Intracellular distribution of hepatic glucokinase and glucokinase regulatory protein during the fasted to refed transition in rats

We have studied the intracellular distribution in vivo of glucokinase (GK) acid glucokinase regulatory protein (GKRP) in livers of fasted and refed ra ts, using specific antibodies against both proteins and laser confocal fluo rescence microscopy, GK was found predominantly in the nucleus of hepatocyt es from starved rats. GK,vas translocated to the cytoplasm in livers of 1- and 2-h refed animals, but returned to the nucleus after 4 h, GKRP concentr ated in the hepatocyte nuclei and its distribution did not change upon refe eding, These results show that, in physiological conditions, GKRP is presen t predominantly in the nuclei of hepatocytes and that the translocation of hepatic GK from and to the nucleus is operative in vivo. (C) 1999 Federatio n of European Biochemical Societies.