Effects of glutaraldehyde fixation on the structure of tight junctions. A quantitative freeze-fracture analysis

1979 ◽  
Vol 68 (2) ◽  
pp. 160-172 ◽  
Author(s):  
B. Van Deurs ◽  
J.H. Luft
Keyword(s):  
Tight Junctions ◽  
Freeze Fracture ◽  
Fracture Analysis ◽  
Glutaraldehyde Fixation

scholarly journals A freeze-fracture study on the developing satellite cells of spinal ganglia in the chick embryo

1988 ◽  
Vol 46 (1) ◽  
pp. 6-9
Author(s):  
Claudio A. Ferraz de Carvalho ◽  
Ciro F. da Silva
Keyword(s):  
Chick Embryo ◽  
Gap Junctions ◽  
Tight Junctions ◽  
Small Groups ◽  
Satellite Cells ◽  
Freeze Fracture ◽  
Fracture Analysis ◽  
Spinal Ganglia ◽  
Pinocytotic Vesicles ◽  
Fracture Study

A freeze-fracture analysis of the satellite cells of spinal ganglia of the chick embryo was performed in 8 successive stages of development, from the 5th incubation day to hatching. The characteristic laminar disposition of the cells were first observed on the 7th day. Tight junctions were found at the 20th incubation day. Small groups or irregular aggregates of particles, but not gap junctions, were described on the 7th and 8th days. Pinocytotic vesicles were pointed out in the different stages considered.

scholarly journals Structural and Functional Regulation of Tight Junctions by RhoA and Rac1 Small GTPases

1998 ◽  
Vol 142 (1) ◽  
pp. 101-115 ◽  
Author(s):  
Tzuu-Shuh Jou ◽  
Eveline E. Schneeberger ◽  
W. James Nelson
Keyword(s):  
Tight Junctions ◽  
Spatial Organization ◽  
Mdck Cells ◽  
Protein Localization ◽  
Freeze Fracture ◽  
Tracer Diffusion ◽  
Small Gtpases ◽  
Dominant Negative ◽  
Solute Diffusion ◽  
Fence Function

Tight junctions (TJ) govern ion and solute diffusion through the paracellular space (gate function), and restrict mixing of membrane proteins and lipids between membrane domains (fence function) of polarized epithelial cells. We examined roles of the RhoA and Rac1 GTPases in regulating TJ structure and function in MDCK cells using the tetracycline repressible transactivator to regulate RhoAV14, RhoAN19, Rac1V12, and Rac1N17 expression. Both constitutively active and dominant negative RhoA or Rac1 perturbed TJ gate function (transepithelial electrical resistance, tracer diffusion) in a dose-dependent and reversible manner. Freeze-fracture EM and immunofluoresence microscopy revealed abnormal TJ strand morphology and protein (occludin, ZO-1) localization in RhoAV14 and Rac1V12 cells. However, TJ strand morphology and protein localization appeared normal in RhoAN19 and Rac1N17 cells. All mutant GTPases disrupted the fence function of the TJ (interdomain diffusion of a fluorescent lipid), but targeting and organization of a membrane protein in the apical membrane were unaffected. Expression levels and protein complexes of occludin and ZO-1 appeared normal in all mutant cells, although ZO-1 was more readily solubilized from RhoAV14-expressing cells with Triton X-100. These results show that RhoA and Rac1 regulate gate and fence functions of the TJ, and play a role in the spatial organization of TJ proteins at the apex of the lateral membrane.

