Novel fluorescent protein from Discosoma coral and its mutants possesses a unique far-red fluorescence

FEBS Letters ◽  
2000 ◽  
Vol 479 (3) ◽  
pp. 127-130 ◽  
Author(s):  
Arkady F. Fradkov ◽  
Ying Chen ◽  
Li Ding ◽  
Ekaterina V. Barsova ◽  
Mikhail V. Matz ◽  
...  
2012 ◽  
Vol 24 (04) ◽  
pp. 333-341 ◽  
Author(s):  
Shan-Wen Liu ◽  
Kuan-Hung Cho ◽  
Mei-Ru Chen ◽  
Hsiao-Chi Yu ◽  
Yu-Ying Kao ◽  
...  

In this report, we generated a ferritin and red fluorescent protein fusion reporter gene that enables the visualization of transgene expression in living animals by magnetic resonance imaging (MRI) and optical imaging. Ferritin heavy chain (FTH) or light chain (FTL) was linked to the N terminus of the monomeric DsRed red fluorescent protein to create FTH-DsRed and FTL-DsRed, MRI-fluorescence dual reporters. Transfection of these dual reporters into cells resulted in increased iron loading and strong red fluorescence in cells. Adenoviral vectors to express FTH-DsRed or FTL-DsRed fusion reporter in infected cells were created, but only the adenovirus expressing FTH-DsRed resulted in a high level of red fluorescence in cells. Delivery and expression of FTH-DsRed in the mouse brain using adenovirus was detected by MRI and fluorescence imaging, revealing a T2shortening effect and an increase of contrast in T2-weighted images at the sites co-localized with strong red fluorescence. While the details of the structure of ferritin-DsRed fusion reporter remains to be solved, this dual reporter is useful for visualizing dynamic processes such as the migration of reporter-transfected stem cells or metastasis of tumors using MRI with the added flexibility of combining optical tools such as fluorescence activated cell sorting and fluorescence microscopy.


2022 ◽  
Author(s):  
Thanh Vu Nguyen ◽  
Bui Hoang Loc ◽  
Nguyen Hoang Thuy Vy ◽  
Dinh Thi Thuy

Abstract Angelfish (Pterophyllum sp.) are attractive fish popular with aquarists. The introduction of fluorescent protein genes into angelfish has been reported, but specific techniques have not been revealed. This study aimed to develop a strategy to produce red fluorescent protein (RFP) transgenic angelfish driven by the myosin light chain 2 (mylz2) promoter from zebrafish. A 1999 bp Mylz2 promoter fragment was isolated from zebrafish muscle genomic DNA. This promoter fragment was then cloned into the plasmid pDsred2-1 open-loop at restriction enzyme SacI and AgeI sites to create the final transgene construct pMylz2-RFP. Angelfish embryos at one cell stage were microinjected with approximately 100 pg of the plasmid pMylz2-RFP. From 524 microinjected embryos, 16 successfully hatched, while 12 showed red fluorescence signals. Two larvae survived to 2 months of age. They showed significant red fluorescence expression in the muscles, suggesting that the angelfish could be used as potential transgenic founders to evaluate the next generation of stable red fluorescence expression transgenic fish.


FEBS Letters ◽  
2022 ◽  
Author(s):  
Keerti Yadav ◽  
Swagatha Ghosh ◽  
Arvind Barak ◽  
Wayne Schaefer ◽  
Ramaswamy Subramanian

Parasitology ◽  
2009 ◽  
Vol 136 (6) ◽  
pp. 579-588 ◽  
Author(s):  
A. UNNO ◽  
K. SUZUKI ◽  
T. BATANOVA ◽  
S.-Y. CHA ◽  
H.-K. JANG ◽  
...  

SUMMARYTo recognize the stage conversion ofToxoplasma gondiibetween tachyzoite and bradyzoite in live host cells, a transgenicT. gondiiline, which expressed stage-specific red and green fluorescence, was constructed.T. gondiiPLK strain tachyzoites were stably transformed with genes encoding red fluorescent protein (DsRed Express) and green fluorescent protein (GFP) under the control of tachyzoite-specific SAG1 and bradyzoite-specific BAG1 promoters, respectively. The resulting transgenic parasite was designated PLK/DUAL. When PLK/DUAL was cultured in pH 7·0 medium, the PLK/DUAL zoites expressed red fluorescence, but no detectable levels of green fluorescence were observed. The PLK/DUAL zoites reacted with anti-SAG1 antibody, but not anti-BAG1 antiserum. When PLK/DUAL was cultured under high pH conditions, or in the presence of the p38 MAPK inhibitor SB202190, a small number of zoites expressed green fluorescence and were BAG1 positive. C57BL/6J mice were infected with PLK/DUAL tachyzoites. During the acute and reactivating phase, zoites expressed red fluorescence. However, green fluorescence was not detectable. By contrast, latent cysts expressed green fluorescence. The stage-specific dual fluorescence of PLK/DUAL facilitates identification of the parasitic stage in live cells, with the advantage that fixation or immunostaining is not required.


