Biopolymers and cell. 1985. Volume 1. № 3. 141 - 146
A. K.aravanov
HISTONE HI AND TRANSCRIPTIONALLY ACTIVE CHROMATIN REGIONS A.
Summary
The method of limited digestion of mouse spleen nuclei with DNAse I combined with electrophoretic analysis of proteins released from nuclei is used to investigate the par¬ticipation of HI histone in the organization of transcriptionally active chromatin regions. The data obtained show that transcriptionally active chromatin regions digested under applied conditions do not contain at all or contain insignificant amounts of HI histone. Surprisingly, 0.35 M NaCl extraction of nuclei following selective extraction of HI his¬tone at pH 3.0 is also found to result in the release of nucleosomal core histones possib¬ly enriched in hyperacetylated species. It is proposed that while HI histone is not invol¬ved in the organization of transcriptionally active regions at the level of primary nucleo-some fibre it may play an essential role in their organization at higher levels of chroma-• tin packaging in nuclei participating in the stabilization of interactions between modified species of histones and DNA.