Structural insight into enhanced calcium indicator GCaMP3 and GCaMPJ to promote further improvement
Protein & Cell
;
(12): 299-309, 2013.
Article
in English
| WPRIM
| ID: wpr-757810
ABSTRACT
Genetically encoded Ca(2+) indicators (GECI) are important for the measurement of Ca(2+) in vivo. GCaMP2, a widely-used GECI, has recently been iteratively improved. Among the improved variants, GCaMP3 exhibits significantly better fluorescent intensity. In this study, we developed a new GECI called GCaMPJ and determined the crystal structures of GCaMP3 and GCaMPJ. GCaMPJ has a 1.5-fold increase in fluorescence and 1.3-fold increase in calcium affinity over GCaMP3. Upon Ca(2+) binding, GCaMP3 exhibits both monomeric and dimeric forms. The structural superposition of these two forms reveals the role of Arg-376 in improving monomer performance. However, GCaMPJ seldom forms dimers under conditions similar to GCaMP3. St ructural and mutagenesis studies on Tyr-380 confirmed its importance in blocking the cpEGFP β-barrel holes. Our study proposes an efficient tool for mapping Ca(2+) signals in intact organs to facilitate the further improvement of GCaMP sensors.
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Peptide Fragments
/
Myosin-Light-Chain Kinase
/
Recombinant Fusion Proteins
/
Calmodulin
/
Chemistry
/
Calcium
/
Protein Structure, Tertiary
/
Crystallography, X-Ray
/
Dimerization
/
Green Fluorescent Proteins
Language:
English
Journal:
Protein & Cell
Year:
2013
Type:
Article
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