scholarly journals Minimal genetically encoded tags for fluorescent protein labeling in living neurons

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Aleksandra Arsić ◽  
Cathleen Hagemann ◽  
Nevena Stajković ◽  
Timm Schubert ◽  
Ivana Nikić-Spiegel
Keyword(s):  
Unnatural Amino Acids ◽  
Genome Engineering ◽  
Fluorescent Protein ◽  
Super Resolution ◽  
Neurofilament Light Chain ◽  
Neurofilament Light ◽  
Fixed Cell ◽  
Living Neurons ◽  
Microscopy Techniques ◽  
Super Resolution Microscopy

AbstractModern light microscopy, including super-resolution techniques, has brought about a demand for small labeling tags that bring the fluorophore closer to the target. This challenge can be addressed by labeling unnatural amino acids (UAAs) with bioorthogonal click chemistry. The minimal size of the UAA and the possibility to couple the fluorophores directly to the protein of interest with single-residue precision in living cells make click labeling unique. Here, we establish click labeling in living primary neurons and use it for fixed-cell, live-cell, dual-color pulse–chase, and super-resolution microscopy of neurofilament light chain (NFL). We also show that click labeling can be combined with CRISPR/Cas9 genome engineering for tagging endogenous NFL. Due to its versatile nature and compatibility with advanced multicolor microscopy techniques, we anticipate that click labeling will contribute to novel discoveries in the neurobiology field.

scholarly journals Minimal genetically encoded tags for fluorescent protein labeling in living neurons

2021 ◽  
Author(s):  
Aleksandra Arsić ◽  
Cathleen Hagemann ◽  
Nevena Stajković ◽  
Timm Schubert ◽  
Ivana Nikić-Spiegel
Keyword(s):  
Click Chemistry ◽  
Unnatural Amino Acids ◽  
Genome Engineering ◽  
Fluorescent Protein ◽  
Super Resolution ◽  
Live Cell ◽  
Cell Labeling ◽  
Neurofilament Light Chain ◽  
Neurofilament Light ◽  
Fixed Cell

AbstractModern light microscopy, including super-resolution techniques, brought about a demand for small labeling tags that bring the fluorophore closer to the target. This challenge can be addressed by labeling unnatural amino acids (UAAs) with click chemistry. UAAs are site-specifically incorporated into a protein of interest by genetic code expansion. If the UAA carries a strained alkene or alkyne moiety it can be conjugated to a tetrazine-bearing fluorophore via a strain-promoted inverse-electron-demand Diels–Alder cycloaddition (SPIEDAC), a variant of bioorthogonal click chemistry. The minimal size of the incorporated tag and the possibility to couple the fluorophores directly to the protein of interest with single-residue precision make SPIEDAC live-cell labeling unique. However, until now, this type of labeling has not been used in complex, non-dividing cells, such as neurons. Using neurofilament light chain as a target protein, we established SPIEDAC labeling in living primary neurons and applied it for fixed-cell, live-cell, dual-color pulse—chase and super-resolution microscopy. We also show that SPIEDAC labeling can be combined with CRISPR/Cas9 genome engineering for tagging endogenous NFL. Due to its versatile nature and compatibility with advanced microscopy techniques, we anticipate that SPIEDAC labeling will contribute to novel discoveries in neurobiology.

Structural Evidence of Photoisomerization Pathways in Fluorescent Proteins

2019 ◽  
Author(s):  
Jeffrey Chang ◽  
Matthew Romei ◽  
Steven Boxer
Keyword(s):  
Rational Design ◽  
Fluorescent Protein ◽  
Fluorescent Proteins ◽  
Super Resolution ◽  
Unit Cell Size ◽  
Chlorine Substituent ◽  
Gfp Chromophore ◽  
The One ◽  
Green Fluorescent ◽  
Super Resolution Microscopy

<p>Double-bond photoisomerization in molecules such as the green fluorescent protein (GFP) chromophore can occur either via a volume-demanding one-bond-flip pathway or via a volume-conserving hula-twist pathway. Understanding the factors that determine the pathway of photoisomerization would inform the rational design of photoswitchable GFPs as improved tools for super-resolution microscopy. In this communication, we reveal the photoisomerization pathway of a photoswitchable GFP, rsEGFP2, by solving crystal structures of <i>cis</i> and <i>trans</i> rsEGFP2 containing a monochlorinated chromophore. The position of the chlorine substituent in the <i>trans</i> state breaks the symmetry of the phenolate ring of the chromophore and allows us to distinguish the two pathways. Surprisingly, we find that the pathway depends on the arrangement of protein monomers within the crystal lattice: in a looser packing, the one-bond-flip occurs, whereas in a tighter packing (7% smaller unit cell size), the hula-twist occurs.</p><p> </p><p> </p><p> </p><p> </p><p> </p><p> </p> <p> </p>

scholarly journals Storm-Lite: An Inexpensive Tool to Demonstrate Stochastic Super Resolution Microscopy Techniques in the Classroom

