scholarly journals Intracellular Ion Changes Induced by the Exposure to Beta-Amyloid Can Be Explained by the Formation of Channels in the Lysosomal Membranes

2021 ◽  
Author(s):  
Dmitry V Zaretsky ◽  
Maria V Zaretskaia
Keyword(s):  
Plasma Membrane ◽  
High Resolution ◽  
Confocal Microscopy ◽  
Beta Amyloid ◽  
Living Cells ◽  
Channel Formation ◽  
Lysosomal Membranes ◽  
Induced Changes ◽  
Intracellular Ions ◽  
Channel Theory

In this manuscript, we reassess the data on beta-amyloid-induced changes of intracellular ions concentrations published previously by Abramov et al. (2003, 2004). Their observations made using high-resolution confocal microscopy with fast temporal resolution of images formed by fluorescent ion-sensitive fluorescent probes in living cells represent an unequivocal support for the amyloid channel theory. However, closer look reveals multiple facts which cannot be explained by channel formation in plasma membrane. Recently proposed amyloid degradation toxicity hypothesis provides the interpretation to these facts by considering that channels are formed in the lysosomal membranes.

Intracellular trafficking and cytoplasmic streaming under abiotic stress conditions

2019 ◽  
Vol 6 (04) ◽  
Author(s):  
JESHIMA KHAN YASIN ◽  
ANIL KUMAR SINGH
Keyword(s):  
Plasma Membrane ◽  
Abiotic Stress ◽  
Confocal Microscopy ◽  
Fusion Protein ◽  
Intracellular Trafficking ◽  
Cytoplasmic Streaming ◽  
Living Cells ◽  
Stress Conditions ◽  
Vesicle Formation ◽  
External Stimuli

Cytoplasmic streaming is one among the vital activities of the living cells. In plants cytolplasmic streaming could clearly be seen in hypocotyls of growing seedlings. To observe cytoplsmic streaming and its correlated intracellular trafficking an investigation was conducted in legumes in comparison with GFP-AtRab75 and 35S::GFP:δTIP tonoplast fusion protein expressing arabidopsis lines. These seedlings were observed under confocal microscopy with different buffer incubation treatments and under different stress conditions. GFP expressing 35S::GFP:δTIP tonoplast lines were looking similar to the control lines and differ under stress conditions. Movement of cytoplasmic invaginations within the tonoplast and cytoplasmic sub vesicle or bulb budding during cytoplasmic streaming was observed in hypocotyls of At-GFP tonoplast plants. We found the cytoplasmic bulbs/ vesicles or sub vesicle formation from the plasma membrane. The streaming speed also depends on the incubation medium in which the specimen was incubated, indicating that the external stimuli as well as internal stimuli can alter the speed of streaming

Microtubule Dynamics and Organelle Transport in Reticulomyxa

1990 ◽  
Vol 48 (3) ◽  
pp. 194-195
Author(s):  
Yih-Tai Chen ◽  
Ursula Euteneuer ◽  
Ken B. Johnson ◽  
Michael P. Koonce ◽  
Manfred Schliwa
Keyword(s):  
Plasma Membrane ◽  
Light Microscopy ◽  
Cytoplasmic Dynein ◽  
Living Cells ◽  
Microtubule Dynamics ◽  
Model Systems ◽  
Organelle Transport ◽  
Biochemical Characteristics ◽  
Dependent Transport

The application of video techniques to light microscopy and the development of motility assays in reactivated or reconstituted model systems rapidly advanced our understanding of the mechanism of organelle transport and microtubule dynamics in living cells. Two microtubule-based motors have been identified that are good candidates for motors that drive organelle transport: kinesin, a plus end-directed motor, and cytoplasmic dynein, which is minus end-directed. However, the evidence that they do in fact function as organelle motors is still indirect.We are studying microtubule-dependent transport and dynamics in the giant amoeba, Reticulomyxa. This cell extends filamentous strands backed by an extensive array of microtubules along which organelles move bidirectionally at up to 20 μm/sec (Fig. 1). Following removal of the plasma membrane with a mild detergent, organelle transport can be reactivated by the addition of ATP (1). The physiological, pharmacological and biochemical characteristics show the motor to be a cytoplasmic form of dynein (2).

