scholarly journals A red fluorescent protein with improved monomericity enables ratiometric voltage imaging with ASAP3

2020 ◽  
Author(s):  
Benjamin B. Kim ◽  
Haodi Wu ◽  
Yukun A. Hao ◽  
Michael Pan ◽  
Mariya Chavarha ◽  
...  
Keyword(s):  
High Performance ◽  
Fluorescent Protein ◽  
Fluorescent Proteins ◽  
High Gain ◽  
Motion Artifacts ◽  
Red Fluorescent Protein ◽  
Red Fluorescent Proteins ◽  
Transmembrane Voltage ◽  
Site Mutagenesis ◽  
Green Fluorescent

AbstractA ratiometric genetically encoded voltage indicator (GEVI) would be desirable for tracking transmembrane voltage changes in cells that are undergoing motion. To create a high-performance ratiometric GEVI, we explored the possibility of adding a voltage-independent red fluorophore to ASAP3, a high-gain green fluorescent GEVI. We performed combinatorial multi-site mutagenesis on the cyan-excitable red fluorescent protein mCyRFP1 to enhance brightness and monomericity, creating mCyRFP3. Among red fluorescent proteins tested, mCyRFP3 proved to be the least perturbing when fused to ASAP3. We demonstrate that the red fluorescence of ASAP3-mCyRFP3 (ASAP3-R3) provides an effective reference channel to remove motion artifacts from voltage-induced changes in green fluorescence. Finally we use ASAP3-R3 to visualize membrane voltage changes throughout the cell cycle of motile cells.

ESTABLISHMENT OF VISIBLE ANIMAL METASTASIS MODELS FOR HUMAN NASOPHARYNGEAL CARCINOMA BASED ON A FAR-RED FLUORESCENT PROTEIN

2012 ◽  
Vol 05 (03) ◽  
pp. 1250019 ◽  
Author(s):  
YING ZHENG ◽  
CHUAN HUANG ◽  
ZHIYONG CHENG ◽  
MIN CHEN
Keyword(s):  
Nasopharyngeal Carcinoma ◽  
Animal Models ◽  
Tumor Growth ◽  
Cell Line ◽  
Fluorescent Protein ◽  
Fluorescent Proteins ◽  
Expression Vectors ◽  
Red Fluorescent Protein ◽  
Red Fluorescent Proteins ◽  
Metastasis Model

Background and aims: The spectral properties of enhanced green fluorescent protein (EGFP) used in current visualizable animal models for nasopharyngeal carcinoma (NPC) result in a limited imaging depth. Far-red fluorescent proteins have optimal spectral wavelengths that allow deep tissue penetration, thus are well-suited for the imaging of tumor growth and metastases in live animals. This study aims to establish an imageable animal model of NPC using far-red fluorescent proteins. Methods: Eukaryotic expression vectors of far-red fluorescent proteins, mLumin and Katushka S158A, were separately transfected into 5-8F NPC cells, and cell lines stably expressing the far-red fluorescent proteins were obtained. These cells were intraperitoneally or intravenously injected into mice, and their tumorigenic and metastatic potential were examined through fluorescence imaging. Finally, factors affecting their tumorigenic ability were further assessed through testing side population (SP) cells proportion by flow cytometry. Results: NPC cell line with high tumorigenicity and metastasis (5-8F-mL2) was screened out, which stably expressed far-red fluorescent protein. Intraperitoneal and intravenous injection of 5-8F-mL2 cells resulted in an abdomen metastasis model and a lung metastasis model. In addition, NPC cell line without tumorigenicity (5-8F-Katushka S158A) was screened out. The percentage of SP cells between 5-8F-mL2 and 5-8F-Katushka S158A was found different, suggesting that the SP cell proportion may play a key role in the determination of cell tumorigenic ability. Conclusion: We successfully established animal models for NPC with high tumorigenicity and metastasis using a super-bright far-red fluorescent protein. Owing to the super-brightness and excellent wavelength parameters, these models may be applied as useful tools for intuitive and efficient monitoring of tumor growth and metastasis, as well as assessing the efficacy of nasopharyngeal cancer drugs.

