jun:Oncogene and Transcription Factor

Publisher Summary This chapter discusses the structure of the cellular and retroviral jun genes and their relationship to other transcriptional regulators. The interaction between the jun and fos proteins, and the control and oncogenic potential of jun are also presented. In the cell the fos protein is associated with a cellular protein, p 39. Together with p 39, the fos binds sequence specifically to DNA and can trans-activate genes. By itself, however, the fos protein does not show specific DNA binding. DNA affinity precipitation and gel retardation assays in conjunction with immunoblots of the bound proteins have shown that the target site for the fos – p 39 complex is the AP-1 consensus sequence. The p 39 precipitated from the cell with anti- jun sera and p 39 precipitated with anti- fos serum, as part of the fos – p 39 complex have identical tryptic peptide maps. Therefore, p 39 and jun are considered to be identical.