Jasper Akerboom, Nicole Carreras Calderón, Lin Tian, Sebastian Wabnig, Matthias Prigge, Johan Tolö, Andrew Gordus, Michael B Orger, Kristen E Severi, John J Macklin, Ronak Patel, Stefan R Pulver, Trevor J Wardill, Elisabeth Fischer, Christina Schüler, Tsai-Wen Chen, Karen S Sarkisyan, Jonathan S Marvin, Cornelia I Bargmann, Douglas S Kim, Sebastian Kügler, Leon Lagnado, Peter Hegemann, Alexander Gottschalk, Eric R Schreiter, Loren L Looger
Genetically encoded calcium indicators (GECIs) are powerful tools for systems neuroscience. Here we describe red, single-wavelength GECIs, "RCaMPs," engineered from circular permutation of the thermostable red fluorescent protein mRuby. High-resolution crystal structures of mRuby, the red sensor RCaMP, and the recently published red GECI R-GECO1 give insight into the chromophore environments of the Ca(2+)-bound state of the sensors and the engineered protein domain interfaces of the different indicators. We characterized the biophysical properties and performance of RCaMP sensors in vitro and in vivo in Caenorhabditis elegans, Drosophila larvae, and larval zebrafish...
2013: Frontiers in Molecular Neuroscience