Chromatin proteins of rat preputial-gland: acute changes in response to estrogen

The effects of estradiol-17 beta (E2 beta) at 2 or 15 min in vivo on chromatin proteins of rat preputial-gland were analyzed by a battery of electrophoretic methods. Among histones, E2 beta/control ratios for major bands of H1 decreased substantially between 2 and 15 min. In contrast, ratios of H4 increased (P less than 0.01), whereas, except for losses by 2 min in a H2B-like component and in H3.1, other core histones were unchanged. Among 0.35 M NaCl-soluble proteins, components at 34K-mol. wt and less than 21K -mol wt were increased after 2 min of E2 beta. The bulk of the hormone-responsive low-molecular weight proteins was basic in charge. Electrophoretic correlates of 6 basic lysosomal proteins corresponded to those of low-molecular weight salt-soluble chromatin proteins. Selective proteolysis initiated in vivo by E2 beta depleted some tightly-bound nonhistone proteins.