
TY  - JOUR
A1  - furumoto, tsuyoshi 
A1  - Ito, Masaki 
A1  - Teramoto, Maki 
A1  - Izui, Katsura 
A1  - Nishida, Ikuo 
A1  - Watanabe, Akira 
T1  - In Vivo Phosphorylation of Arabidopsis thaliana 6-phosphofructo-2-kinase/fructose-2,6-bisphosphate 2-phosphatase
JF  - Science Access
JO  - 
Y1  - 2001
VL  - 3
IS  - 1
SP  - 
EP  - 
KW  - 
UR  - https://doi.org/10.1071/SA0403383 
N2  - Fructose 2,6-bisphosphate (F2,6BP) is a non-metabolic sugar-phosphate ubiquitously found in eukaryotes. This compound regulates the balance of glycolysis and gluconeogenesis. In plants, its physiological functions are thought to be an inhibition of sucrose synthesis in source leaves and to be an activation of glycolysis in sink organs. Both synthesis and degradation of F2,6BP are catalyzed by a bifunctional enzyme, 6-phosphofructo-2-kinase/fructose-2,6-bisphosphate 2-phosphatase (PFK 2/FBPase 2; EC 2.7.1.105/EC 3.1.3.46). In animals and yeast, it is well known that several isozymes are regulated by protein phosphorylation. In plant enzymes, on the other hand, it had been thought that the protein phosphorylation is not involved in the enzymatic regulation. An Arabidopsis cDNA for PFK 2/FBPase 2 was isolated and expressed in E. coli. Antisera prepared from the recombinant enzyme identified 96-kD and 92-kD protein bands of plant crude protein extracts. Results of in vitro calf intestine alkaline phosphatase treatment and an immunoprecipitation of the crude extracts from [32P]-labeled whole plants revealed that the 96-kD protein was phosphorylated in vivo. Immunoblot analysis showed that the 96-kD protein was enriched in younger leaves than in older leaves. These results indicate that Arabidopsis enzyme is phosphorylated. Now we try to identify the biochemical effects of this phosphorylation, especially whether this phosphorylation can change the enzymatic activities or not. 
ER  -

