PHOSPHORYLATION OF HMG PROTEINS DURING CHANGES IN CHROMATIN TRANSCRIPTION ACTIVITY IN NEURONAL AND GLIAL NUCLEI OF RAT-BRAIN

The level of caMP-independent phosphorylation of chromatin and the amo unt and degree of phosphorylation of weakly bound nonhistone protein a re much higher in neuronal nuclei than in glial nuclei The memory stim ulating agent ethylnorantipheine (ethymizol) increases chromatin phosp horylation in neurons. The memory deteriorating agent allylnorantiphei ne decreases this phosphorylation. No influence of antipheines on phos phorylation of weakly bound proteins in glial chromatin was observed I t is known that transcription in neuronal nuclei but not in glial nucl ei is activated by ethymizol and inhibited by allylnorantipheine. The activity of purified N I and N II casein kinases in neuronal chromatin are much higher than in glial chromatin. Antipheines do not influence the activity of N I casein kinase, and they selectively modulate HMG protein 14 phosphorylation by N II casein kinase of neuronal and glial chromatins. Participation of phosphorylated HMG proteins and chromati n casein kinases in regulation of genome activity is discussed.