scholarly journals Pre-embedding immunogold labeling to optimize protein localization at subcellular compartments and membrane microdomains of leukocytes

2014 ◽  
Vol 9 (10) ◽  
pp. 2382-2394 ◽  
Author(s):  
Rossana C N Melo ◽  
Ellen Morgan ◽  
Rita Monahan-Earley ◽  
Ann M Dvorak ◽  
Peter F Weller
Keyword(s):  
Protein Localization ◽  
Immunogold Labeling ◽  
Membrane Microdomains ◽  
Subcellular Compartments

scholarly journals Electron Microscopy Techniques for Investigating Structure and Composition of Hair-Cell Stereociliary Bundles

2021 ◽  
Vol 9 ◽  
Author(s):  
Maryna V. Ivanchenko ◽  
Artur A. Indzhykulian ◽  
David P. Corey
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Sample Preparation ◽  
Protein Localization ◽  
Imaging Techniques ◽  
Ion Beam ◽  
Immunogold Labeling ◽  
Sensory Cells ◽  
Optimal Sample ◽  
Scanning Electron

Hair cells—the sensory cells of the vertebrate inner ear—bear at their apical surfaces a bundle of actin-filled protrusions called stereocilia, which mediate the cells’ mechanosensitivity. Hereditary deafness is often associated with morphological disorganization of stereocilia bundles, with the absence or mislocalization within stereocilia of specific proteins. Thus, stereocilia bundles are closely examined to understand most animal models of hereditary hearing loss. Because stereocilia have a diameter less than a wavelength of light, light microscopy is not adequate to reveal subtle changes in morphology or protein localization. Instead, electron microscopy (EM) has proven essential for understanding stereocilia bundle development, maintenance, normal function, and dysfunction in disease. Here we review a set of EM imaging techniques commonly used to study stereocilia, including optimal sample preparation and best imaging practices. These include conventional and immunogold transmission electron microscopy (TEM) and scanning electron microscopy (SEM), as well as focused-ion-beam scanning electron microscopy (FIB-SEM), which enables 3-D serial reconstruction of resin-embedded biological structures at a resolution of a few nanometers. Parameters for optimal sample preparation, fixation, immunogold labeling, metal coating and imaging are discussed. Special attention is given to protein localization in stereocilia using immunogold labeling. Finally, we describe the advantages and limitations of these EM techniques and their suitability for different types of studies.

scholarly journals Organization of the Vesicular Stomatitis Virus Glycoprotein into Membrane Microdomains Occurs Independently of Intracellular Viral Components

2003 ◽  
Vol 77 (7) ◽  
pp. 3985-3992 ◽  
Author(s):  
Erica L. Brown ◽  
Douglas S. Lyles
Keyword(s):  
G Protein ◽  
Vesicular Stomatitis Virus ◽  
Plasma Membranes ◽  
Cytoplasmic Domain ◽  
Immunogold Labeling ◽  
Membrane Microdomains ◽  
Virus Budding ◽  
Infected Cells ◽  
Vesicular Stomatitis ◽  
Viral Components

ABSTRACT The glycoprotein (G protein) of vesicular stomatitis virus (VSV) is primarily organized in plasma membranes of infected cells into membrane microdomains with diameters of 100 to 150 nm, with smaller amounts organized into microdomains of larger sizes. This organization has been observed in areas of the infected-cell plasma membrane that are outside of virus budding sites as well as in the envelopes of budding virions. These observations raise the question of whether the intracellular virion components play a role in organizing the G protein into membrane microdomains. Immunogold-labeling electron microscopy was used to analyze the distribution of the G protein in arbitrarily chosen areas of plasma membranes of transfected cells that expressed the G protein in the absence of other viral components. Similar to the results with virus-infected cells, the G protein was organized predominantly into membrane microdomains with diameters of approximately 100 to 150 nm. These results indicate that internal virion components are not required to concentrate the G protein into membrane microdomains with a density similar to that of virus envelopes. To determine if interactions between the G protein cytoplasmic domain and internal virion components were required to create a virus budding site, cells infected with recombinant VSVs encoding truncation mutations of the G protein cytoplasmic domain were analyzed by immunogold-labeling electron microscopy. Deletion of the cytoplasmic domain of the G protein did not alter its partitioning into the 100- to 150-nm microdomains, nor did it affect the incorporation of the G protein into virus envelopes. These data support a model for virus assembly in which the G protein has the inherent property of partitioning into membrane microdomains that then serve as the sites of assembly of internal virion components.

