The Arabidopsis red and far-red photoreceptor phytochrome B is known to regulate gene expression indirectly by modulating the abundance of a family of basic helix-loo-helix transcriptional regulators called PHYTOCHROME-INTERACTING FACTORs (PIFs). In this study published in Nature Communications, we report a new plant light signaling mechanism, in which phytochrome B controls light-responsive genes via direct repression of the transcription activity of PIF3. We also found surprisingly that the transcription activation domain (AD) of PIF3 resembles those found in animal and yeast activators, such as p53 and Gcn4. These new findings suggest the unexpected conservation of sequence-specific ADs between animal, fungal, and plant kingdoms.
This project was initiated more than 8 years by Lingyu Long, a research associate, who began to map the AD in PIF3. Chan Yul Yoo continued and finished the project with the help of Jiangman He and Qing Sang, who carried out detailed studies on the similarities between the PIF3 AD and those in p53 and Gcn4. Yongjian Qin, Jean Ae Kim, Joseph Hahm, and Emily Chong (an undergraduate researcher) also participated in the project. Congratulations to all of you!
This project could not have been done without our collaborators, including Xuemei Chen at UC Riverside, Beixin Mo from Shenzhen University, Akira Nagatani from Kyoto University, Lucia Strader and Nicholas Morffy from Duke Biology, and Pei Zhou from Duke Medical School. Many thanks to all of our collaborators for their critical contributions and kind help!
Here is the link to the paper: https://www.nature.com/articles/s41467-021-25909-5.pdf.