Membrane changes associated with mucus production by intestinal goblet cells

1978 ◽  
Vol 33 (1) ◽  
pp. 301-316
Author(s):  
J.G. Swift ◽  
T.M. Mukherjee
Keyword(s):  
Plasma Membrane ◽  
Membrane Proteins ◽  
Membrane Fusion ◽  
Thin Section ◽  
Structural Organization ◽  
Freeze Fracture ◽  
Goblet Cells ◽  
Mucus Production ◽  
Membrane Reorganization ◽  
Membrane Changes

Changes in the structural organization of membranes of mucous bodies and the plasma membrane that occur during mucus production in goblet cells of rat rectum have been studied by thin-section and freeze-fracture techniques. Immature mucous bodies are bounded by a trilaminar membrane and fracture faces of the membrane have randomly distributed intramembrane particles. During maturation, mucous bodies become packed tightly together and changes in the structure of their membranes include (1) fusion of apposing membranes of adjacent bodies to form a pentalaminar structure, (2) a reduction in the density of particles on membrane fracture faces, and (3) exclusion of particles from regions of membrane apposition. Some trilaminar membranes of mucous bodies fuse with the lumenal plasma membrane to form a pentalaminar structure. Sites of apposition between mucous body membranes and the lumenal plasma membrane are seen as particle-cleared bulges on fracture faces of the plasma membrane. Our results indicate that membrane reorganization associated with mucous production in goblet cells includes a reduction and redistribution of some membrane proteins and that membrane fusion occurs between portions of membranes from which proteins have been displaced.

scholarly journals Phagocytosis of bacteria by polymorphonuclear leukocytes: a freeze-fracture, scanning electron microscope, and thin-section investigation of membrane structure

1978 ◽  
Vol 76 (1) ◽  
pp. 158-174 ◽  
Author(s):  
PL Moore ◽  
HL Bank ◽  
NT Brissie ◽  
SS Spicer
Keyword(s):  
Plasma Membrane ◽  
Electron Microscope ◽  
Membrane Fusion ◽  
Thin Section ◽  
Membrane Structure ◽  
Freeze Fracture ◽  
Vacuole Membrane ◽  
Attachment Sites ◽  
Pmn Leukocytes ◽  
Scanning Electron

The changes in membrane structure of rabbit polymorphonuclear (PMN) leukocytes during bacterial phagocytosis was investigated with scanning electron microscope (SEM), thin-section, and freeze-fracture techniques. SEM observations of bacterial attachment sites showed the involvement of limited areas of PMN membrane surface (0.01-0.25μm(2)). Frequently, these areas of attachment were located on membrane extensions. The membrane extensions were present before, during, and after the engulfment of bacteria, but were diminished in size after bacterial engulfment. In general, the results obtained with SEM and thin-section techniques aided in the interpretation of the three-dimensional freeze-fracture replicas. Freeze-fracture results revealed the PMN leukocytes had two fracture faces as determined by the relative density of intramembranous particles (IMP). Membranous extensions of the plasma membrane, lysosomes, and phagocytic vacuoles contained IMP's with a distribution and density similar to those of the plasma membrane. During phagocytosis, IMPs within the plasma membrane did not undergo a massive aggregation. In fact, structural changes within the membranes were infrequent and localized to regions such as the attachment sites of bacteria, the fusion sites on the plasma membrane, and small scale changes in the phagocytic vacuole membrane during membrane fusion. During the formation of the phagocytic vacuole, the IMPs of the plasma membrane appeared to move in with the lipid bilayer while maintaining a distribution and density of IMPs similar to those of the plasma membranes. Occasionally, IMPs were aligned to linear arrays within phagocytic vacuole membranes. This alignment might be due to an interaction with linearly arranged motile structures on the side of the phagocytic vacuole membranes. IMP-free regions were observed after fusion of lysosomes with the phagocytic vacuoles or plasma membrane. These IMP-free areas probably represent sites where membrane fusion occurred between lysosomal membrane and phagocytic vacuole membrane or plasma membrane. Highly symmetrical patterns of IMPs were not observed during lysosomal membrane fusion.

