The High Mobility Group Protein HMG I(Y) Is an Essential Structural Component of a Virus-inducible Enhancer Complex

Excerpt

The development of eukaryotic organisms involves the growth and differentiation of functionally distinct cell types in a precise spatial pattern. The morphological and functional specialization of differentiated cells is achieved by cell- or tissue-specific gene expression. In contrast, many genes are turned on specifically in response to extracellular signals such as growth factors or hormones, or to heat shock or virus infection. Recent studies have shown that similar mechanisms are involved in both types of gene expression. For example, dorsal-ventral patterning of the early Drosophila embryo involves a signal transduction pathway that is remarkably similar to the antigen- or cytokine-induced activation of mammalian lymphocytes. In addition, similar signal transduction pathways appear to be involved in the activity of specific morphogens during early development, and in cell-cell interactions during organogenesis. Thus, an understanding of the mechanisms of inducible gene expression is likely to provide important insights into the regulatory mechanisms required...