scholarly journals A new probe for super-resolution imaging of membranes elucidates trafficking pathways

2014 ◽  
Vol 205 (4) ◽  
pp. 591-606 ◽  
Author(s):  
Natalia H. Revelo ◽  
Dirk Kamin ◽  
Sven Truckenbrodt ◽  
Aaron B. Wong ◽  
Kirsten Reuter-Jessen ◽  
...  
Keyword(s):  
Synaptic Vesicles ◽  
Cultured Cells ◽  
Neuromuscular Junctions ◽  
Organ Of Corti ◽  
Super Resolution ◽  
Molecular Composition ◽  
Cultured Neurons ◽  
Vesicle Recycling ◽  
Resolution Imaging ◽  
Super Resolution Microscopy

The molecular composition of the organelles involved in membrane recycling is difficult to establish as a result of the absence of suitable labeling tools. We introduce in this paper a novel probe, named membrane-binding fluorophore-cysteine-lysine-palmitoyl group (mCLING), which labels the plasma membrane and is taken up during endocytosis. It remains attached to membranes after fixation and permeabilization and can therefore be used in combination with immunostaining and super-resolution microscopy. We applied mCLING to mammalian-cultured cells, yeast, bacteria, primary cultured neurons, Drosophila melanogaster larval neuromuscular junctions, and mammalian tissue. mCLING enabled us to study the molecular composition of different trafficking organelles. We used it to address several questions related to synaptic vesicle recycling in the auditory inner hair cells from the organ of Corti and to investigate molecular differences between synaptic vesicles that recycle actively or spontaneously in cultured neurons. We conclude that mCLING enables the investigation of trafficking membranes in a broad range of preparations.

Tools and limitations to study the molecular composition of synapses by fluorescence microscopy

2016 ◽  
Vol 473 (20) ◽  
pp. 3385-3399 ◽  
Author(s):  
Manuel Maidorn ◽  
Silvio O. Rizzoli ◽  
Felipe Opazo
Keyword(s):  
Super Resolution ◽  
Molecular Composition ◽  
Synaptic Organization ◽  
Synaptic Physiology ◽  
Copy Numbers ◽  
Resolution Imaging ◽  
And Function ◽  
Microscopy Techniques ◽  
Super Resolution Microscopy ◽  
Affinity Probes

The synapse is densely packed with proteins involved in various highly regulated processes. Synaptic protein copy numbers and their stoichiometric distribution have a drastic influence on neuronal integrity and function. Therefore, the molecular analysis of synapses is a key element to understand their architecture and function. The overall structure of the synapse has been revealed with an exquisite amount of details by electron microscopy. However, the molecular composition and the localization of proteins are more easily addressed with fluorescence imaging, especially with the improved resolution achieved by super-resolution microscopy techniques. Notably, the fast improvement of imaging instruments has not been reflected in the optimization of biological sample preparation. During recent years, large efforts have been made to generate affinity probes smaller than conventional antibodies adapted for fluorescent super-resolution imaging. In this review, we briefly discuss the current views on synaptic organization and necessary key technologies to progress in the understanding of synaptic physiology. We also highlight the challenges faced by current fluorescent super-resolution methods, and we describe the prerequisites for an ideal study of synaptic organization.

scholarly journals Nanoscale dynamics of synaptic vesicle trafficking and fusion at the presynaptic active zone

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Thirumalini Vaithianathan ◽  
Diane Henry ◽  
Wendy Akmentin ◽  
Gary Matthews
Keyword(s):  
Active Zone ◽  
Synaptic Vesicles ◽  
Super Resolution ◽  
Visual Signals ◽  
Dual Function ◽  
Macromolecular Complex ◽  
Synaptic Ribbon ◽  
Modes Of Transmission ◽  
Resolution Imaging ◽  
Specialized Structure

The cytomatrix at the active zone (CAZ) is a macromolecular complex that facilitates the supply of release-ready synaptic vesicles to support neurotransmitter release at synapses. To reveal the dynamics of this supply process in living synapses, we used super-resolution imaging to track single vesicles at voltage-clamped presynaptic terminals of retinal bipolar neurons, whose CAZ contains a specialized structure—the synaptic ribbon—that supports both fast, transient and slow, sustained modes of transmission. We find that the synaptic ribbon serves a dual function as a conduit for diffusion of synaptic vesicles and a platform for vesicles to fuse distal to the plasma membrane itself, via compound fusion. The combination of these functions allows the ribbon-type CAZ to achieve the continuous transmitter release required by synapses of neurons that carry tonic, graded visual signals in the retina.

scholarly journals Super-resolution microscopy can identify specific protein distribution patterns in platelets incubated with cancer cells

