Skip to main content
. 2012 Jun 12;287(31):25917–25926. doi: 10.1074/jbc.M112.368001

FIGURE 4.

FIGURE 4.

Transcriptional repression positively correlates with rhythm amplitude. A, dual luciferase reporter assay in Cry1−/−:Cry2−/− fibroblasts. For Cry1 expression, three different promoters were tested. Each Cry construct was cotransfected with P(SV40)-dLuc (control) or P(Per2)-dLuc reporter. A Renilla luciferase (RLuc) was added in each transfection to normalize transfection efficiency. Under the control of the Cry1-phase promoter, CRY1 acted as a much more potent repressor than CRY2. Mean ± S.D. (error bars) of two independent experiments are shown (n = 3 for each experiment). B, repression activities of various Cry chimeras and mutants. Dual luciferase reporter assay was done as in A. The constructs that rescued rhythms exhibited stronger repression, similar to Cry1, whereas those that failed to rescue rhythms exhibited much weaker repression, similar to Cry2. Mean ± S.D. (error bars) of two independent experiments are shown (n = 3). C, representative bioluminescence records from Cry1−/−:Cry2−/− fibroblasts expressing various Cry chimeras and mutants. The Cry rescue assay was performed as described in the legend to Fig. 1B. D, relative amplitudes of rescued rhythms in C. Mean ± S.D. (error bar) of two independent experiments are shown (n = 3). E, relative rhythm amplitude (x axis) is plotted against relative repression activity (y axis). Rhythm amplitude bears a positive correlation with transcriptional repression by various CRYs. Mean ± S.D. (error bar) of two independent experiments are shown (n = 3).