NUCLEAR LOCATION OF THE REGULATORY PROTEIN OF GLUCOKINASE IN RAT-LIVER AND TRANSLOCATION OF THE REGULATOR TO THE CYTOPLASM IN RESPONSE TO HIGH GLUCOSE

Rat liver is known to contain a regulatory protein (RP) that inhibits glucokinase Summary: competitively with respect to glucose. By an immu nohistochemical technique and by cell fractionation in glycerol, we in vestigated the distribution of RP in rat liver and its changes in resp onse to high glucose. RP was detected almost exclusively in the nuclei of the parenchymal cells of both fed and fasted rats. In situ perfusi on of the liver with 20 mM glucose for 10 min caused a marked decrease in nuclear RP and an increase in cytoplasmic RP. These results indica te that RP is present predominantly in the nuclei of hepatocytes and i s translocated from the nucleus to the cytoplasm in response to high g lucose. (C) 1995 Academic Press, Inc.