Particle Movement in Heliozoan Axopods Associated with Lateral Displacement of H ighly Ordered Membrane Domains

1976 ◽  
Vol 31 (3-4) ◽  
pp. 190-194 ◽  
Author(s):  
Christian F. Bardele
Keyword(s):  
Plasma Membrane ◽  
Membrane Proteins ◽  
Membrane Fusion ◽  
Lateral Displacement ◽  
Freeze Fracture ◽  
Motive Force ◽  
Membrane Domains ◽  
Particle Movement ◽  
Peripheral Membrane Proteins

Abstract Freeze-fracture studies reveal that extrusive organelles displaying saltatory particle movements in centrohelidian axopod are attached to highly ordered domains within the plasma membrane. It is postulated that the motive force for lateral displacement of these membrane domains with the adhering organelle is located immediately underneath the plasma membrane being either part of the peripheral membrane proteins or attached filaments alined parallel to the axopodial micro­ tubules. The attachment domain is interpreted organelle discharge by membrane fusion.

Deformation of Yeast Plasma Membrane by Ethidium Bromide

1988 ◽  
Vol 46 ◽  
pp. 254-255
Author(s):  
E. Keyhani
Keyword(s):  
Plasma Membrane ◽  
Thin Section ◽  
Ethidium Bromide ◽  
Freeze Fracture ◽  
Mutagenic Effect ◽  
Yeast Cells ◽  
Hydrophobic Region ◽  
Thin Section Electron Microscopy ◽  
Section Electron ◽  
Deep Pits

The mutagenic effect of ethidium bromide on the mitochondrial DNA is well established. Using thin section electron microscopy, it was shown that when yeast cells were grown in the presence of ethidium bromide, besides alterations in the mitochondria, the plasma membrane also showed alterations consisting of 75 to 110 nm-deep pits. Furthermore, ethidium bromide induced an increase in the length and number of endoplasmic reticulum and in the number of intracytoplasmic vesicles.Freeze-fracture, by splitting the hydrophobic region of the membrane, allows the visualization of the surface view of the membrane, and consequently, any alteration induced by ethidium bromide on the membrane can be better examined by this method than by the thin section method.Yeast cells, Candida utilis. were grown in the presence of 35 μM ethidium bromide. Cells were harvested and freeze-fractured according to the procedure previously described.

scholarly journals Endocytosis of synaptic vesicle membrane at the frog neuromuscular junction.

1984 ◽  
Vol 98 (2) ◽  
pp. 685-698 ◽  
Author(s):  
T M Miller ◽  
J E Heuser
Keyword(s):  
Plasma Membrane ◽  
Synaptic Vesicle ◽  
Thin Section ◽  
Nerve Terminal ◽  
Motor Nerve ◽  
Freeze Fracture ◽  
Frog Neuromuscular Junction ◽  
Vesicle Membrane ◽  
Coated Pits ◽  
Active Zones

Frog nerve-muscle preparations were quick-frozen at various times after a single electrical stimulus in the presence of 4-aminopyridine (4-AP), after which motor nerve terminals were visualized by freeze-fracture. Previous studies have shown that such stimulation causes prompt discharge of 3,000-6,000 synaptic vesicles from each nerve terminal and, as a result, adds a large amount of synaptic vesicle membrane to its plasmalemma. In the current experiments, we sought to visualize the endocytic retrieval of this vesicle membrane back into the terminal, during the interval between 1 s and 2 min after stimulation. Two distinct types of endocytosis were observed. The first appeared to be rapid and nonselective. Within the first few seconds after stimulation, relatively large vacuoles (approximately 0.1 micron) pinched off from the plasma membrane, both near to and far away from the active zones. Previous thin-section studies have shown that such vacuoles are not coated with clathrin at any stage during their formation. The second endocytic process was slower and appeared to be selective, because it internalized large intramembrane particles. This process was manifest first by the formation of relatively small (approximately 0.05 micron) indentations in the plasma membrane, which occurred everywhere except at the active zones. These indentations first appeared at 1 s, reached a peak abundance of 5.5/micron2 by 30 s after the stimulus, and disappeared almost completely by 90 s. Previous thin-section studies indicate that these indentations correspond to clathrin-coated pits. Their total abundance is comparable with the number of vesicles that were discharged initially. These endocytic structures could be classified into four intermediate forms, whose relative abundance over time suggests that, at this type of nerve terminal, endocytosis of coated vesicles has the following characteristics: (a) the single endocytotic event is short lived relative to the time scale of two minutes; (b) earlier forms last longer than later forms; and (c) a single event spends a smaller portion of its lifetime in the flat configuration soon after the stimulus than it does later on.

