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 the MAPK response Pathway.
 
The ternary complex factor (TCF) Elk-1 is a transcription factor that is associated with a dimer of serum response factor (SRF) at the SRE site, and its phosphorylation occurs at specific residues in response to mitogen-activated protein kinases (ERKs/MAPKs), including c-Jun-N terminal kinase (JNK) and p38/MAPK pathway. Epidermal growth factor (EGF) receptor stimulation results in nuclear accumulation of activated ERK, where it binds to and phosphorylates Elk-1, phosphorylation of Elk-1 increases its transcriptional activity, leading to the transcription of growth-related proteins, most notably c-Fos. Signosis has launched ELK luciferase Reporter HEK293 stable cell line to monitor ERKs/MAPKs pathway.
 
Signosis has developed ELK luciferase reporter HEK293 stable cell line by co-transfecting ELK luciferase reporter vector with three repeats of ELK DNA binding element and hygromycin expression vector. The hygromycin resistant clones were subsequently screened for EGF-induced luciferase activity. The cell line can be used as a reporter system for monitoring ELK activation triggered by stimuli treatment.
 
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.