Structure and Regulation of the c-jun Promoter
The c-jun proto-oncogene, the cellular homo-logue of the avian v-jun gene, was first identified in murine fibroblasts as a member of this family of genes. Enhanced c-jun gene expression is not always directly correlated with induction of cell proliferation. The positive autoregulatory loop of activator protein (AP-1) on the c-jun promoter is an attractive model for signal amplification and conversion of transient early events, generated at the cell surface by receptor stimulation, into longer term affects on gene expression. The AP-1 binding sites are potential targets for negative c-jun regulation. The response of a human c-jun promoter construct containing only 132 bp of upstream sequences is similar to that of the endogenous c-jun gene. The cloning of distinct mammalian c-jun genomic sequences has revealed that the general organization of human, rat, mouse, and chicken c-jun promoters is strongly conserved.