scholarly journals Control of membrane fusion in exocytosis. Physiological studies on a Paramecium mutant blocked in the final step of the trichocyst extrusion process.

1980 ◽  
Vol 85 (2) ◽  
pp. 213-227 ◽  
Author(s):  
J Beisson ◽  
J Cohen ◽  
M Lefort-Tran ◽  
M Pouphile ◽  
M Rossignol
Keyword(s):  
Plasma Membrane ◽  
Membrane Fusion ◽  
Freeze Fracture ◽  
Acid Synthesis ◽  
Extrusion Process ◽  
Membrane Lipid ◽  
Effect Of Temperature ◽  
Physiological Studies ◽  
And Function ◽  
Induced Changes

Previous studies on exocytosis in Paramecium using mutants affecting trichocyst extrusion permitted us to analyze the assembly and function of three intramembrane particle arrays ("ring" and "rosette" in the plasma membrane, "annulus" in the trichocyst membrane) involved in the interaction between these two membranes. Using a conditional mutation, nd9, which blocks rosette assembly and prevents exocytosis at the nonpermissive temperature, we have analyzed the effect of temperature on the secretory capacity of nd9 cells. By combining several techniques (physiological studies, microinjections, inhibition of fatty acid synthesis, and freeze-fracture analysis) we demonstrate (a) that the product of the mutated allele nd9 is not thermolabile but that its activity is dependent upon temperature-induced changes in the membrane lipid composition and (b) that the product of the nd9 locus is a diffusible cytoplasmic component whose interaction with both plasma membrane and trichocyst membrane is required for rosette assembly and exocytosis. The data provide physiological evidence for the existence of a molecular complex(es) linking the two membranes and involved in the control of membrane fusion; we discuss the possible nature and function of these links.

Intramembrane particles distribution in the naturally synchronous stage of Physarum polycephalum

1992 ◽  
Vol 50 (1) ◽  
pp. 866-867
Author(s):  
Randolph Taylor ◽  
Henrie Turner
Keyword(s):  
Gene Expression ◽  
Gene Regulation ◽  
Plasma Membrane ◽  
Physarum Polycephalum ◽  
Freeze Fracture ◽  
Intramembrane Particles ◽  
Membrane Changes

Comparative ultrastructural investigations of the Physarum polycephalum intramembrane particles in the plasma membrane at different stages of the cycle has provided valuable information in relation to possible changes that occur in the plasma membrane of higher organisms. In addition, it gives insight on how plasma membrane changes correlate with gene expression and gene regulation in eukaryotes. In this report Freeze-fracture-etched techniques were utilized to study the arrangements of intramembrane particles (IMP) distribution and density at eight hours of the naturally synchronous plasmodial stage.

Organization of the boar spermatozoan plasma membrane: evidence for separate domains (subdomains) of integral membrane proteins in the plasma membrane overlying the principal segment of the acrosome

1987 ◽  
Vol 88 (3) ◽  
pp. 343-349
Author(s):  
R.N. Peterson ◽  
M. Gillott ◽  
W. Hunt ◽  
L.D. Russell
Keyword(s):  
Plasma Membrane ◽  
Membrane Proteins ◽  
Acrosome Reaction ◽  
Freeze Fracture ◽  
High Specificity ◽  
Sperm Head ◽  
Integral Membrane Proteins ◽  
Indirect Immunofluorescence Microscopy ◽  
Acrosomal Membrane ◽  
Acidic Phospholipids

