Abstract
The two NADP +-dependent glyceraldehyde-3-phosphate dehydrogenases present in the green alga Chlorella fusca, namely, the phosphorylating (chloroplastic) enzyme and the non-phosphorylating (cytosolic) enzyme, are differently affected by the trophic conditions prevailing in the cell cultures. The addition of metabolizable sugars to cell cultures growing in the light promotes a marked decrease of the phosphorylating enzyme activity down to a barely detectable cellular level. In contrast, the cellular level of the non-phosphorylating enzyme is even enhanced in the presence of such sugars. These effects are not observed, however, with a number of non-assimilable sugar analogs. After sugar removal, a recovery of the phosphorylating activity-in a process which is inhibited by cycloheximide but not by lincomycin- is observed in illuminated cells but not in darkness, thus indicating a light-dependent nuclear synthesis of the chloroplastic enzyme. It seems therefore that the two dehydrogenases are adaptative enzymes subject to differential regulation by nutritional conditions.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
More From: Biochemical and Biophysical Research Communications
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.