אסיף מאגר המחקר החקלאי

Divergent fructokinase genes are differentially expressed in tomato

Year:

1997

Source of publication :

Authors :

Volume :

113

Co-Authors:

Kanayama, Y., Mann Laboratory, Department of Vegetable Crops, University of California, Davis, CA 95616, United States, Faculty of Agriculture, Tohoku University, Aoba-ku, Sendai 981, Japan
Dai, N., Dept. of Fld. Crops and Nat. Rsrc., Volcani Center, Bet Dagan, 50250, Israel
Granot, D., Dept. of Fld. Crops and Nat. Rsrc., Volcani Center, Bet Dagan, 50250, Israel
Petreikov, M., Department of Vegetable Crops, Volcani Center, Bet Dagan, 50250, Israel
Schaffer, A., Department of Vegetable Crops, Volcani Center, Bet Dagan, 50250, Israel
Bennett, A.B., Mann Laboratory, Department of Vegetable Crops, University of California, Davis, CA 95616, United States

Facilitators :

Link :

Abstract:

Two cDNA clones (Frk1 and Frk2) encoding fructokinase (EC 2.7.1.4) were isolated from tomato (Lycopersicon esculentum). The Frk2 cDNA encoded a deduced protein of 328 amino acids that was more than 90% identical with a previously characterized potato (Solanum tuberosum) fructokinase. In contrast, the Frk1 cDNA encoded a deduced protein of 347 amino acids that shared only 55% amino acid identity with Frk2. Both deduced proteins possessed an ATP-binding motif and putative substrate recognition site sequences identified in bacterial fructokinases. The Frk1 cDNA was expressed in a mutant yeast (Saccharomyces cerevisiae) line, which lacks the ability to phosphorylate glucose and fructose and is unable to grow on glucose or fructose. Mutant cells expressing Frk1 were complemented to grow on fructose but not glucose, indicating that Frk1 phosphorylates fructose but not glucose, and this activity was verified in extracts of transformed yeast. The mRNA corresponding to Frk2 accumulated to high levels in young, developing tomato fruit, whereas the Frk1 mRNA accumulated to higher levels late in fruit development. The results indicate that fructokinase in tomato is encoded by two divergent genes, which exhibit a differential pattern of expression during fruit development.

Note:

Related Files :

Related Content

More details

You may also be interested in