FIGURE 3.

Interactions of TCP transcription factors with components of the circadian clock both within the central clock circuitry and in downstream processes. Class I and class II TCPs are depicted in green and blue, respectively. Known clock components are depicted in gray. Proteins are represented as circles, genes in squares. Dimers are depicted as overlapping circles. CCA1 inhibition by TCP21 is abolished by dimerization of TCP21 with TOC1. The CCA1/LHY dimer inhibits TCP21 expression (Pruneda-Paz et al., 2009). The effect of nine TCPs that bind to the CCA1 promoter in yeast one-hybrid studies is unknown (Pruneda-Paz et al., 2014). Downstream of the clock, TCP/clock component heterodimers regulate rhythmic expression of mitochondrial proteins depending on the number and arrangement of TCP binding sites in the mitochondrial gene promoters (Giraud et al., 2010).