Indirect immunofluorescence microscopy and freeze-fracture have been used to identify overlapping subdomains at the peripheral rim of the sperm-head plasma membrane (PM) and the margin of the outer acrosomal membrane (OAM) comprising the principal segment of the acrosome of the boar spermatozoon. An array of ridge-like structures (spaced 12–16 nm centre-to-centre), originally observed on the OAM by Aguas & Pinto da Silva, lies just beneath an area of the PM that is sparsely populated with large intramembranous particles compared to that of other regions of the head PM. This region has a high specificity for the lectin arachis hypogaea (peanut agglutinin). We suggest that the OAM at the rim of the sperm head may be rich in acidic phospholipids and that the close apposition of this membrane with a region of the PM relatively poor in integral membrane proteins may provide sites for initiating the acrosome reaction.

Freeze-fracture study of phagocytosis in Dictyostelium discoideum

1981 ◽  
Vol 51 (1) ◽  
pp. 63-84
Author(s):  
C. Favard-Sereno ◽  
M.A. Ludosky ◽  
A. Ryter
Keyword(s):  
Plasma Membrane ◽  
Dictyostelium Discoideum ◽  
Freeze Fracture ◽  
Thin Sections ◽  
Latex Beads ◽  
Fracture Study ◽  
Lateral Phase Separation ◽  
Membrane Changes ◽  
Freeze Fracture Electron Microscopy ◽  
Fracture Electron

The plasma membrane and its derivative, the phagosome membrane, were studied during and after ingestion of yeast of latex beads in Dictyostelium discoideum. Freeze-fracture electron microscopy, which provides information on the internal architecture of the membranes, and observation of thin sections of cells treated by cytochemical methods were used in parallel. For visualization of membrane sterols in the replicas, the cells were fixed in the presence of digitonin or the antibiotic filipin. No lateral phase separation occurred during yeast engulfment: the intramembranous particles (IMPs), phospholipids and sterols remained distributed at random in the forming phagosome membrane. In contrast architectural modifications of the membrane were observed upon phagosome internalization. Compared to the plasma membrane, the phagosome membrane displayed 2–3 times more IMPs a shift in the IMP size distribution and a higher sterol content. These changes were completed soon after phagosome closure; they were not related either to the nature of the ingested particles (yeast, latex beads) or to the pH in the membrane environment. The membrane changes too place when the phagosomes began to fuse with pre-existing digestive or autophagic vacuoles and lysosomes. Some of the experimental evidence suggests that the restructuring of the membrane may be related to the presence of hydrolases.

scholarly journals On the mechanism of rapid plasma membrane and chloroplast envelope expansion in Dunaliella salina exposed to hypoosmotic shock.

1986 ◽  
Vol 102 (1) ◽  
pp. 289-297 ◽  
Author(s):  
M Maeda ◽  
G A Thompson
Keyword(s):  
Plasma Membrane ◽  
Surface Area ◽  
Thin Section ◽  
Dunaliella Salina ◽  
Membrane Surface ◽  
Freeze Fracture ◽  
Chloroplast Envelope ◽  
Outer Envelope ◽  
High Concentration ◽  
Selective Fusion

Dunaliella salina cells rapidly diluted from their normal 1.71 M NaCl-containing growth medium into medium containing 0.86 M NaCl swelled within 2--4 min to an average volume 1.76 X larger and a surface area 1.53 X larger than found in control cells. Morphometric analysis of thin section electron micrographs revealed that certain organelles, including the chloroplast, nucleus, and some types of vacuoles, also expanded in surface area as much or more than did the entire cell. It is likely that glycerol, the most important osmotically active intracellular solute, was present in high concentration within these organelles as well as in the cytoplasm itself. Thin section and freeze-fracture electron microscopy were utilized to trace the origin of membrane material whose addition permitted the large increase in plasma membrane surface area and the equally large growth of the chloroplast outer envelope. The findings indicated that the plasma membrane's expansion resulted from its selective fusion with numerous small (less than or equal to 0.25 micron diam) vesicles prevalent throughout the cytoplasm. In contrast, new membrane added to the chloroplast outer envelope was drawn from an entirely different source, namely, elements of the endoplasmic reticulum.

Sign in / Sign up

Export Citation Format

Share Document