Freeze-fracture analysis of membrane events during early neogenesis of cilia in Tetrahymena: changes in fairy-ring morphology and membrane topography

1983 ◽  
Vol 60 (1) ◽  
pp. 137-156
Author(s):  
L.A. Hufnagel
Keyword(s):  
Cell Division ◽  
Membrane Structure ◽  
Freeze Fracture ◽  
Fracture Analysis ◽  
Basal Bodies ◽  
Membrane Topography ◽  
Fairy Rings ◽  
Dividing Cells ◽  
Cortical System ◽  
Membrane Particle

A freeze-fracture analysis of early neogenesis of somatic and oral cilia of Tetrahymena was conducted using exponentially grown cultures and also cells induced to undergo oral reorganization. In this report, presumptive ciliary domains (PCDs), sites of future outgrowth of somatic cilia, are identified and their membrane structure is described in detail. The fairy ring, an array of membrane particles that occurs within the PCD and appears to be a precursor of the ciliary necklace, is described. A sequence of early stages in the formation of the ciliary necklace of somatic cilia is deduced from topographical information and membrane particle arrangements and numbers. Evidence is presented that basal bodies are seated at the cell surface prior to initiation of necklace assembly and a possible role for the basal body in necklace assembly is suggested. In dividing cells, new oral cilia grow out prior to orientation of cilia-parasomal sac complexes relative to cell axes. In dividing cells and during oral reorganization, new cilia also develop prior to their alignment into membranelles. Thus, growth of cilia is independent of their spatial orientation. Fairy rings were not observed during oral reorganization. During cell division, proliferation of new cilia is accompanied by the formation of a network of junctions between a cortical system of membranous cisternae, the cortical ‘alveoli’. These interalveolar junctions may serve as tracks for early positioning and orientation of new oral basal bodies.

Freeze–fracture analysis of muscle plasma membrane in Becker's muscular dystrophy

1994 ◽  
Vol 20 (5) ◽  
pp. 487-494 ◽  
Author(s):  
S. Shibuya ◽  
Y. Wakayama ◽  
T. Jimi ◽  
H. Oniki ◽  
T. Kobayashi ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Muscular Dystrophy ◽  
Freeze Fracture ◽  
Fracture Analysis ◽  
Muscle Plasma Membrane

Tight junctions in Gerbil von Ebner's Gland: Horseradish peroxidase and freeze-fracture studies

2015 ◽  
Vol 78 (3) ◽  
pp. 213-219 ◽  
Author(s):  
Anthony Y. Huang ◽  
Ming-Huei Chen ◽  
Sandy Y. Wu ◽  
Kuo-Shyan Lu
Keyword(s):  
Horseradish Peroxidase ◽  
Tight Junctions ◽  
Freeze Fracture

scholarly journals Freeze-fracture analysis of the membrane lesion of human complement.

1983 ◽  
Vol 97 (3) ◽  
pp. 618-626 ◽  
Author(s):  
J Tranum-Jensen ◽  
S Bhakdi
Keyword(s):  
Transmembrane Protein ◽  
Freeze Fracture ◽  
Fracture Analysis ◽  
Membrane Insertion ◽  
Membrane Bilayer ◽  
Face Ring ◽  
Circular Structure ◽  
Protein Channel ◽  
Classical Ring ◽  
Membrane Lesion

The structure and membrane insertion of the human C5b-9(m) complex, generated by lysis of antibody-coated sheep erythrocytes with whole human serum under conditions where high numbers of classical ring-shaped lesions form, were studied in single and complementary freeze-fracture replicas prepared by unidirectional and rotary shadowing. The intramembrane portion of the C5b-9(m) cylinder was seen on EF-faces as an elevated, circular structure. In nonetched fractures it appeared as a solid stub; in etched fractures a central pit confirmed the existence of a central, water-filled pore in the molecule. Complementary replicas showed that each EF-face ring corresponded to a hole in the lipid plateau of the PF-face. Etched fractures of proteolytically stripped membranes revealed the extramembrane annulus of the C5b-9(m) cylinder on ES-faces and putative internal openings on PS-faces. Allowing for the measured thickness of deposited Pt/C, the dimensions of EF-face rings and ES-face annuli conformed to anticipations derived from negatively stained preparations. Our results support the concept that the hollow cylindrical C5b-9(m) complex penetrates into the inner leaflet of the target erythrocyte membrane bilayer, forming a stable transmembrane protein channel.

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