期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1978
卷号：75
期号：10
页码：4896-4900
DOI：10.1073/pnas.75.10.4896
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The estrogen receptor (E2R) from rabbit uterus has an enhanced affinity for BrdUrd-substituted DNA compared to unsubstituted DNA. Increasing levels of BrdUrd substitution (from 0 to 100%) in a DNA sample are associated with increasingly tighter binding of E2R to that DNA as measured by equilibrium competition experiments and by rates of dissociation (or receptor transfer experiments). Although the rates of dissociation of E2R-DNA complexes vary greatly, depending on the BrdUrd-substitution level in the DNA, no differences were detected between the rates of association of E2R with unsubstituted and fully BrdUrd-substituted DNA. The E2R-DNA complex dissociates more rapidly in 150 mM KCl than in 50 mM KCl; but, at both ionic strengths, BrdUrd substitution in the DNA confers enhanced stability on the complex. The demonstration that a specific mammalian regulatory protein has an enhanced affinity for BrdUrd-substituted DNA further strengthens the possibility that BrdUrd modulates gene expression through an altered binding of regulatory proteins.