Visualization of Membrane Sorting and Fusion in Living Cells using Total Internal Reflection (TIR) and Multicolor Video Microscopy

2001 ◽  
Vol 7 (S2) ◽  
pp. 34-35
Author(s):  
Derek Toomre ◽  
Patrick Keller ◽  
Elena Diaz ◽  
Jamie White ◽  
Kai Simons
Keyword(s):  
Plasma Membrane ◽  
Total Internal Reflection ◽  
Fluorescent Protein ◽  
Time Lapse ◽  
Living Cells ◽  
Video Microscopy ◽  
Internal Reflection ◽  
Fast Time ◽  
Cellular Polarity ◽  
Microscopy Technique

Post-Golgi sorting of different classes of newly synthesized proteins and lipids is central to the generation and maintenance of cellular polarity. to directly visualize the dynamics and location of apical/basolateral sorting and trafficking we used fast time-lapse multicolor video microscopy in living cells. Specifically, green fluorescent protein color variants (cyan, CFP; yellow, YFP) of apical cargo (GPI-anchored) and basolateral cargo (vesicular stomatitis virus glycoprotein, VSVG) were generated; see FIG 1. Fast dual color fluorescence video microscopy allowed visualization with high temporal and spatial resolution. Our studies revealed that apical and basolateral cargo progressively segregated into large domains in Golgi/TGN structures, excluded resident proteins, and exited in separate transport containers. These carries remained distinct and did not merge with endocytic structures en route to the plasma membrane. Interestingly, our data suggest that the primary sorting occurs by lateral segregation in the Golgi, prior to budding (FIG 2). Further characterization of morphological differences of apical versus basolateral transport carriers was achieved using a specialized microscopy technique called total internal reflection (TIR) microscopy. with this approach only the bottom of the cell (<100 nm) was illuminated by an exponentially decaying evanescent “wave” of light. A series of images, taken at ∼1 second intervals, shows a bright “flash” of fluorescence when the vesicle fuse with the plasma membrane and the fluorophore diffuses into the plasma membrane (FIG 3).

Imaging of Xenopus laevis Oocyte Plasma Membrane in Physiological-Like Conditions by Atomic Force Microscopy

2013 ◽  
Vol 19 (5) ◽  
pp. 1358-1363 ◽  
Author(s):  
Massimo Santacroce ◽  
Federica Daniele ◽  
Andrea Cremona ◽  
Diletta Scaccabarozzi ◽  
Michela Castagna ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Plasma Membrane ◽  
High Resolution ◽  
Membrane Proteins ◽  
Xenopus Laevis ◽  
Functional Study ◽  
Xenopus Laevis Oocyte ◽  
Force Microscopy ◽  
Atomic Force ◽  
Afm Imaging

AbstractXenopus laevis oocytes are an interesting model for the study of many developmental mechanisms because of their dimensions and the ease with which they can be manipulated. In addition, they are widely employed systems for the expression and functional study of heterologous proteins, which can be expressed with high efficiency on their plasma membrane. Here we applied atomic force microscopy (AFM) to the study of the plasma membrane of X. laevis oocytes. In particular, we developed and optimized a new sample preparation protocol, based on the purification of plasma membranes by ultracentrifugation on a sucrose gradient, to perform a high-resolution AFM imaging of X. laevis oocyte plasma membrane in physiological-like conditions. Reproducible AFM topographs allowed visualization and dimensional characterization of membrane patches, whose height corresponds to a single lipid bilayer, as well as the presence of nanometer structures embedded in the plasma membrane and identified as native membrane proteins. The described method appears to be an applicable tool for performing high-resolution AFM imaging of X. laevis oocyte plasma membrane in a physiological-like environment, thus opening promising perspectives for studying in situ cloned membrane proteins of relevant biomedical/pharmacological interest expressed in this biological system.

scholarly journals Localization of CD4 and CCR5 in Living Cells

2003 ◽  
Vol 77 (8) ◽  
pp. 4985-4991 ◽  
Author(s):  
Carolyn M. Steffens ◽  
Thomas J. Hope
Keyword(s):  
Human Immunodeficiency Virus ◽  
High Resolution ◽  
Cell Membrane ◽  
Cell Surface ◽  
Fluorescent Microscopy ◽  
Living Cells ◽  
Stable Complex ◽  
Membrane Structures ◽  
Virus Fusion ◽  
Immunodeficiency Virus

ABSTRACT The events preceding human immunodeficiency virus fusion and entry are influenced by the concentration and distribution of receptor and coreceptor molecules on the cell surface. However, the extent to which these proteins colocalize with one another in the cell membrane remains unclear. Using high-resolution deconvolution fluorescent microscopy of living cells, we found that both CD4 and CCR5 accumulate in protruding membrane structures containing actin and ezrin. Although CD4 and CCR5 extensively colocalize in these structures, they do not exist in a stable complex.

Sign in / Sign up

Export Citation Format

Share Document