scholarly journals A simple and efficient CRISPR technique for protein tagging

2019 ◽  
Author(s):  
Fanning Zeng ◽  
Valerie Beck ◽  
Sven Schuierer ◽  
Isabelle Garnier ◽  
Carole Manneville ◽  
...  
Keyword(s):  
Live Cell Imaging ◽  
Cell Imaging ◽  
Fluorescent Protein ◽  
Cell Types ◽  
Luciferase Assay ◽  
Primary Cells ◽  
Transfected Cells ◽  
Homology Directed Repair ◽  
Protein Tagging ◽  
Selection Of

Genetic knock-in using homology directed repair is an inefficient process, requiring selection of few modified cells and hindering its application to primary cells. Here we describeHomologyindependent geneTagging (HiTag), a method to tag a protein of interest by CRISPR in up to 66% transfected cells with one single electroporation. The technique has proven effective in various cell types, can be used to knock in a fluorescent protein for live cell imaging, to modify the cellular location of a target protein and to monitor levels of a protein of interest by a luciferase assay in primary cells.

scholarly journals A Simple and Efficient CRISPR Technique for Protein Tagging

Cells ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2618
Author(s):  
Fanning Zeng ◽  
Valerie Beck ◽  
Sven Schuierer ◽  
Isabelle Garnier ◽  
Carole Manneville ◽  
...  
Keyword(s):  
Live Cell Imaging ◽  
Cell Imaging ◽  
Fluorescent Protein ◽  
Cell Types ◽  
Luciferase Assay ◽  
Primary Cells ◽  
Homology Directed Repair ◽  
Independent Gene ◽  
Protein Tagging ◽  
Selection Of

Genetic knock-in using homology-directed repair is an inefficient process, requiring the selection of few modified cells and hindering its application to primary cells. Here, we describe Homology independent gene Tagging (HiTag), a method to tag a protein of interest by CRISPR in up to 66% of transfected cells with one single electroporation. The technique has proven effective in various cell types and can be used to knock in a fluorescent protein for live cell imaging, to modify the cellular location of a target protein and to monitor the levels of a protein of interest by a luciferase assay in primary cells.

scholarly journals Green fluorescent protein-based lactate and pyruvate indicators suitable for biochemical assays and live cell imaging

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Kazuki Harada ◽  
Takami Chihara ◽  
Yuki Hayasaka ◽  
Marie Mita ◽  
Mai Takizawa ◽  
...  
Keyword(s):  
Live Cell Imaging ◽  
Cell Imaging ◽  
Fluorescent Protein ◽  
Induced Pluripotent Stem Cell ◽  
Cell Types ◽  
Live Cell ◽  
Trace Detection ◽  
Lactate And Pyruvate ◽  
Lactate Levels ◽  
Green Fluorescent

Abstract Glycolysis is the metabolic pathway that converts glucose into pyruvate, whereas fermentation can then produce lactate from pyruvate. Here, we developed single fluorescent protein (FP)-based lactate and pyruvate indicators with low EC50 for trace detection of metabolic molecules and live cell imaging and named them “Green Lindoblum” and “Green Pegassos,” respectively. Green Lindoblum (EC50 of 30 µM for lactate) and Green Pegassos (EC50 of 70 µM for pyruvate) produced a 5.2- and 3.3-fold change in fluorescence intensity in response to lactate and pyruvate, respectively. Green Lindoblum measured lactate levels in mouse plasma, and Green Pegassos in combination with D-serine dehydratase successfully estimated D-serine levels released from mouse primary cultured neurons and astrocytes by measuring pyruvate level. Furthermore, live cell imaging analysis revealed their utility for dual-colour imaging, and the interplay between lactate, pyruvate, and Ca2+ in human induced pluripotent stem cell-derived cardiomyocytes. Therefore, Green Lindoblum and Green Pegassos will be useful tools that detect specific molecules in clinical use and monitor the interplay of metabolites and other related molecules in diverse cell types.

scholarly journals Red-Shifted Aminated Derivatives of GFP Chromophore for Live-Cell Protein Labeling with Lipocalins

