Physiological and biochemical aspects of the functioning of Arg-X proteolytic system in the cell nuclei of plants

Plants are structural and biochemical systems in which at each moment of ontogenesis are established inherent only to this plant, the ratio of growth, biorhythmic and morphogenetic processes. The conjugacy of circadian rhythm and the activity of chromatin-modifying enzymes is becoming increasingly important. In this aspect, histones play an important role, since they are able to fine-tune transcriptional programs through a series of accurately organized post-translational modifications that combinatorially regulate chromatin function. It is proved that almost all histones are proteolytically modified. It was shown that differences in the exhibition of activity Arg-X proteolysis between spring and winter seedlings are observed mainly in the fractions of core histones at the level of chromatin tightly bound. The preferential localization of Arg-X protease activity was found in the histone (H3 + H4) block as spring and winter varieties. In addition, activity Arg-X proteolysis at the level of nuclear matrix correlated with the growth characteristics of spring and winter seedlings in coleoptiles and roots growing by cell stretching. Results can be viewed as an illustration of a multi-layered regulatory proteinase network involved in proteolytic processing of nuclear proteins, taking part in circadian spatial and temporal structural changes of chromatin states.