Cross-Family Transcription Factor Interactions: An Additional Layer of Gene Regulation

Specific and dynamic gene expression strongly depends on transcription factor (TF) activity and most plant TFs function in a combinatorial fashion. They can bind to DNA and control the expression of the corresponding gene in an additive fashion or cooperate by physical interactions, forming larger protein complexes. The importance of protein-protein interactions between members of a particular plant TF family has long been recognised; however, a significant number of interfamily TF interactions has recently been reported. The biological implications and the molecular mechanisms involved in cross-family interactions have now started to be elucidated and the examples illustrate potential roles in the bridging of biological processes. Hence, cross-family TF interactions expand the molecular toolbox for plants with additional mechanisms to control and fine-tune robust gene expression patterns and to adapt to their continuously changing environment. Large-scale studies are revealing many cross-family transcription factor (TF) interactions, supporting the idea that they play important roles in plant gene regulatory networks.Novel . in vitro and . in vivo approaches in combination with next-generation sequencing methods accelerate studies on TF functioning.Increasing numbers of TFs that play important roles as hubs connecting different genetic networks are being discovered.