Balogh, Arpad and Wong, Joshua H. and Wötzel, Christiane and Soll, Jürgen and Cséke, Csaba and Buchanan, Bob B.
Metabolite-mediated catalyst conversion of PFK and PFP. a mechanism of enyme regulation in green plants.
In: FEBS Letters, Vol. 169, No. 2: pp. 287-292
Metabolites known to occur in the cytosol of photosynthetic leaf cells were found to mediate the reversible conversion of pyrophosphate—D-fructose-6-phosphate 1-phosphotransferase (PFP) to phosphofructokinase (PFK) in partially purified preparations from spinach leaves. Preincubation of PFP with fructose 2,6-bisphosphate, ATP or fructose 6-phosphate converted PFP to PFK. The reverse reaction (PFK → PFP) was promoted by UDP-glucose plus pyrophosphate. These conversions in catalytic capability were accompanied by changes in molecular mass and charge. The results are in accord with the view that the alterations in PFP and PFK activity, provisionally called ‘metabolite-mediated catalyst conversion’, represent a regulatory mechanism to direct left cytosolic carbon flux in either the biosynthetic or degradatory direction.