Nanoscale ◽  
2019 ◽  
Vol 11 (20) ◽  
pp. 10023-10033 ◽  
Author(s):  
Jan Bergstrand ◽  
Lei Xu ◽  
Xinyan Miao ◽  
Nailin Li ◽  
Ozan Öktem ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Dictionary Learning ◽  
Super Resolution ◽  
Distribution Patterns ◽  
Specific Protein ◽  
Protein Distribution ◽  
Activated Platelets ◽  
Resolution Imaging ◽  
Super Resolution Microscopy

Super-resolution imaging of P-selectin in platelets together with dictionary learning allow specifically activated platelets to be identified in an automatic objective manner.

scholarly journals Super-Resolution Microscopy of Chromatin

Genes ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 493 ◽  
Author(s):  
Birk
Keyword(s):  
Gene Regulation ◽  
Data Analysis ◽  
Super Resolution ◽  
Fluorescence Labeling ◽  
Cellular Processes ◽  
Direct Assessment ◽  
Chromatin Interactions ◽  
Resolution Imaging ◽  
Super Resolution Microscopy ◽  
Insight Into

Since the advent of super-resolution microscopy, countless approaches and studies have been published contributing significantly to our understanding of cellular processes. With the aid of chromatin-specific fluorescence labeling techniques, we are gaining increasing insight into gene regulation and chromatin organization. Combined with super-resolution imaging and data analysis, these labeling techniques enable direct assessment not only of chromatin interactions but also of the function of specific chromatin conformational states.

scholarly journals Bioorthogonal double-fluorogenic siliconrhodamine probes for intracellular super-resolution microscopy

2017 ◽  
Vol 53 (50) ◽  
pp. 6696-6699 ◽  
Author(s):  
E. Kozma ◽  
G. Estrada Girona ◽  
G. Paci ◽  
E. A. Lemke ◽  
P. Kele
Keyword(s):  
Super Resolution ◽  
Site Specific ◽  
Intracellular Proteins ◽  
Resolution Imaging ◽  
Super Resolution Microscopy

A series of double-fluorogenic siliconrhodamine-tetrazines were synthesized. One of these tetrazines is a membrane-permeant label allowing site-specific bioorthogonal tagging of intracellular proteins and super-resolution imaging.

scholarly journals Focus on Super-Resolution Imaging with Direct Stochastic Optical Reconstruction Microscopy (dSTORM)

2014 ◽  
Vol 67 (2) ◽  
pp. 179 ◽  
Author(s):  
Donna R. Whelan ◽  
Thorge Holm ◽  
Markus Sauer ◽  
Toby D. M. Bell
Keyword(s):  
Cell Biology ◽  
Super Resolution ◽  
Diffraction Limit ◽  
Stochastic Optical Reconstruction Microscopy ◽  
Resolution Imaging ◽  
Optical Reconstruction ◽  
Set Up ◽  
Microscopy Techniques ◽  
Super Resolution Microscopy ◽  
Microscopic Techniques

The last decade has seen the development of several microscopic techniques capable of achieving spatial resolutions that are well below the diffraction limit of light. These techniques, collectively referred to as ‘super-resolution’ microscopy, are now finding wide use, particularly in cell biology, routinely generating fluorescence images with resolutions in the order of tens of nanometres. In this highlight, we focus on direct Stochastic Optical Reconstruction Microscopy or dSTORM, one of the localisation super-resolution fluorescence microscopy techniques that are founded on the detection of fluorescence emissions from single molecules. We detail how, with minimal assemblage, a highly functional and versatile dSTORM set-up can be built from ‘off-the-shelf’ components at quite a modest budget, especially when compared with the current cost of commercial systems. We also present some typical super-resolution images of microtubules and actin filaments within cells and discuss sample preparation and labelling methods.

scholarly journals Molecular resolution imaging by post-labeling expansion single-molecule localization microscopy (Ex-SMLM)

2020 ◽  
Author(s):  
Fabian U. Zwettler ◽  
Sebastian Reinhard ◽  
Davide Gambarotto ◽  
Toby D. M. Bell ◽  
Virginie Hamel ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Single Molecule ◽  
Super Resolution ◽  
Reference Structure ◽  
Positional Error ◽  
Localization Microscopy ◽  
Resolution Imaging ◽  
Endogenous Proteins ◽  
Super Resolution Microscopy ◽  
Single Molecule Localization Microscopy

AbstractExpansion microscopy (ExM) enables super-resolution fluorescence imaging of physically expanded biological samples with conventional microscopes. By combining expansion microscopy (ExM) with single-molecule localization microscopy (SMLM) it is potentially possible to approach the resolution of electron microscopy. However, current attempts to combine both methods remained challenging because of protein and fluorophore loss during digestion or denaturation, gelation, and the incompatibility of expanded polyelectrolyte hydrogels with photoswitching buffers. Here we show that re-embedding of expanded hydrogels enables dSTORM imaging of expanded samples and demonstrate that post-labeling ExM resolves the current limitations of super-resolution microscopy. Using microtubules as a reference structure and centrioles, we demonstrate that post-labeling Ex-SMLM preserves ultrastructural details, improves the labeling efficiency and reduces the positional error arising from linking fluorophores into the gel thus paving the way for super-resolution imaging of immunolabeled endogenous proteins with true molecular resolution.