Color morphs of the coral, Acropora tenuis, show different responses to environmental stress and different expression profiles of fluorescent-protein genes

2020 ◽  
Author(s):  
Noriyuki Satoh ◽  
Koji Kinjo ◽  
Kohei Shintaku ◽  
Daisuke Kezuka ◽  
Hiroo Ishimori ◽  
...  
Keyword(s):  
Fluorescent Protein ◽  
Fluorescent Proteins ◽  
Expression Profiles ◽  
Biological Significance ◽  
Gene Expression Profiles ◽  
Gfp Expression ◽  
Red Fluorescent Proteins ◽  
Color Morphs ◽  
Acropora Tenuis ◽  
Green Fluorescent

ABSTRACTCorals of the family Acroporidae are key structural components of reefs that support the most diverse marine ecosystems. Due to increasing anthropogenic stresses, coral reefs are in decline. Along the coast of Okinawa, Japan, three different color morphs of Acropora tenuis have been recognized for decades. These include brown (N morph), yellow-green (G) and purple (P) forms. The tips of axial coral polyps exhibit specific fluorescence spectra. This attribute is inherited asexually, and color morphs do not change seasonally. In Okinawa Prefecture, during the summer of 2017, the N and P morphs experienced bleaching, in which some N morphs died while P morphs recovered. In contrast, G morphs successfully withstood the stress. Symbiotic dinoflagellates are essential symbiotic partners of scleractinian corals. Photosynthetic activity of symbionts was reduced in July in N and P morphs; however, the three color-morphs host similar sets of Clade-C zoothanthellae, suggesting that beaching of N and P morphs cannot be attributed to differences in symbiont clades. The decoded Acropora tenuis genome includes five genes for green fluorescent proteins (GFP), two for cyan fluorescent proteins (CFP), three for red fluorescent proteins (RFP), and seven genes for chromoprotein (ChrP). A summer survey of gene expression profiles demonstrated that (a) expression of CFP and REP was quite low in all three morphs, (b) P morphs expressed higher levels of ChrP, (c) both N and G morphs expressed GFP highly, and (d) GFP expression was reduced in N morphs, compared to G morphs, which maintained higher levels of GFP expression throughout the summer. Although further studies are required to understand the biological significance of these color morphs of Acropora tenuis, our results suggest that thermal stress resistance is modified by genetic mechanisms that coincidentally lead to diversification of color morphs.

scholarly journals Incomplete proteasomal degradation of green fluorescent proteins in the context of tandem fluorescent protein timers

2015 ◽  
Author(s):  
Anton Khmelinskii ◽  
Matthias Meurer ◽  
Chi-Ting Ho ◽  
Birgit Besenbeck ◽  
Julia Fueller ◽  
...  
Keyword(s):  
Protein Turnover ◽  
Fluorescent Protein ◽  
Fluorescent Proteins ◽  
Proteasomal Degradation ◽  
Time Range ◽  
Green Fluorescent Proteins ◽  
Red Fluorescent Proteins ◽  
Dependent Change ◽  
The Stability ◽  
Green Fluorescent

Tandem fluorescent protein timers (tFTs) report on protein age through time-dependent change in color, which can be exploited to study protein turnover and trafficking. Each tFT, composed of two fluorescent proteins (FPs) that differ in maturation kinetics, is suited to follow protein dynamics within a specific time range determined by the maturation rates of both FPs. So far tFTs were constructed by combining different slower-maturing red fluorescent proteins (redFPs) with the same faster-maturing superfolder green fluorescent protein (sfGFP). Towards a comprehensive characterization of tFTs, we compare here tFTs composed of different faster-maturing greenFPs, while keeping the slower-maturing redFP constant (mCherry). Our results indicate that the greenFP maturation kinetics influences the time range of a tFT. Moreover, we observe that commonly used greenFPs can partially withstand proteasomal degradation due to the stability of the FP fold, which results in accumulation of tFT fragments in the cell. Depending on the order of FPs in the timer, incomplete proteasomal degradation either shifts the time range of the tFT towards slower time scales or precludes its use for measurements of protein turnover. We identify greenFPs that are efficiently degraded by the proteasome and provide simple guidelines for design of new tFTs.

scholarly journals mCherry contains a fluorescent protein isoform that interferes with its reporter function

2021 ◽  
Author(s):  
Maxime Fages-Lartaud ◽  
Lisa Tietze ◽  
Florence Elie ◽  
Rahmi Lale ◽  
Martin Frank Hohmann-Marriott
Keyword(s):  
Cell Biology ◽  
Fluorescent Protein ◽  
Fluorescent Proteins ◽  
Initiation Site ◽  
Translation Initiation Site ◽  
Red Fluorescent Protein ◽  
Functional Protein ◽  
Red Fluorescent Proteins ◽  
Expression Studies ◽  
Protein Isoform

