DNA Sequences Required for Hormonal Induction of Rat 2u-globulin Genes

The hormonal control of the synthesis of specific proteins has remained a fruitful model system for the study of differential gene expression in higher eukaryotes. The generally accepted model for the molecular mechanism of action of steroid hormones involves the following steps: (1) The steroid enters the cell and binds, in the cytoplasm, to a high-affinity receptor protein; (2) the steroid-receptor complex enters the nucleus and binds to high-affinity sites in the chromatin; and (3) this interaction of the steroid-receptor with the chromatin induces the expression of a few specific genes. Implicit in this model is the assumption that the steroid-receptor complex should show specific binding to sites in or near the target genes, and thus the information necessary for a gene to respond to a hormone should be contained in the DNA sequences in or immediately around the gene. With the advent of recombinant DNA technology, we have been...