c-Jun is a component of the transcription factor AP-1, which binds and activates transcription at TRE/AP-1 elements. The transcriptional activity of c-Jun is regulated by phosphorylation at Ser63 and Ser73 (1,2). Extracellular signals including growth factors, transforming oncoproteins and UV irradiation stimulate phosphorylation of c-Jun at Ser63/73 and activate c-Jun-dependent transcription. Mutation of Ser63/73 renders c-Jun nonresponsive to mitogenic and stress-induced signaling pathways. The MAP kinase homologue SAPK/JNK binds to the amino-terminal region of c-Jun and phosphorylates c-Jun at Ser63/73. In addition, the activity of SAPK/JNK is stimulated by the same signals that activate c-Jun (3,4).
c-Jun also plays a role in Neuropathic Pain.
Image: Detection of c-Jun with SP15102.Lysates from human HeLa (1), K562 (2), and MDA-MB-468 (3) cells were resolved by SDS-PAGE, transferred to Immobilon-P membrane, and immunoblotted with 0.5 ug/mL sheep anti-c-jun. A 1 minute exposure to film is shown. Band for c-Jun is ~ 40KDa.