Modulation of the Nucleosome Structure by Histone Acetylation

Abstract

A rapid procedure for the isolation of core particles from Chinese hamster ovary cells is described which permits measurements, usually at the day of their preparation. Particles of 145 ± 5 base pairs, derived from interphase cells, will be compared with the analogue specimens from butyrate‐treated cells, metaphase cells and a standard preparation from chicken erythrocytes. Butyrate cause an increase in the acetylation of histones H3 and H4, which induces alterations of the interhistone and histone‐DNA interactions. Changes in the interhistone contacts, correlated to an extension of a‐helical segments, lead to an altered accessibility of the H3 cysteine side‐chains and to a different histone displacement by protamines. On the other hand, histone‐DNA contacts are loosened in parts and this is particularly evident from the changes in the premelting region of a thermal‐denaturation profile. Copyright © 1980, Wiley Blackwell. All rights reserved