Characterization of isoforms of hexose kinases in rice embryo

Hexose kinases in rice embryos have been characterized. Six isoforms were d etected: i.e. three glucokinases (GK1-3), two hexokinases (HK1 and HK2) and one fructokinase (FK1). Out of these, CK3, HK1 and HK2 were inhibited by m annoheptulose and glucosamine, known inhibitors of hexokinase activity. The se inhibitors are also known to be modulators of sugar sensing processes. T he results suggest that GK3, HK1 and HK2 may play a role in sensing the cel lular sugar status in the rice embryo. (C) 2000 Elsevier Science Ltd. All r ights reserved.