scholarly journals Genetically encoded photo-switchable molecular sensors for optoacoustic and super-resolution imaging

2021 ◽  
Author(s):  
Kanuj Mishra ◽  
Juan Pablo Fuenzalida-Werner ◽  
Francesca Pennacchietti ◽  
Robert Janowski ◽  
Andriy Chmyrov ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Fluorescent Protein ◽  
Cultured Cells ◽  
Super Resolution ◽  
Structural Level ◽  
Optoacoustic Imaging ◽  
Molecular Sensors ◽  
The Core ◽  
Resolution Imaging ◽  
G Protein Coupled

AbstractReversibly photo-switchable proteins are essential for many super-resolution fluorescence microscopic and optoacoustic imaging methods. However, they have yet to be used as sensors that measure the distribution of specific analytes at the nanoscale or in the tissues of live animals. Here we constructed the prototype of a photo-switchable Ca2+ sensor based on GCaMP5G that can be switched with 405/488-nm light and describe its molecular mechanisms at the structural level, including the importance of the interaction of the core barrel structure of the fluorescent protein with the Ca2+ receptor moiety. We demonstrate super-resolution imaging of Ca2+ concentration in cultured cells and optoacoustic Ca2+ imaging in implanted tumor cells in mice under controlled Ca2+ conditions. Finally, we show the generalizability of the concept by constructing examples of photo-switching maltose and dopamine sensors based on periplasmatic binding protein and G-protein-coupled receptor-based sensors.

scholarly journals Ultrafast endocytosis at Caenorhabditis elegans neuromuscular junctions

eLife ◽  
2013 ◽  
Vol 2 ◽  
Author(s):  
Shigeki Watanabe ◽  
Qiang Liu ◽  
M Wayne Davis ◽  
Gunther Hollopeter ◽  
Nikita Thomas ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Motor Neurons ◽  
Synaptic Vesicles ◽  
Neuromuscular Junctions ◽  
Light Stimulus ◽  
Single Stimulus ◽  
Vesicle Recycling ◽  
Ultrastructural Studies ◽  
Millisecond Time Scale ◽  
Intense Stimulation

Synaptic vesicles can be released at extremely high rates, which places an extraordinary demand on the recycling machinery. Previous ultrastructural studies of vesicle recycling were conducted in dissected preparations using an intense stimulation to maximize the probability of release. Here, a single light stimulus was applied to motor neurons in intact Caenorhabditis elegans nematodes expressing channelrhodopsin, and the animals rapidly frozen. We found that docked vesicles fuse along a broad active zone in response to a single stimulus, and are replenished with a time constant of about 2 s. Endocytosis occurs within 50 ms adjacent to the dense projection and after 1 s adjacent to adherens junctions. These studies suggest that synaptic vesicle endocytosis may occur on a millisecond time scale following a single physiological stimulus in the intact nervous system and is unlikely to conform to current models of endocytosis.

scholarly journals Bioorthogonal labeling of transmembrane proteins with non-canonical amino acids allows access to masked epitopes in live neurons

2021 ◽  
Author(s):  
Diogo Bessa-Neto ◽  
Alexander Kuhlemann ◽  
Gerti Beliu ◽  
Valeria Pecoraro ◽  
Sören Doose ◽  
...  
Keyword(s):  
Amino Acids ◽  
Brain Slices ◽  
Transmembrane Proteins ◽  
Super Resolution ◽  
Biological Imaging ◽  
Bioorthogonal Labeling ◽  
Resolution Imaging ◽  
Genetic Code Expansion ◽  
Super Resolution Microscopy ◽  
Organotypic Brain Slices

ABSTRACTProgress in biological imaging is intrinsically linked to advances in labeling methods. The explosion in the development of high-resolution and super-resolution imaging calls for new approaches to label targets with small probes. These should allow to faithfully report the localization of the target within the imaging resolution – typically nowadays a few nanometers - and allow access to any epitope of the target, in the native cellular and tissue environment. We report here the development of a complete labeling and imaging pipeline using genetic code expansion and non-canonical amino acids in primary neurons that allows to fluorescently label masked epitopes in target transmembrane proteins in live neurons, both in dissociated culture and organotypic brain slices. This allowed us to image the differential localization of two glutamate receptor auxiliary proteins in complex with their partner with a variety of methods including widefield, confocal, and dSTORM super-resolution microscopy.

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