Role of the transcription factor AP-1 in melanoma differentiation

Although the molecular details remain to be elucidated, temporal changes in gene expression that result in discrete biochemical alterations and growth arrest are primary determinants of terminal cell differentiation. The cont rol of gene expression is inextricably associated with proteins that can in itiate or inhibit gene transcription. Specific genes contain within their p romoter regions, DNA sequences that permit the binding of transactivating a nd transinhibiting proteins that can initiate or suppress transcription, re spectively. Activating protein-1 (AP-1), a dimeric complex consisting of pr oteins encoded by the Jun and Fos gene families, is a transcription factor induced by a variety of signals, including those eliciting proliferation, d ifferentiation and programmed cell death (apoptosis). We presently review t he potential role of AP-1 proteins in differentiation with specific emphasi s on melanoma differentiation.