Immunogold labeling of Pneumocystis carinii for Electron microscopy

1991 ◽  
Vol 49 ◽  
pp. 270-271
Author(s):  
Michael P. Goheen ◽  
Marilyn S. Bartlett ◽  
James W. Smith
Keyword(s):  
Electron Microscopy ◽  
Pneumocystis Carinii ◽  
Severe Pneumonia ◽  
Culture Fluid ◽  
Immunogold Labeling ◽  
Antigenic Sites ◽  
Transmission Electron ◽  
Response To Chemotherapy ◽  
Acquired Immunodeficiency ◽  
Immunodeficiency Syndrome

Studies of the biology of Pneumocystis carinii (PC) are of increasing importance because this extracellular pathogen is a frequent source of severe pneumonia in patients with acquired immunodeficiency syndrome (AIDS) and is a leading cause of mortality in these patients. Immunoelectron microscopic localization of antigenic sites on the surface of PC would improve the understanding of these sites and their role in pathenogenisis of the disease and response to chemotherapy. The purpose of this study was to develop a methodology for visualizing immunoreactive sites on PC with transmission electron microscopy (TEM) using immunogold labeled probes.Trophozoites of PC were added to spinner flask cultures and allowed to grow for 7 days, then aliquots of tissue culture fluid were centrifuged at 12,000 RPM for 30 sec. Pellets of organisims were fixed in either 1% glutaraldehyde, 0.1% glutaraldehyde-4% paraformaldehyde, or 4% paraformaldehyde for 4h. All fixatives were buffered with 0.1M Na cacodylate and the pH adjusted to 7.1. After fixation the pellets were rinsed in 0.1M Na cacodylate (3X), dehydrated with ethanol, and immersed in a 1:1 mixture of 95% ethanol and LR White resin.

Glucose metabolism in cancer cells: immunogold localization of hexokinase to the outer mitochondrial membrane

1995 ◽  
Vol 53 ◽  
pp. 1044-1045
Author(s):  
Krishan K. Arora ◽  
Glenn L. Decker ◽  
Peter L. Pedersen
Keyword(s):  
Tumor Cells ◽  
Mitochondrial Membrane ◽  
Present Report ◽  
Large Fraction ◽  
Mitochondrial Fraction ◽  
Immunogold Labeling ◽  
Outer Mitochondrial Membrane ◽  
Immunogold Localization ◽  
Hexokinase Activity ◽  
Normal Tissues

Hexokinase (ATP: D-hexose 6-phophotransferase EC 2.7.1.1) is the first enzyme of the glycolytic pathway which commits glucose to catabolism by catalyzing the phosphorylation of glucose with ATP. Previous studies have shown diat hexokinase activity is markedly elevated in rapidly growing tumor cells exhibiting high glucose catabolic rates. A large fraction (50-80%) of this enzyme activity is bound to the mitochondrial fraction (1,2) where it has preferred access to ATP (3). In contrast,the hexokinase activity of normal tissues is quite low, with one exception being brain which is a glucose-utilizing tissue (4). Biochemical evidence involving rigorous subfractionation studies have revealed striking differences between the subcellular distribution of hexokinase in normal and tumor cells [See review by Arora et al (4)].In the present report, we have utilized immunogold labeling techniques to evaluate die subcellular localization of hexokinase in highly glycolytic AS-30D hepatoma cells and in the tissue of its origin, i.e., rat liver.

Segregation of cell adhesion molecules into membrane microdomains facilitates leukocyte-endothelial interactions

1995 ◽  
Vol 53 ◽  
pp. 780-781
Author(s):  
S.L. Erlandsen
Keyword(s):  
Cell Surface ◽  
Adhesion Molecules ◽  
Colloidal Gold ◽  
High Spatial Resolution ◽  
Low Voltage ◽  
Cellular Adhesion ◽  
Membrane Microdomains ◽  
Immunogold Label ◽  
Cellular Adhesion Molecules ◽  
Electron Detection

Cells interact with their extracellular environments by means of a variety of cellular adhesion molecules (CAM) and surface ligands. In many instances, CAMs interact in a sequential temporal fashion which suggests that these adhesion molecules may occupy or be polarized to various membrane microdomains on the cell surface. Detection of CAMs can be accomplished by a variety of methods including immunofluorescent microscopy and flow cytometry, and by the use of immunocytochemical markers (i.e. colloidal gold) in electron microscopy. The development of high resolution field emission SEM in the mid 1980's and the Autrata modification of the YAG detector for backscatter electron detection at low voltage has greatly facilitated the recognition of colloidal gold probes for detection of surface CAMs. Low voltage FESEM with Bse imaging provides increased resolution of cell surface topography (~3nm at 3-4 keV) which can be observed in 3-dimensions, and simultaneously permits detection/high spatial resolution of immunogold label by atomic number contrast.

