ELK Responsive Luciferase Reporter HEK293 Cell Line is derived from human embryonic kidney, and stably expresses firefly luciferase reporter gene under the control of ELK response element. This cell line is an ideal cellular model for monitoring the activation of MAPK response Pathway triggered by stimuli treatment, enforced gene expression, and gene knockdown.
 
Mitogen-activated protein kinase (MAPK) signaling pathways mediate important eukaryotic transcriptional responses to extracellular signals that begin at the cell surface. While different external stimuli may activate distinct MAPK signaling pathways, many MAPK pathways later converge in the activation of ETS domain transcription factor ELK1. ELK1 is a major nuclear substrate for MAPKs, JNK, p38, and ERK pathways, where phosphorylation of ELK1 by these kinases results in a conformational change of ELK1 and triggers its DNA binding activity. 
 
Signosis has established an ELK-TAD luciferase reporter stable cell line. This cell line expresses a fusion protein linking the DNA transactivation domain (TAD) of ELK to Gal4. As the TAD is phosphorylated, this Gal4 fusion protein will drive luciferase expression controlled by Gal4-UAS. This cell line can act as a reporter system to monitor ELK1-dependent transcriptional activity and MAPK signaling, as triggered by stimuli treatment, enforced gene expression and gene knockdown.
 
Principle behind TF luciferase reporter. TF luciferase reporter stable cell line utilizes artificial promoter constructs to drive luciferase expression. The promoter region can consists of multiple repeats of a cis-element TF binding site, a DNA fragment from the promoter region of a known TF downstream gene, or a DNA fragment containing putative/known TF binding sites. There are several ways that a TF can be activated, such as through extracellular stimuli or through intracellular signaling pathways. Once activated, the TF translocates to the nucleus and often interacts with relevant co-factors to drive gene expression. Once luciferase is expressed, it can generate light in an enzymatic assay and the amount of light measured is positively correlated with the level of TF activation.