AbstractFluorescent proteins are essential reporters in cell biology and molecular biology. Here, we reveal that red-fluorescent proteins possess an alternative translation initiation site that produces a short functional protein isoform. The short isoform creates significant background fluorescence that biases the outcome of expression studies. Our investigation identifies the short protein isoform, traces its origin, and determines the extent of the issue within the family of red fluorescent protein. Our analysis shows that the short isoform defect of the red fluorescent protein family may affect the interpretation of many published studies. Finally, we provide a re-engineered mCherry variant that lacks background expression as an improved tool for imaging and protein expression studies.

scholarly journals Red Fluorescent Protein (DsRed) as a Reporter inSaccharomyces cerevisiae

2001 ◽  
Vol 183 (12) ◽  
pp. 3791-3794 ◽  
Author(s):  
Fernando Rodrigues ◽  
Martijn van Hemert ◽  
H. Yde Steensma ◽  
Manuela Côrte-Real ◽  
Cecı́la Leão
Keyword(s):  
Nuclear Localization ◽  
Fluorescent Protein ◽  
Fluorescent Proteins ◽  
Green Fluorescent Proteins ◽  
Red Fluorescent Protein ◽  
Amino Terminal ◽  
Carboxyl Terminal ◽  
Dsred Protein ◽  
Green Fluorescent

ABSTRACT We describe the utilization of a red fluorescent protein (DsRed) as an in vivo marker for Saccharomyces cerevisiae. Clones expressing red and/or green fluorescent proteins with both cytoplasmic and nuclear localization were obtained. A series of vectors are now available which can be used to create amino-terminal (N-terminal) and carboxyl-terminal (C-terminal) fusions with the DsRed protein.

scholarly journals Far-red fluorescent proteins evolved from a blue chromoprotein from Actinia equina

2005 ◽  
Vol 392 (3) ◽  
pp. 649-654 ◽  
Author(s):  
Maria A. Shkrob ◽  
Yurii G. Yanushevich ◽  
Dmitriy M. Chudakov ◽  
Nadya G. Gurskaya ◽  
Yulii A. Labas ◽  
...  
Keyword(s):  
Fluorescent Protein ◽  
Fluorescent Proteins ◽  
Bathochromic Shift ◽  
Random Mutagenesis ◽  
Basal Disc ◽  
Red Fluorescent Proteins ◽  
Stable Mutant ◽  
Basal Disk ◽  
Green Fluorescent ◽  
Blue Circle

Proteins of the GFP (green fluorescent protein) family demonstrate a great spectral and phylogenetic diversity. However, there is still an intense demand for red-shifted GFP-like proteins in both basic and applied science. To obtain GFP-like chromoproteins with red-shifted absorption, we performed a broad search in blue-coloured Anthozoa species. We revealed specimens of Actinia equina (beadlet anemone) exhibiting a bright blue circle band at the edge of the basal disc. A novel blue chromoprotein, aeCP597, with an absorption maximum at 597 nm determining the coloration of the anemone basal disk was cloned. AeCP597 carries a chromophore chemically identical with that of the well-studied DsRed (red fluorescent protein from Discosoma sp.). Thus a strong 42-nm bathochromic shift of aeCP597 absorption compared with DsRed is determined by peculiarities of chromophore environment. Site-directed and random mutagenesis of aeCP597 resulted in far-red fluorescent mutants with emission maxima at up to 663 nm. The most bright and stable mutant AQ143 possessed excitation and emission maxima at 595 and 655 nm respectively. Thus aeCP597 and its fluorescent mutants set a new record of red-shifted absorption and emission maxima among GFP-like proteins.

scholarly journals A bright and high-performance genetically encoded Ca2+ indicator based on mNeonGreen fluorescent protein

2020 ◽  
Author(s):  
Landon Zarowny ◽  
Abhi Aggarwal ◽  
Virginia M.S. Rutten ◽  
Ilya Kolb ◽  
Ronak Patel ◽  
...  
Keyword(s):  
High Performance ◽  
Fluorescent Protein ◽  
Cultured Cells ◽  
Fluorescent Proteins ◽  
Model Organisms ◽  
Green Fluorescent Proteins ◽  
Comparable Performance ◽  
Green Fluorescent

AbstractGenetically encodable calcium ion (Ca2+) indicators (GECIs) based on green fluorescent proteins (GFP) are powerful tools for imaging of cell signaling and neural activity in model organisms. Following almost two decades of steady improvements in the Aequorea victoria GFP (avGFP)-based GCaMP series of GECIs, the performance of the most recent generation (i.e., GCaMP7) may have reached its practical limit due to the inherent properties of GFP. In an effort to sustain the steady progression towards ever-improved GECIs, we undertook the development of a new GECI based on the bright monomeric GFP, mNeonGreen (mNG). The resulting indicator, mNG-GECO1, is 60% brighter than GCaMP6s in vitro and provides comparable performance as demonstrated by imaging Ca2+ dynamics in cultured cells, primary neurons, and in vivo in larval zebrafish. These results suggest that mNG-GECO1 is a promising next-generation GECI that could inherit the mantle of GCaMP and allow the steady improvement of GECIs to continue for generations to come.

