Description
C-Jun is the name of a gene and protein which, in combination with c-Fos, forms the AP-1 early response transcription factor. It was first identified as the Fos-binding protein p39 and only later rediscovered as the product of the c-jun gene. It is activated through double phosphorylation by the JNK pathway but has also a phosphorylation-independent function. C-Jun knockout is lethal, but transgenic animals with a mutated c-Jun that cannot be phosphorylated (termed c-JunAA) can survive.The growth- promoting activity of c-jun is mediated by repression of tumor suppressors, as well as up-regulation of positive cell cycle regulators. Mostly, c-jun is a positive regulator of cell proliferation, whereas JunB has the converse effect. Recombinant c-jun was expressed in aBaculovirussystem and purified by an affinity column in combination with FPLC chromatography. The purified recombinant protein contains no detectable protease, DNase, and RNase activity