%0 Journal Article %A Herrero, P. %A Fernández, R. %A Moreno, F. %T The Hexokinase Isoenzyme PII of Saccharomyces cerevisiae is a Protein Kinase %D 1989 %J Microbiology, %V 135 %N 5 %P 1209-1216 %@ 1465-2080 %R https://doi.org/10.1099/00221287-135-5-1209 %I Microbiology Society, %X The HXK2 gene product has an important role in controlling carbon catabolite repression in Saccharomyces cerevisiae. We have raised specific antibodies against the hexokinase PII protein and have demonstrated that it is a 58 kDa phosphoprotein with protein kinase activity. The predict amino acid sequence of the HXK2 gene product has significant homology to the catalytic domain of mammalian and yeast protein kinases. Protein kinase activity was located in a different domain of the protein from the hexose-phosphorylating activity. The hexokinase PII protein level remained unchanged in P2T22D mutant cells (hxk1 HXK2 glk1) growing in a complex medium with glucose. The protein kinase activity of hexokinase PII is regulated by the glucose concentration of the culture medium. Exit from the carbon catabolite repression phase and entry into the derepression phase may be controlled, in part, by modulation of the 58 kDa protein kinase activity by changes in cyclic AMP concentration. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-135-5-1209