%0 Journal Article
%T Single fluorescent protein-based Ca2+ sensors with increased dynamic range
%A Ekaterina A Souslova
%A Vsevolod V Belousov
%A John G Lock
%A Staffan Str£żmblad
%A Sergey Kasparov
%A Alexey P Bolshakov
%A Vsevolod G Pinelis
%A Yulii A Labas
%A Sergey Lukyanov
%A Lorenz M Mayr
%A Dmitriy M Chudakov
%J BMC Biotechnology
%D 2007
%I BioMed Central
%R 10.1186/1472-6750-7-37
%X Here we report significant progress on the development of the latter type of Ca2+ sensors. Derived from the knowledge of previously reported cpFP-based sensors, we generated a set of cpFP-based indicators with different spectral properties and fluorescent responses to changes in Ca2+ concentration. Two variants, named Case12 and Case16, were characterized by particular high brightness and superior dynamic range, up to 12-fold and 16.5-fold increase in green fluorescence between Ca2+-free and Ca2+-saturated forms. We demonstrated the high potential of these sensors on various examples, including monitoring of Ca2+ response to a prolonged glutamate treatment in cortical neurons.We believe that expanded dynamic range, high brightness and relatively high pH-stability should make Case12 and Case16 popular research tools both in scientific studies and high throughput screening assays.An increasing number of genetically encoded fluorescent sensors have recently been developed on the basis of GFP-like proteins [1-3]. However, currently available genetically encoded sensors are characterized by low signal intensity and limited dynamic range (maximum change in fluorescence ratio or intensity) [1,4,5], insufficient for routine applications in high throughput screening (HTS) assays and restricting sensitivity of precise single-cell studies. At the same time, genetically encoded sensors provide a much wider flexibility, allowing to be targeted to any chosen cellular compartment, to generate stable cell lines and transgenic animals, to be expressed in a particular tissue and/or in a temporally controlled manner under a specific promoter. Therefore, development of genetically encoded sensors characterized by increased dynamic range and signal intensity remains an actual task.One of the most promising approaches to create genetically encoded sensors is based on the circularly permuted fluorescent protein (cpFP) fused to or inserted into sensitive domain(s) [6-12]. In the presence o
%U http://www.biomedcentral.com/1472-6750/7/37