2020 ◽  
Vol 48 (6) ◽  
pp. 2657-2667
Author(s):  
Felipe Montecinos-Franjola ◽  
John Y. Lin ◽  
Erik A. Rodriguez

Noninvasive fluorescent imaging requires far-red and near-infrared fluorescent proteins for deeper imaging. Near-infrared light penetrates biological tissue with blood vessels due to low absorbance, scattering, and reflection of light and has a greater signal-to-noise due to less autofluorescence. Far-red and near-infrared fluorescent proteins absorb light >600 nm to expand the color palette for imaging multiple biosensors and noninvasive in vivo imaging. The ideal fluorescent proteins are bright, photobleach minimally, express well in the desired cells, do not oligomerize, and generate or incorporate exogenous fluorophores efficiently. Coral-derived red fluorescent proteins require oxygen for fluorophore formation and release two hydrogen peroxide molecules. New fluorescent proteins based on phytochrome and phycobiliproteins use biliverdin IXα as fluorophores, do not require oxygen for maturation to image anaerobic organisms and tumor core, and do not generate hydrogen peroxide. The small Ultra-Red Fluorescent Protein (smURFP) was evolved from a cyanobacterial phycobiliprotein to covalently attach biliverdin as an exogenous fluorophore. The small Ultra-Red Fluorescent Protein is biophysically as bright as the enhanced green fluorescent protein, is exceptionally photostable, used for biosensor development, and visible in living mice. Novel applications of smURFP include in vitro protein diagnostics with attomolar (10−18 M) sensitivity, encapsulation in viral particles, and fluorescent protein nanoparticles. However, the availability of biliverdin limits the fluorescence of biliverdin-attaching fluorescent proteins; hence, extra biliverdin is needed to enhance brightness. New methods for improved biliverdin bioavailability are necessary to develop improved bright far-red and near-infrared fluorescent proteins for noninvasive imaging in vivo.


2019 ◽  
Author(s):  
Chi-Yun Lin ◽  
Matthew Romei ◽  
Luke Oltrogge ◽  
Irimpan Mathews ◽  
Steven Boxer

Green fluorescent protein (GFPs) have become indispensable imaging and optogenetic tools. Their absorption and emission properties can be optimized for specific applications. Currently, no unified framework exists to comprehensively describe these photophysical properties, namely the absorption maxima, emission maxima, Stokes shifts, vibronic progressions, extinction coefficients, Stark tuning rates, and spontaneous emission rates, especially one that includes the effects of the protein environment. In this work, we study the correlations among these properties from systematically tuned GFP environmental mutants and chromophore variants. Correlation plots reveal monotonic trends, suggesting all these properties are governed by one underlying factor dependent on the chromophore's environment. By treating the anionic GFP chromophore as a mixed-valence compound existing as a superposition of two resonance forms, we argue that this underlying factor is defined as the difference in energy between the two forms, or the driving force, which is tuned by the environment. We then introduce a Marcus-Hush model with the bond length alternation vibrational mode, treating the GFP absorption band as an intervalence charge transfer band. This model explains all the observed strong correlations among photophysical properties; related subtopics are extensively discussed in Supporting Information. Finally, we demonstrate the model's predictive power by utilizing the additivity of the driving force. The model described here elucidates the role of the protein environment in modulating photophysical properties of the chromophore, providing insights and limitations for designing new GFPs with desired phenotypes. We argue this model should also be generally applicable to both biological and non-biological polymethine dyes.<br>


2019 ◽  
Author(s):  
Adam Beachey ◽  
Harley Worthy ◽  
William David Jamieson ◽  
Suzanne Thomas ◽  
Benjamin Bowen ◽  
...  

<p>Functional integration of proteins with carbon-based nanomaterials such as nanotubes holds great promise in emerging electronic and optoelectronic applications. Control over protein attachment poses a major challenge for consistent and useful device fabrication, especially when utilizing single/few molecule properties. Here, we exploit genetically encoded phenyl azide photochemistry to define the direct covalent attachment of three different proteins, including the fluorescent protein GFP, to carbon nanotube side walls. Single molecule fluorescence revealed that on attachment to SWCNTs GFP’s fluorescence changed in terms of intensity and improved resistance to photobleaching; essentially GFP is fluorescent for much longer on attachment. The site of attachment proved important in terms of electronic impact on GFP function, with the attachment site furthest from the functional center having the larger effect on fluorescence. Our approach provides a versatile and general method for generating intimate protein-CNT hybrid bioconjugates. It can be potentially applied easily to any protein of choice; attachment position and thus interface characteristics with the CNT can easily be changed by simply placing the phenyl azide chemistry at different residues by gene mutagenesis. Thus, our approach will allow consistent construction and modulate functional coupling through changing the protein attachment position.</p>


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