背景介绍 Colony Stimulating Factor 1 Receptor (CSF1R, CSFR, CD115, M-CSF-R) is a single-pass tyrosine kinase transmembrane receptor which is part of the type III protein tyrosine kinase receptor family. CSF1R is activated by either of two cytokines, CSF1 (MCSF; CSF-1) and IL-34 (IL34), causing homodimerization and activation of downstream kinase activity. CSF1R is expressed on the surface of monocytes and macrophages, and its activation controls the growth, function, and differentiation of macrophages. This interaction is used by numerous cancer types, such as diffuse-type tenosynovial giant cell tumors (dt-GCT), to evade the immune system. By overexpressing the cytokine CSF1, these cells drive the development and survival of Tumor-Associated Macrophages (TAMs), which in turn suppress the local immune response to the cancer. Activation of CSF1R by its ligand initiates a vast array of intracellular activity, including activation of the MAPK/ERK signaling pathway. When phosphorylated by ERK, Elk1 forms a complex with Serum Response Factor (SRF) and binds to Serum Response Element (SRE), resulting in the expression of numerous mitogen-inducible genes. 产品介绍 The CSF1R SRE HEK293 recombinant cell line has been transfected with full-length human CSF1R cDNA (NP_005202) under a CMV promoter for high constitutive expression. The SRE-luciferase reporter is also stably integrated into the genome. The firefly luciferase gene is controlled by 4 copies of the Serum Response Element upstream of a minimal promoter. Upon ligand binding, active CSF1R will initiate the MAPK/ERK signaling pathway, leading to expression of the SRE-controlled luciferase reporter.