The DNA binding of plant-specific GROWTH-REGULATING FACTOR transcription factors is stabilized by GRF-INTERACTING FACTOR coactivators.

Abstract

The plant-specific GROWTH-REGULATING FACTOR (GRF) transcription factor family proteins play crucial role in regulating diverse aspects of plant life. The transcriptional activity of GRFs is known to be enhanced through direct interaction with the GRF-INTERACTING FACTOR (GIF) coactivators. However, it remains unclear how the binding to GIF affects the biochemical ability of GRFs. Herein, we present evidence that GIFs also stabilize the DNA binding of GRFs. A combination of biochemical experiments and AlphaFold-predicted structural models suggests that the GIF-binding domain in GRFs may partially restrict their own DNA binding through direct interaction with the DNA-binding domain in the absence of GIFs. These findings deepen our understanding of the GRF:GIF module in plant regulation and provide a basis for strategies to manipulate this module for agricultural and biotechnological applications.