LAUSR

The investigation of the nuclear proteins has always been relevant, because they are involved in the expression, replication, storage, reparation and transmission of genetic information. It is known that sodium butyrate, as an inhibitor of protein deacetylation, leads to acetylation of histones and activates the transcriptional function of chromatin, and also it can effectively inhibit cell proliferation at low concentrations. However, it has been shown that the supplement or deletion of acetyl groups on lysine residues near the cleavage sites can regulate the sensibility of histones to proteolysis in chromatin. In the present work, the differences between 24-h seedlings of spring wheat and winter wheat in allocation of Arg-X proteolytic activity in trypsin-like complexes extracted from the fractions of non-histones and histones isolated from the nuclear structures (nucleoplasm, chromatin loosely and tightly bound and nuclear matrix) were shown. It is possible that the appearance of additional Arg-X proteolytic activity which we found in the non-histone and histone fractions that we were isolated primarily from the chromatin loosely bound and from the nuclear matrix are linked to increased histone acetylation under conditions of deacetylation inhibition of nuclear proteins. We suggest the revealed changes of Arg-X proteolysis may be associated with assembly of nucleosomes and possibly nucleosome control of gene expression.