2018 ◽  
Vol 19 (12) ◽  
pp. 3778 ◽  
Author(s):  
Nina Bozhanova ◽  
Mikhail Baranov ◽  
Nadezhda Baleeva ◽  
Alexey Gavrikov ◽  
Alexander Mishin
Keyword(s):  
Green Fluorescent Protein ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Fluorescent Protein ◽  
Live Cell ◽  
Protein Labeling ◽  
Cell Protein ◽  
Gfp Chromophore ◽  
Green Fluorescent ◽  
Derivatives Of

Fluorogens are an attractive type of dye for imaging applications, eliminating time-consuming washout steps from staining protocols. With just a handful of reported fluorogen-protein pairs, mostly in the green region of spectra, there is a need for the expansion of their spectral range. Still, the origins of solvatochromic and fluorogenic properties of the chromophores suitable for live-cell imaging are poorly understood. Here we report on the synthesis and labeling applications of novel red-shifted fluorogenic cell-permeable green fluorescent protein (GFP) chromophore analogs.

scholarly journals tdLanYFP, a yellow, bright, photostable and pH insensitive fluorescent protein for live cell imaging and FRET-based sensing strategies

2021 ◽  
Author(s):  
Y. Bousmah ◽  
H. Valenta ◽  
G. Bertolin ◽  
U. Singh ◽  
V. Nicolas ◽  
...  
Keyword(s):  
Single Molecule ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Fluorescent Protein ◽  
Fluorescent Proteins ◽  
Yellow Fluorescent Protein ◽  
Resonance Energy ◽  
Live Cell ◽  
Live Cells

AbstractYellow fluorescent proteins (YFP) are widely used as optical reporters in Förster Resonance Energy Transfer (FRET) based biosensors. Although great improvements have been done, the sensitivity of the biosensors is still limited by the low photostability and the poor fluorescence performances of YFPs at acidic pHs. In fact, today, there is no yellow variant derived from the EYFP with a pK1/2 below ∼5.5. Here, we characterize a new yellow fluorescent protein, tdLanYFP, derived from the tetrameric protein from the cephalochordate B. lanceolatum, LanYFP. With a quantum yield of 0.92 and an extinction coefficient of 133 000 mol−1.L.cm−1, it is, to our knowledge, the brightest dimeric fluorescent protein available, and brighter than most of the monomeric YFPs. Contrasting with EYFP and its derivatives, tdLanYFP has a very high photostability in vitro and preserves this property in live cells. As a consequence, tdLanYFP allows the imaging of cellular structures with sub-diffraction resolution with STED nanoscopy. We also demonstrate that the combination of high brightness and strong photostability is compatible with the use of spectro-microscopies in single molecule regimes. Its very low pK1/2 of 3.9 makes tdLanYFP an excellent tag even at acidic pHs. Finally, we show that tdLanYFP can be a FRET partner either as donor or acceptor in different biosensing modalities. Altogether, these assets make tdLanYFPa very attractive yellow fluorescent protein for long-term or single-molecule live-cell imaging that is also suitable for FRET experiment including at acidic pH.

scholarly journals A versatile reporter system to monitor virus infected cells and its application to dengue virus and SARS-CoV-2

2020 ◽  
Author(s):  
Felix Pahmeier ◽  
Christoper J Neufeldt ◽  
Berati Cerikan ◽  
Vibhu Prasad ◽  
Costantin Pape ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Viral Replication ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Fluorescent Protein ◽  
Live Cell ◽  
Reporter System ◽  
Infected Cells ◽  
Positive Strand Rna

