Biopolymers and cell. 1985. Volume 1. № 4. 213 - 218

G. A. Romanov

STEROID-RECEPTOR COMPLEXES AND MECHANISM FOR REGULATION OF THE EUCARYOTIC GENOME TRANSCRIPTION

Summary

    The in vitro and in vivo interaction of steroid-receptor complexes with nucleic acids and chromatin is studied. The highly purified glucocorticoid-receptor complex is shown to possess a pronounced selectivity of its association with nucleic acids depending on their base composition and sequence. It is stated that the rat liver glucocorticoid receptors bind to definite sites of homologous DNA with an increased affinity; these sites are involved into the of transcriptionaly active chromatin under the effect of in vivo glucocorticoids on living cells. Studies of DNA methylation level in rat liver and its chromatin sensitivity to DNAase I during hormonal induction, have permitted concluding that hormone-responsive chromatin loci possess a distinct «potentially active* conformation. Thus, hormonal responsiveness of genes depends on DNA sequence as well as on the way of their organization within chromatin. Intracellular RNA may compete with DNA for receptor binding and thereby moderate the intensity of hormonal influence on chromatin.