THE EXPRESSION OF A NOVEL, EPITHELIUM-SPECIFIC ETS TRANSCRIPTION FACTOR IS RESTRICTED TO THE MOST DIFFERENTIATED LAYERS IN THE EPIDERMIS

Ets proteins have been implicated in the regulation of gene expression during a variety of biological processes, including growth control, d ifferentiation, development and transformation, More than 35 related p roteins containing the 'ets domain' have now been found which specific ally interact with DNA sequences encompassing the core tetranucleotide GGAA. Although ets responsive genes have been identified in the epide rmis, little is known about their distribution and function in this ti ssue, We have now demonstrated that epidermis and cultured epidermal k eratinocytes synthesize numerous ets proteins, The expression of some of these proteins is regulated as a function of differentiation, Among these is a novel ets transcription factor with a dual DNA-binding spe cificity, which we have called jen. The expression of jen is not only epithelial specific, but it is the only ets protein so far described, and one of the very few transcription factors whose expression is rest ricted to the most differentiated epidermal layers, We show that two e pidermal marker genes whose expression coincides with that of jen are transregulated by this protein in a complex mode which involves intera ctions with other transcriptional regulators such as Sp1 and AP1.