werner W.
T1  - Experimental disintegration of the nuclear envelope: evidence for pore-connecting fibrils
N2  - The disintegration of the nuclear envelope has been examined in nuclei and nuclear envelopes isolated from amphibian oocytes and rat liver tissue, using different electron microscope techniques (ultrathin sections and negatively or positively stained spread preparations). Various treatments were studied, including disruption by surface tension forces, very low salt concentrations, and non ionic detergents such as Triton X-lOO and Nonidet P-40. The high local stability of the cylinders of nonmembranous pore complex material is emphasized. As progressive disintegration occurred in the membrane regions, a network of fibrils became apparent which interconnects the pore complexes and is distinguished from the pore complexassociated intranuclear fibrils. This network might correspond to an indistinct lamella, about 15 - 20 nm thick, located at the level of the inner nuclear membrane, which is recognized in thin sections to bridge the interpore distances. With all disintegration treatments a somewhat higher susceptibility of the outer nuclear membrane is notable, but a selective removal does not take place. Final stages of disintegration are generally characterized by the absence of identifiable, membrane- like structures. Analysis of detergent-treated nuclei and nuclear membrane fractions shows almost complete absence of lipid components but retention of significant amount of glycoproteins with a typical endomembrane-type carbohydrate pattern. Various alternative interpretations of these observations are discussed. From the present observations and those of Aaronson and Blobel (1,2), we favor the notion that threadlike intrinsic membrane components are stabilized by their attachment to the pore complexes, and perhaps also to peripheral nuclear structures, and constitute a detergent-resistant, interpore skeleton meshwork.
Y1  - 1976
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-39735
ER  - 
TY  - JOUR
A1  - Franke, Werner W.
A1  - Kartenbeck, Jürgen
A1  - Krien, S.
A1  - VanderWoude, W. J.
A1  - Scheer, Ulrich
A1  - Morré, D. J.
T1  - Inter- and intracisternal elements of the Golgi apparatus: A system of membrane-to-membrane cross-links
N2  - Electron opaque cross-bridge structures span the inter- and intracisternal spaces and provide membrane-to-membrane connections between adjacent cisternae of dictyosomes of pollen tubes of Clivia and Lilium. Additionally, the classic intercisternal rods, characteristic of intercisternal regions near the maturing face of dictyosomes, are connected with the adjacent membranes through similar cross-bridge elements. We suggest that these structural links are responsible for maintaining the flattened appearance of the central parts of Golgi apparatus cisternae as well as for the coherence of cisternae within the stack. Observations on other plant (e.g. microsporocytes of Canna) and animal cells (e.g. rodent liver and hepatoma cells, newt spermatocytes) show that such an array of membrane cross-links is a universal feature of Golgi apparatus architecture. The cross-bridges appear as part of the complex "zone of exclusion" which surrounds dictyosomes, entire Golgi apparatus and Golgi apparatus equivalents in a variety of cell types.
KW  - Golgi apparatus
KW  - Membranes
KW  - Cross-bridges
KW  - Electron microscopy
Y1  - 1972
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-39514
ER  - 
TY  - JOUR
A1  - Franke, Werner W.
A1  - Kartenbeck, Jürgen
A1  - Zentgraf, Hanswalter
A1  - Scheer, Ulrich
A1  - Falk, Heinz
T1  - Membrane-to-membrane cross-bridges. A means to orientation and interaction of membrane faces
N2  - No abstract available
Y1  - 1971
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-32122
ER  -