Membrane microdomains: lessons from microscopy

1995 ◽  
Vol 53 ◽  
pp. 776-777
Author(s):  
J.M. Robinson ◽  
J.M Oliver
Keyword(s):  
Spatial Distribution ◽  
Plasma Membrane ◽  
Epithelial Cells ◽  
Plasma Membranes ◽  
Cell Types ◽  
Imaging Modalities ◽  
Membrane Microdomains ◽  
Membrane Domains ◽  
Lateral Heterogeneity ◽  
Functional Importance

Specialized regions of plasma membranes displaying lateral heterogeneity are the focus of this Symposium. Specialized membrane domains are known for certain cell types such as differentiated epithelial cells where lateral heterogeneity in lipids and proteins exists between the apical and basolateral portions of the plasma membrane. Lateral heterogeneity and the presence of microdomains in membranes that are uniform in appearance have been more difficult to establish. Nonetheless a number of studies have provided evidence for membrane microdomains and indicated a functional importance for these structures.This symposium will focus on the use of various imaging modalities and related approaches to define membrane microdomains in a number of cell types. The importance of existing as well as emerging imaging technologies for use in the elucidation of membrane microdomains will be highlighted. The organization of membrane microdomains in terms of dimensions and spatial distribution is of considerable interest and will be addressed in this Symposium.

Quantification of gold labeled cell surface antigens by SEM: Current progress and remaining problems

1990 ◽  
Vol 48 (3) ◽  
pp. 34-35
Author(s):  
Etienne de Harven ◽  
Davide Soligo ◽  
Roy McGroarty ◽  
Hilary Christensen ◽  
Richard Leung ◽  
...  
Keyword(s):  
Cell Surface ◽  
Immunogold Labeling ◽  
Target Antigen ◽  
Facs Analysis ◽  
Becton Dickinson ◽  
Cell Surface Antigens ◽  
Human T Lymphocyte ◽  
Backscattered Electron ◽  
Imaging Mode ◽  
Electron Imaging

Taking advantage of the high elemental contrast of particles of colloidal gold observed in the backscattered electron imaging(BEI) mode of the SEM (1,2), the human T lymphocyte was chosen as a model system to study the potential value of immunogold labeling for the quantification of cell surface expressed molecules. The CD3 antigen which is expressed on all human T lymphocytes and is readily identified by the LEU-4 murine monoclonal antibody (Becton Dickinson, Mountain View, CA) followed by a gold conjugated goat anti-mouse Ig polyclonal antibody was chosen as a model target antigen. When quantified by non-EM methods, using radio-iodinated probes or FACS analysis, approximately 30,000 to 50,000 copies of this antigen per cell are enumerated.The following observations were made while attempting to quantify the same molecule by SEM after specific immunogold labeling:Imaging in the SE vs BE mode: The numbers of gold markers counted in the secondary electron (SE) imaging mode are considerably lower than those counted on the same cells in the backscattered electron (BE) imaging mode.

Lighting a path: genetic studies pinpoint neurodevelopmental mechanisms in autism and related disorders

2012 ◽  
Vol 14 (3) ◽  
pp. 239-252
Keyword(s):  
Molecular Mechanisms ◽  
Protein Localization ◽  
Regulation Of Gene Expression ◽  
Neuronal Cell ◽  
Mrna Splicing ◽  
Genetic Mutations ◽  
Scaffolding Proteins ◽  
Molecular Processes ◽  
Genetic Studies ◽  
Novel Treatments

In this review, we outline critical molecular processes that have been implicated by discovery of genetic mutations in autism. These mechanisms need to be mapped onto the neurodevelopment step(s) gone awry that may be associated with cause in autism. Molecular mechanisms include: (i) regulation of gene expression; (ii) pre-mRNA splicing; (iii) protein localization, translation, and turnover; (iv) synaptic transmission; (v) cell signaling; (vi) the functions of cytoskeletal and scaffolding proteins; and (vii) the function of neuronal cell adhesion molecules. While the molecular mechanisms appear broad, they may converge on only one of a few steps during neurodevelopment that perturbs the structure, function, and/or plasticity of neuronal circuitry. While there are many genetic mutations involved, novel treatments may need to target only one of few developmental mechanisms.

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