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Regulation of Rubisco activity in vivo
Author(s) -
Salvucci Michael E.
Publication year - 1989
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1989.tb05993.x
Subject(s) - rubisco , photosynthesis , carbon fixation , chloroplast , biochemistry , pyruvate carboxylase , oxygenase , biology , regulator , ribulose , chemistry , enzyme , gene
Ribulose‐1,5‐bisphosphate carboxylase/oxygenase (Rubisco) is not able to achieve and maintain adequate CO 2 and Mg 2+ activation under physiological conditions. Higher plants and green algae contain Rubisco activase, a soluble protein which not only facilitates Rubisco activation in situ but also regulates enzyme activity in response to irradiance and other factors. Regulation of Rubisco activity by modulation of activation state coordinates the rate of CO 2 fixation with the rate of substrate regeneration. This regulation may be required to ensure that the levels of photosynthetic metabolites in the chloroplast are optimal for photosynthesis under a variety of environrmental conditions. Some plant species also appear to regulate Rubisco activity by synthesizing 2‐carboxyarabinitol 1‐phosphate, an inhibitor of Rubisco in the dark. This inhibitor may function primarily as a regulator of metabolite binding in the dark rather than as a modulator of Rubisco activity in the light.