2017 ◽  
Vol 112 (3) ◽  
pp. 464a
Author(s):  
Anthony Wu ◽  
Lark Moreno ◽  
Maxim Prigozhin ◽  
Sharlene Denos
Keyword(s):  
Super Resolution ◽  
Microscopy Techniques ◽  
Super Resolution Microscopy

scholarly journals How did correlative atomic force microscopy and super-resolution microscopy evolve in the quest for unravelling enigmas in biology?

Nanoscale ◽  
2021 ◽  
Author(s):  
Adelaide Miranda ◽  
Ana I. Gómez-Varela ◽  
Andreas Stylianou ◽  
Liisa M. Hirvonen ◽  
Humberto Sánchez ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Super Resolution ◽  
Force Microscopy ◽  
Atomic Force ◽  
Microscopy Techniques ◽  
Super Resolution Microscopy ◽  
Detailed Picture

This review provides a detailed picture of the innovative efforts to combine atomic force microscopy and different super-resolution microscopy techniques to elucidate biological questions.

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.

Expression-Enhanced Fluorescent Proteins Based on Enhanced Green Fluorescent Protein for Super-resolution Microscopy

ACS Nano ◽  
2015 ◽  
Vol 9 (10) ◽  
pp. 9528-9541 ◽  
Author(s):  
Sam Duwé ◽  
Elke De Zitter ◽  
Vincent Gielen ◽  
Benjamien Moeyaert ◽  
Wim Vandenberg ◽  
...  
Keyword(s):  
Green Fluorescent Protein ◽  
Enhanced Green Fluorescent Protein ◽  
Fluorescent Protein ◽  
Fluorescent Proteins ◽  
Super Resolution ◽  
Green Fluorescent ◽  
Super Resolution Microscopy

scholarly journals Nanoscopic dopamine transporter distribution and conformation are inversely regulated by excitatory drive and D2-autoreceptor activity

2021 ◽  
Author(s):  
Matthew D. Lycas ◽  
Aske L. Ejdrup ◽  
Andreas T. Sørensen ◽  
Nicolai O. Haahr ◽  
Søren H. Jørgensen ◽  
...  
Keyword(s):  
Dopamine Transporter ◽  
Single Molecule ◽  
Dynamic Equilibrium ◽  
Super Resolution ◽  
Striatal Slices ◽  
D2 Autoreceptor ◽  
Molecular Components ◽  
Microscopy Techniques ◽  
Super Resolution Microscopy ◽  
Excitatory Drive

SUMMARYThe nanoscopic organization and regulation of individual molecular components in presynaptic varicosities of neurons releasing modulatory volume neurotransmitters like dopamine (DA) remain largely elusive. Here we show by application of several single-molecule sensitive super-resolution microscopy techniques to cultured neurons and mouse striatal slices, that the dopamine transporter (DAT), a key protein in varicosities of dopaminergic neurons, exists in the membrane in dynamic equilibrium between an inward-facing nanodomain-localized and outward-facing unclustered configuration. The balance between these configurations is inversely regulated by excitatory drive and by DA D2-autoreceptor activation in manner dependent on Ca2+-influx via N-type voltage-gated Ca2+-channels. The DAT nanodomains contain tens of transporters molecules and overlap with nanodomains of PIP2 (phosphatidylinositol-4,5-bisphosphate) but show little overlap with D2-autoreceptor, syntaxin-1 and clathrin nanodomains. By demonstrating that nanoscopic reorganizations with putative major impact on transmitter homeostasis can take place in dopaminergic varicosities, the data have important implications for understanding modulatory neurotransmitter physiology.

scholarly journals Dynamics and nanoscale organization of the postsynaptic endocytic zone at excitatory synapses

