期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:1982
卷号:79
期号:14
页码:4322-4326
DOI:10.1073/pnas.79.14.4322
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:Fructose 2,6-bisphosphate (Fru-2,6-P2), a regulatory metabolite discovered in animal cells and recently reported to occur in etiolated seedlings, was found to be present in the cytoplasmic fraction of leaves of spinach and peas (typical C3 plants, in which a three-carbon carboxylic acid is a major early photosynthetic product). At concentrations approximating those calculated to occur physiologically, Fru-2,6-P2 modulated two enzymes of the leaf cytoplasm: (i) Fructose-1,6-bisphosphatase (EC 3.1.3.11 ), a key enzyme of sugar synthesis, was competitively inhibited by Fru-2,6-P2, and (ii) pyrophosphate-linked phosphofructokinase (inorganic pyrophosphate-D-fructose-6-phosphate 1-phosphotransferase, EC 2.7.1.90 ), a cytoplasmic enzyme that now seems important in glycolysis of C3 plants, was activated by Fru-2,6-P2. There was no indication of a role for Fru-2,6-P2 in photosynthesis of either chloroplasts or oxygenic prokaryotes. The results suggest that Fru-2,6-P2 functions in the regulation of glycolysis and gluconeogenesis (carbohydrate synthesis) in the cytoplasm of leaves of C3 plants.