Structural insight into enhanced calcium indicator GCaMP3 and GCaMPJ to promote further improvement
Protein & Cell
; (12): 299-309, 2013.
Article
em En
| WPRIM
| ID: wpr-757810
Biblioteca responsável:
WPRO
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.
Texto completo:
1
Índice:
WPRIM
Assunto principal:
Fragmentos de Peptídeos
/
Quinase de Cadeia Leve de Miosina
/
Proteínas Recombinantes de Fusão
/
Calmodulina
/
Química
/
Cálcio
/
Estrutura Terciária de Proteína
/
Cristalografia por Raios X
/
Dimerização
/
Proteínas de Fluorescência Verde
Idioma:
En
Revista:
Protein & Cell
Ano de publicação:
2013
Tipo de documento:
Article