Abstract
Effects of light on expression of one of the glycolytic enzymes, fructose-1.6-bisphosphate aldolase (fbaA) were investigated in Synechocystis sp. PCC6803. The fbaA mRNA was induced by light pulse of 5 min in the presence of glucose, while glucose addition in the dark was not effective for induction of fbaA. Therefore, both light and glucose were required for the full induction of fbaA transcription. One of the response regulators, sll1330, was demonstrated to be involved in regulation of fbaAgene expression by light pulse and glucose.
Expression of sll1330 gene were induced by glucose irrespective of light conditions, suggesting that the amount of sll1330 proteins increases in the presence of glucose and that sll1330 protein interacts with components involved in the signal transduction of light pulse.
We constructed mutants that expresses sll1330 even in the absence of glucose. The transcript of fbaA of this mutant appeared much more abundant than that of wild type. These results suggest that
fbaA is expressed by light pulse without glucose if sll1330 is expressed.
