Patent ID: 8304198

Claim:
A assay for quantitation of transient intracellular calcium with a set of pairs of protein components having different levels of sensitivity to concentration of calcium comprising: i) generating an expression construct for fusion proteins having Ca 2+ /calmodulin dependent protein kinase II (CaMKII) phosphorylation sites of NR2A or NR2B subunits of N-methyl-D-aspartate (NMDA) receptor or the voltage gated potassium channel of Drosophila Eag, conjugated to a mitochondrial localizing signal sequence to form MLS-NR2A, MLS-NR2B, or MLS-Eaq; ii) generating a mammalian expression construct for a chimeric protein having α-CaMKII and green fluorescent protein (GFP-α-CaMKII); iii) subjecting the constructs to the step of site-directed mutagenesis; and iv) subjecting the constructs to the step of transfection, Ca 2+ stimulation, imaging and quantification of the number of cells with Ca 2+ dependent signal, wherein NMDA receptor activity assay, TRPVI receptor activity assay, GIuR4 receptor activity assay are performed to detect the activity of Ca 2+ channel proteins.