Abstract

TTG1 -WDR proteins are scaffold proteins that aid the formation of transcription factor protein complexes. TTG1 is the most famous member of this WDR family in Arabidopsis thaliana, and was isolated in this department in 1999. Since then, several groups have worked on this transcription factor and thoroughly characterised its numerous functions. The ttg1 mutant shows numerous defects such as lack of anthocyanins, lack of trichomes on the leaf blades, increased number of root hairs and lack of pigments in the seeds. These diverse functions are delivered by the interaction of the TTG1 protein with MYB and bHLH transcription factors. Furthermore the two closest relatives of TTG1 in Arabidopsis regulate circadian clock by binding with TCP transcription factors to influence the expression of a central oscillator of the clock. We have investigated the surprising evolution of these numerous diverse functions and have uncovered the central role of these proteins in circadian clock regulation.