scholarly journals mBeRFP, a versatile fluorescent tool to enhance multichannel live imaging and its applications

2022 ◽  
Author(s):  
Emmanuel Martin ◽  
Magali Suzanne
Keyword(s):  
Fluorescent Protein ◽  
Fluorescent Proteins ◽  
Stokes Shift ◽  
Live Imaging ◽  
Red Fluorescent Protein ◽  
Red Fluorescent Proteins ◽  
Living Organisms ◽  
Illumination Source

Cell and developmental biology increasingly require live imaging of protein dynamics in cells, tissues or living organisms. Thanks to the discovery and the development of a panel of fluorescent proteins over the last decades, live imaging has become a powerful and commonly used approach. However, multicolor live imaging remains challenging. The generation of long Stokes shift red fluorescent proteins, such as mBeRFP, offers interesting new perspectives to bypass this limitation. Here, we constructed a set of mBeRFP-expressing vectors and provided a detailed characterization of this fluorescent protein for in vivo live imaging and its applications in Drosophila. Briefly, we showed that a single illumination source is sufficient to simultaneously stimulate mBeRFP and GFP. We demonstrated that mBeRFP can be easily combined with classical green and red fluorescent protein without any crosstalk. We also showed that the low photobleaching of mBeRFP is suitable for live imaging, and that this protein can be used for quantitative applications such as FRAP or laser ablation. Finally, we believe that this fluorescent protein, with the set of new possibilities it offers, constitutes an important tool for cell, developmental and mechano biologists in their current research.

scholarly journals Color morphs of the coral, Acropora tenuis, show different responses to environmental stress and different expression profiles of fluorescent-protein genes

2021 ◽  
Vol 11 (2) ◽  
Author(s):  
Noriyuki Satoh ◽  
Koji Kinjo ◽  
Kohei Shintaku ◽  
Daisuke Kezuka ◽  
Hiroo Ishimori ◽  
...  
Keyword(s):  
Fluorescent Protein ◽  
Fluorescent Proteins ◽  
Expression Profiles ◽  
Biological Significance ◽  
Gene Expression Profiles ◽  
Gfp Expression ◽  
Red Fluorescent Proteins ◽  
Color Morphs ◽  
Acropora Tenuis ◽  
Green Fluorescent

Abstract Corals of the family Acroporidae are key structural components of reefs that support the most diverse marine ecosystems. Due to increasing anthropogenic stresses, coral reefs are in decline. Along the coast of Okinawa, Japan, three different color morphs of Acropora tenuis have been recognized for decades. These include brown (N morph), yellow green (G), and purple (P) forms. The tips of axial polyps of each morph exhibit specific fluorescence spectra. This attribute is inherited asexually, and color morphs do not change seasonally. In Okinawa Prefecture, during the summer of 2017, N and P morphs experienced bleaching, in which many N morphs died. Dinoflagellates (Symbiodiniaceae) are essential partners of scleractinian corals, and photosynthetic activity of symbionts was reduced in N and P morphs. In contrast, G morphs successfully withstood the stress. Examination of the clade and type of Symbiodiniaceae indicated that the three color-morphs host similar sets of Clade-C symbionts, suggesting that beaching of N and P morphs is unlikely attributable to differences in the clade of Symbiodiniaceae the color morphs hosted. Fluorescent proteins play pivotal roles in physiological regulation of corals. Since the A. tenuis genome has been decoded, we identified five genes for green fluorescent proteins (GFPs), two for cyan fluorescent proteins (CFPs), three for red fluorescent proteins (RFPs), and seven genes for chromoprotein (ChrP). A summer survey of gene expression profiles under outdoor aquarium conditions demonstrated that (a) expression of CFP and REP was quite low during the summer in all three morphs, (b) P morphs expressed higher levels of ChrP than N and G morphs, (c) both N and G morphs expressed GFP more highly than P morphs, and (d) GFP expression in N morphs was reduced during summer whereas G morphs maintained high levels of GFP expression throughout the summer. Although further studies are required to understand the biological significance of these color morphs of A. tenuis, our results suggest that thermal stress resistance is modified by genetic mechanisms that coincidentally lead to diversification of color morphs of this coral.

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