ABSTRACTPositive-strand RNA viruses have been the etiological agents in several major disease outbreaks over the last few decades. Examples of that are flaviviruses, such as dengue virus and Zika virus that cause millions of yearly infections and spread around the globe, and coronaviruses, such as SARS-CoV-2, which is the cause of the current pandemic. The severity of outbreaks caused by these viruses stresses the importance of virology research in determining mechanisms to limit virus spread and to curb disease severity. Such studies require molecular tools to decipher virus-host interactions and to develop effective interventions. Here, we describe the generation and characterization of a reporter system to visualize dengue virus and SARS-CoV-2 replication in live cells. The system is based on viral protease activity causing cleavage and nuclear translocation of an engineered fluorescent protein that is expressed in the infected cells. We show the suitability of the system for live cell imaging and visualization of single infected cells as well as for screening and testing of antiviral compounds. Given the modular building blocks, the system is easy to manipulate and can be adapted to any virus encoding a protease, thus offering a high degree of flexibility.IMPORTANCEReporter systems are useful tools for fast and quantitative visualization of viral replication and spread within a host cell population. Here we describe a reporter system that takes advantage of virus-encoded proteases that are expressed in infected cells to cleave an ER-anchored fluorescent protein fused to a nuclear localization sequence. Upon cleavage, the fluorescent protein translocates to the nucleus, allowing for rapid detection of the infected cells. Using this system, we demonstrate reliable reporting activity for two major human pathogens from the Flaviviridae and the Coronaviridae families: dengue virus and SARS-CoV-2. We apply this reporter system to live cell imaging and use it for proof-of-concept to validate antiviral activity of a nucleoside analogue. This reporter system is not only an invaluable tool for the characterization of viral replication, but also for the discovery and development of antivirals that are urgently needed to halt the spread of these viruses.

scholarly journals CRISPR/dual-FRET molecular beacon for sensitive live-cell imaging of non-repetitive genomic loci

2019 ◽  
Vol 47 (20) ◽  
pp. e131-e131 ◽  
Author(s):  
Shiqi Mao ◽  
Yachen Ying ◽  
Xiaotian Wu ◽  
Christopher J Krueger ◽  
Antony K Chen
Keyword(s):  
Live Cell Imaging ◽  
Cell Imaging ◽  
Molecular Beacon ◽  
Fluorescent Protein ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Dynamic Imaging ◽  
Molecular Beacons ◽  
Imaging Systems ◽  
Guide Rna

Abstract Clustered regularly interspaced short palindromic repeats (CRISPR)-based genomic imaging systems predominantly rely on fluorescent protein reporters, which lack the optical properties essential for sensitive dynamic imaging. Here, we modified the CRISPR single-guide RNA (sgRNA) to carry two distinct molecular beacons (MBs) that can undergo fluorescence resonance energy transfer (FRET) and demonstrated that the resulting system, CRISPR/dual-FRET MB, enables dynamic imaging of non-repetitive genomic loci with only three unique sgRNAs.

Live Cell Imaging of Actin Dynamics in the Filamentous Fungus Aspergillus nidulans

2016 ◽  
Vol 22 (2) ◽  
pp. 264-274 ◽  
Author(s):  
Zachary Schultzhaus ◽  
Laura Quintanilla ◽  
Angelyn Hilton ◽  
Brian D. Shaw
Keyword(s):  
Aspergillus Nidulans ◽  
Filamentous Fungus ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Tip Growth ◽  
Cell Types ◽  
Actin Dynamics ◽  
Growth Site ◽  
The Face ◽  
Over Time

AbstractHyphal cells of filamentous fungi grow at their tips in a method analogous to pollen tube and root hair elongation. This process, generally referred to as tip growth, requires precise regulation of the actin cytoskeleton, and characterizing the various actin structures in these cell types is currently an active area of research. Here, the actin marker Lifeact was used to document actin dynamics in the filamentous fungus Aspergillus nidulans. Contractile double rings were observed at septa, and annular clusters of puncta were seen subtending growing hyphal tips, corresponding to the well-characterized subapical endocytic collar. However, Lifeact also revealed two additional structures. One, an apical array, was dynamic on the face opposite the tip, while a subapical web was dynamic on the apical face and was located several microns behind the growth site. Each was observed turning into the other over time, implying that they could represent different localizations of the same structure, although hyphae with a subapical web grew faster than those exhibiting an apical array. The subapical web has not been documented in any filamentous fungus to date, and is separate from the networks of F-actin seen in other tip-growing organisms surrounding septa or stationary along the plasmalemma.

