Carnegie Scientists Discover a New Component of a Plant Steroid-activated Pathway

Scientists have been investigating the series of chemical signals that the group of plant hormones called brassinosteroids send from a protein on the surface of a plant cell to the cell's nucleus. Understanding the brassinosteroid pathway will help scientists understand plant growth and develop strategies to enhance food and energy crop production.

Carnegie scientists Tae-Wuk Kim and Zhiyong Wang found another link in this chain and published the results of their study in Molecular Cell. The research team identified a protein called Constitutive Differential Growth1 (CDG1), which adds a phosphate to another protein BSU1. Previous studies have revealed that BSU1 deactivates another protein called BIN2. When BIN2 is turned on, it blocks the transcription factors BZR1 and BZR2. When BZR1 and BZR2 are inactive, they are unable to enter the plant cell's nucleus. When BIN2 is turned off by BSU1, BZR1 and BZR2 bind to DNA molecules in the nucleus and promote various gene activities.

"Together with our previous work, these results provide the detailed mechanisms of brassinosteroid signaling," Wang said. "Because this system of brassinosteroid-activated proteins is one of the best-understood chemical pathways in plant physiology, these results could help scientists understand many other plant cell systems."

Read more at http://carnegiescience.edu/news/new_component_plant_steroidactivated_pathway_discovered.