GLYCERALDEHYDE-3-PHOSPHATE DEHYDROGENASE IS REGULATED ON A DAILY BASIS BY THE CIRCADIAN CLOCK

Circadian clocks function to govern a wide range of rhythmic activitie s in organisms, An integral part of rhythmicity is the daily control o f target genes by the clock, Here we describe the sequence and analysi s of a novel clock-controlled gene, ccg-7, showing similarity to glyce raldehyde-3-phosphate dehydrogenase (GAPDH), a glycolytic enzyme widel y used as a constitutive control in a variety of systems, That ccg-7 e ncodes GAPDH was confirmed by demonstrating that in vitro synthesized CCG-7 possesses GAPDH activity. Rhythms in both ccg-7 mRNA accumulatio n and CCG-7 (GAPDH) activity are observed in a clock wild-type strain where the peak in GAPDH activity lags several hours behind the peak in ccg-7 mRNA accumulation in the late night, Together with our previous observation that ccg-7 mRNA is not developmentally regulated, we show that ccg-7 is not induced by environmental stresses such as glucose o r nitrogen deprivation (which also trigger development), heat shock, o r osmotic stress, Thus, the finding that GAPDH is clock-regulated poin ts to a specific role for the circadian clock in controlling aspects o f general metabolism and provides evidence for circadian regulation of a gene found in most living organisms.