EMSA of the NFAT Binding in the Rat GHRH Promoter A probe containing the consensus NFAT-binding sequence located in the rat insulin I gene and the probes corresponding to sites1 to 5 were biotin-labeled and incubated with the whole cell lysate extracted from the NFAT-overexpressed Gsh+/+ cells, followed by electrophoresis (see Materials and Methods). Competition experiments were carried out using 500-fold molar excess of the unlabeled probe.