2021 ◽  
Author(s):  
Lisa A.E. Catsburg ◽  
Manon Westra ◽  
Annemarie M. L. van Schaik ◽  
Harold D. MacGillavry
Keyword(s):  
Synaptic Plasticity ◽  
Actin Cytoskeleton ◽  
Glutamate Receptors ◽  
Super Resolution ◽  
Live Cell ◽  
Excitatory Synapses ◽  
Membrane Interactions ◽  
Synaptic Receptors ◽  
Microscopy Techniques ◽  
Super Resolution Microscopy

ABSTRACTAt postsynaptic sites of neurons, a prominent clathrin-coated structure, the endocytic zone (EZ), controls the trafficking of glutamate receptors and is essential for synaptic plasticity. Despite its importance, little is known about how this clathrin structure is organized to mediate endocytosis. We used live-cell and super-resolution microscopy techniques to reveal the dynamic organization of this poorly understood clathrin structure. We found that a subset of endocytic proteins only transiently appeared at postsynaptic sites. In contrast, other proteins, including Eps15, intersectin1L, and β2-adaptin, were persistently enriched and partitioned at the edge of the EZ. We found that uncoupling the EZ from the synapse led to the loss of most of these components, while disrupting the actin cytoskeleton or AP2-membrane interactions did not alter EZ positioning. We conclude that the EZ is a stable, highly organized molecular platform where components are differentially recruited and positioned to orchestrate the endocytosis of synaptic receptors.

scholarly journals Microscope-AOtools: A generalised adaptive optics implementation

2020 ◽  
Author(s):  
Nicholas Hall ◽  
Josh Titlow ◽  
Martin J. Booth ◽  
Ian M. Dobbie
Keyword(s):  
Image Quality ◽  
Adaptive Optics ◽  
Super Resolution ◽  
Biological Imaging ◽  
New Techniques ◽  
Reduce Image Quality ◽  
Set Up ◽  
And Function ◽  
Microscopy Techniques ◽  
Super Resolution Microscopy

AbstractMicroscope-AOtools is a software package which allows for a simple, robust and generalised implementation of adaptive optics (AO) elements. It contains all the necessary methods for set-up, calibration, and aberration correction which are simple to use and function in a robust manner. Aberrations arising from sources such as sample hetero-geneity and refractive index mismatches are constant problems in biological imaging. These aberrations reduce image quality and the achievable depth of imaging, particularly in super-resolution microscopy techniques. AO technology has been proven to be effective in correcting for these aberrations and thereby improving the image quality. However, it has not been widely adopted by the biological imaging community due, in part, to difficulty in set-up and operation of AO, particularly by non-specialist users. Microscope-AOtools offers a robust, easy-to-use implementation of the essential methods for set-up and use of AO techniques. These methods are constructed in a generalised manner that can utilise a range of adaptive optics elements, wavefront sensing techniques and sensorless AO correction methods. Furthermore, the methods are designed to be easily extensible as new techniques arise, leading to a streamlined pipeline for new AO technology and techniques to be adopted by the wider microscopy community.

scholarly journals Embracing the uncertainty: the evolution of SOFI into a diverse family of fluctuation-based super-resolution microscopy methods

2021 ◽  
Author(s):  
Monika Pawlowska ◽  
Ron Tenne ◽  
Bohnishikha Ghosh ◽  
Adrian Makowski ◽  
Radek Lapkiewicz
Keyword(s):  
3D Imaging ◽  
Deep Neural Networks ◽  
Fluorescent Proteins ◽  
Super Resolution ◽  
Significant Progress ◽  
Spatial Correlations ◽  
Order Of Magnitude ◽  
Temporal And Spatial ◽  
Microscopy Techniques ◽  
Super Resolution Microscopy

Abstract Super-resolution microscopy techniques have pushed the limits of resolution in optical imaging by more than an order of magnitude. However, these methods often require long acquisition times as well as complex setups and sample preparation protocols. Super-resolution Optical Fluctuation Imaging (SOFI) emerged over ten years ago as an approach that exploits temporal and spatial correlations within the acquired images to obtain increased resolution with less strict requirements. This review follows the progress of SOFI from its first demonstration to the development of a branch of methods that treat fluctuations as a source of contrast, rather than noise. Among others, we highlight the implementation of SOFI with standard fluorescent proteins as well as the microscope modification that facilitate 3D imaging and the application of modern cameras. Going beyond the classical framework of SOFI, we explore different innovative concepts from deep neural networks all the way to a quantum analogue of SOFI, antibunching microscopy. While SOFI has not reached the same level of ubiquity as other super-resolution methods, our overview finds significant progress and substantial potential for the concept of leveraging fluorescence fluctuations to obtain super-resolved images.

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