scholarly journals F-Actin Dynamics in Neurospora crassa

2010 ◽  
Vol 9 (4) ◽  
pp. 547-557 ◽  
Author(s):  
Adokiye Berepiki ◽  
Alexander Lichius ◽  
Jun-Ya Shoji ◽  
Jens Tilsner ◽  
Nick D. Read
Keyword(s):  
Neurospora Crassa ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Fluorescent Protein ◽  
Live Cell ◽  
Actin Dynamics ◽  
Actin Binding ◽  
Content Type ◽  
Actin Cables ◽  
Germ Tubes

ABSTRACT This study demonstrates the utility of Lifeact for the investigation of actin dynamics in Neurospora crassa and also represents the first report of simultaneous live-cell imaging of the actin and microtubule cytoskeletons in filamentous fungi. Lifeact is a 17-amino-acid peptide derived from the nonessential Saccharomyces cerevisiae actin-binding protein Abp140p. Fused to green fluorescent protein (GFP) or red fluorescent protein (TagRFP), Lifeact allowed live-cell imaging of actin patches, cables, and rings in N. crassa without interfering with cellular functions. Actin cables and patches localized to sites of active growth during the establishment and maintenance of cell polarity in germ tubes and conidial anastomosis tubes (CATs). Recurrent phases of formation and retrograde movement of complex arrays of actin cables were observed at growing tips of germ tubes and CATs. Two populations of actin patches exhibiting slow and fast movement were distinguished, and rapid (1.2 μm/s) saltatory transport of patches along cables was observed. Actin cables accumulated and subsequently condensed into actin rings associated with septum formation. F-actin organization was markedly different in the tip regions of mature hyphae and in germ tubes. Only mature hyphae displayed a subapical collar of actin patches and a concentration of F-actin within the core of the Spitzenkörper. Coexpression of Lifeact-TagRFP and β-tubulin–GFP revealed distinct but interrelated localization patterns of F-actin and microtubules during the initiation and maintenance of tip growth.

scholarly journals Mouse models of MYH9-related disease: mutations in nonmuscle myosin II-A

Blood ◽  
2012 ◽  
Vol 119 (1) ◽  
pp. 238-250 ◽  
Author(s):  
Yingfan Zhang ◽  
Mary Anne Conti ◽  
Daniela Malide ◽  
Fan Dong ◽  
Aibing Wang ◽  
...  
Keyword(s):  
Live Cell Imaging ◽  
Cell Imaging ◽  
Fluorescent Protein ◽  
Myosin Ii ◽  
Nonmuscle Myosin ◽  
Clot Retraction ◽  
Related Disease ◽  
Disease Mutations ◽  
Nonmuscle Myosin Ii ◽  
Green Fluorescent

Abstract We have generated 3 mouse lines, each with a different mutation in the nonmuscle myosin II-A gene, Myh9 (R702C, D1424N, and E1841K). Each line develops MYH9-related disease similar to that found in human patients. R702C mutant human cDNA fused with green fluorescent protein was introduced into the first coding exon of Myh9, and D1424N and E1841K mutations were introduced directly into the corresponding exons. Homozygous R702C mice die at embryonic day 10.5-11.5, whereas homozygous D1424N and E1841K mice are viable. All heterozygous and homozygous mutant mice show macrothrombocytopenia with prolonged bleeding times, a defect in clot retraction, and increased extramedullary megakaryocytes. Studies of cultured megakaryocytes and live-cell imaging of megakaryocytes in the BM show that heterozygous R702C megakaryocytes form fewer and shorter proplatelets with less branching and larger buds. The results indicate that disrupted proplatelet formation contributes to the macrothrombocytopenia in mice and most probably in humans. We also observed premature cataract formation, kidney abnormalities, including albuminuria, focal segmental glomerulosclerosis and progressive kidney disease, and mild hearing loss. Our results show that heterozygous mice with mutations in the myosin motor or filament-forming domain manifest similar hematologic, eye, and kidney phenotypes to humans with MYH9-related disease.

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